INLINE DUCT FAN, CONTROL SYSTEM, AND METHOD OF CONTROLLING THE SAME

Info

Publication number: 20260243274
Type: Application
Filed: Feb 13, 2026
Publication Date: Aug 20, 2026
Applicant: Research Products Corporation (Madison, WI)
Inventors: Nathan A. Hughes (Madison, WI), Atul P. Kulkarni (Madison, WI), Jacob E. Malesky (Madison, WI), Caroline D. Innes (Madison, WI)
Application Number: 19/540,140

Abstract

An inline duct fan for an HVAC system including a body portion comprising a surface, a first side portion, and a second side portion. The inline duct fan includes the first side portion extending outward from the body portion, with the first side portion including a mounting tab defines one or more first mounting holes therethrough. The inline duct fan includes the second side portion positioned opposite the first side portion and extending outward from the body portion, with the second side portion defining one or more second mounting holes therethrough. The second side portion is configured to be mounted to either ductwork, where the second side portion extends at least partially within the ductwork, or an HVAC device via the one or more second mounting holes. The inline duct fan includes a fan assembly positioned at least partially within the first side portion of the housing.

Description

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63/759,457, filed on February 17, 2025, and U.S. Provisional Patent Application No. 63/943,125, filed on December 17, 2025, the entire contents of which are incorporated by reference herein.

BACKGROUND

The present disclosure relates generally to the field of HVAC systems and components thereof. Specifically, this disclosure relates to inline duct fans, systems utilizing said inline duct fans, and control systems and/or methods of controlling said inline duct fans.

SUMMARY

One embodiment relates to an inline duct fan for an HVAC system, the inline duct fan including a housing including a body portion having a surface, a first flange extending from the surface adjacent to a first side portion, and a second flange extending from the surface adjacent to a second side portion. The first side portion extends outward from the body portion, where the first flange of the body portion extends around the first side portion, and the first side portion includes a mounting tab, where the mounting tab defines one or more first mounting holes therethrough. The inline duct fan includes the second side portion positioned opposite the first side portion and extending outward from the body portion, where the second flange extends around the second side portion, and the second side portion defines one or more second mounting holes therethrough. The second side portion is configured to be mounted to either ductwork, where the second side portion extends at least partially within the ductwork, or an HVAC device via the one or more second mounting holes. The inline duct fan includes a fan assembly including a fan blade and a fan motor, where the fan assembly is positioned at least partially within the first side portion of the housing.

In some embodiments, the first side portion of the inline duct fan is configured to be positioned at least partially within a first duct of the HVAC system such that the first duct extends to the mounting tab of the first side portion, and where the first side portion is mounted to the duct via the one or more first mounting holes of the mounting tab. In some embodiments, the inline duct fan further includes a shroud positioned over the body portion of the housing, with the shroud extending between the first flange and the second flange, and processing circuitry positioned on a surface of the body portion underneath the shroud. In some embodiments, the inline duct fan further includes a shroud positioned over the body portion of the housing, where the shroud defines one or more third mounting holes therethrough. When the second side portion is mounted to the ductwork, the shroud is mounted onto the ductwork via the one or more third mounting holes.

In some embodiments, the inline duct fan further includes processing circuitry configured to control operation of the inline duct fan. The processing circuitry includes a first controller positioned along a circumference of the surface of the body portion of the inline duct fan, with the first controller configured to operate the fan assembly, and a second controller communicably coupled to the first controller and positioned opposite the first controller along the circumference of the surface of the body portion of the inline duct fan, where the second controller is communicably coupled to the HVAC system for controlling the inline duct fan.

Another embodiment relates to a system including a humidifier coupled to ductwork to humidify air, a bypass duct coupled to the humidifier and the ductwork, and an inline duct fan positioned between the ductwork and the humidifier. The inline duct fan includes a first side portion connected to the bypass duct, a second side portion connected to either ductwork, where the second side portion extends at least partially within the ductwork, or the humidifier via one or more mounting holes, and processing circuitry communicably coupled to the humidifier, where the processing circuitry is configured to control operation of the inline duct fan.

In some embodiments, the ductwork includes a return air duct and a supply air duct, and wherein the bypass duct connects the return air duct to the supply air duct for airflow with the ductwork. In some embodiments, the humidifier is coupled to the return air duct and the inline duct fan is connected to the humidifier and the bypass duct, where the bypass duct further connects to the supply air duct. The inline duct fan is configured to move air from the supply air duct through the bypass duct and into the humidifier for humidification and circulation of humidified air through the return air duct. In some embodiments, the humidifier is coupled to the supply air duct and the inline duct fan is connected to the return air duct and the humidifier. The inline duct fan is configured to move humidified air from the humidifier through the bypass duct and into the return air duct. In some embodiments, the humidifier is coupled to the return air duct and the inline duct fan is connected to the supply air duct and the bypass duct, where the bypass duct is further connected to the humidifier. The inline duct fan is configured to move air from the supply air duct through the bypass duct and into the humidifier for humidification and circulation of humidified air through the return air duct. In some embodiments, the humidifier is coupled to the supply air duct and the inline duct fan is connected to the return air duct and the bypass duct. The inline duct fan is configured to move humidified air from the humidifier through the bypass duct and into the return air duct.

In some embodiments, the processing circuitry is configured to receive sensor data indicative of an air humidity within the system, compare the sensor data to an air humidity setpoint, and operate the humidifier and the inline duct fan, based on comparing the sensor data to the air humidity setpoint, to humidify air within the system. In some embodiments, the processing circuitry is configured to receive sensor data indicative of an air humidity within the system, compare the sensor data to an air humidity setpoint, operate the inline duct fan, based on comparing the sensor data to the air humidity setpoint, to operate the inline duct fan for providing air to the humidifier, and operate the humidifier, based on operating the inline duct fan, to humidify air within the system.

In some embodiments, the system further includes a first electrical connection formed between a controller of an HVAC system and a transformer, a second electrical connection formed between the transformer and the humidifier, a third electrical connection formed between the humidifier and the inline duct fan, and a fourth electrical connection formed between the inline duct fan and the controller. In some embodiments, the second electrical connection is formed between an electrical control valve of the humidifier and the transformer and the third electrical connection is formed between the electrical control valve of the humidifier and the inline duct fan, and where the electrical control valve completes the second electrical connection and the third electrical connection when the humidifier operates to provide humidification of air through the system.

Another embodiment relates to a method for humidifying air. The method includes receiving sensor data indicative of an air humidity, comparing the sensor data to an air humidity setpoint, operating an inline duct fan, based on comparing the sensor data to the air humidity setpoint, to operate the inline duct fan for providing air to a humidifier, and operating the humidifier to humidify the air.

In some embodiments, the method further includes mounting the inline duct fan to the humidifier and a bypass duct connected to a supply air duct, where the humidifier is coupled to a return air duct, and where, during operation, the inline duct fan moves air from the supply air duct through the bypass duct and into the humidifier for humidification and circulation of humidified air through the return air duct. In some embodiments, the method further includes mounting the inline duct fan to the humidifier and a bypass duct connected to a return air duct, where the humidifier is coupled to a supply air duct, and where, during operation, the inline duct fan moves humidified air from the humidifier through a bypass duct and into the return air duct. In some embodiments, the method further includes mounting the inline duct fan to a supply air duct and a bypass duct, where the humidifier is coupled to a return air duct and the bypass duct, and where, during operation, the inline duct fan moves air from the supply air duct through the bypass duct and into the humidifier for humidification and circulation of humidified air through the return air duct. In some embodiments, the method further includes mounting the inline duct fan to a return air duct and a bypass duct, where the humidifier is coupled to a supply air duct and the bypass duct, and where, during operation, the inline duct fan moves humidified air from the humidifier through the bypass duct and into the return air duct.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of one embodiment of an inline duct fan in accordance with an illustrative embodiment.

FIG. 2A is a section view of another embodiment of the inline duct fan.

FIG. 2B is a perspective view of a housing the inline duct fan, according to an illustrative embodiment.

FIG. 3 is a rear view of another embodiment of the inline duct fan.

FIGS. 4A-4C are perspective views of another embodiment of the inline duct fan including a fan assembly in accordance with an illustrative embodiment.

FIGS. 4D-4E are perspective views of another embodiment of the inline duct fan in accordance with an illustrative embodiment.

FIGS. 5A-5B are exploded views of the inline duct fan, in accordance with illustrative embodiments.

FIG. 6 is a side view of another embodiment of the inline duct fan.

FIG. 7A is perspective view of an embodiment of an HVAC system including the inline duct fan connected to an HVAC device.

FIGS. 7B is a front view of another embodiment of an HVAC system including the inline duct fan connected to an HVAC device.

FIG. 7C is a section view of another embodiment of the HVAC system including the inline duct fan connected to the HVAC device.

FIG. 8A is a section view of another embodiment of the inline duct fan including processing circuitry.

FIGS. 8B-8C are detailed views of another embodiment of the inline duct fan including processing circuitry.

FIG. 9A is a perspective view of an embodiment of the inline duct fan mounted within an HVAC system, in accordance with an illustrative embodiment.

FIG. 9B is a perspective view of an embodiment of the inline duct fan mounted within an HVAC system, in accordance with another illustrative embodiment.

FIG. 10 is a front view of the inline duct fan mounted within the HVAC system, in accordance with another embodiment.

FIGS. 11A-11D are perspective views of an HVAC system, in accordance with illustrative embodiments.

FIG. 12 is a flowchart depicting a method of installation of an inline duct fan within an HVAC system, in accordance with one embodiment.

FIGS. 13A-13B are schematic diagrams of an inline duct fan electrically connected to an HVAC system, in accordance with an illustrative embodiment.

FIGS. 13C-13D are schematic diagrams of an inline duct fan electrically connected to an HVAC system, in accordance with another illustrative embodiment.

FIG. 13E is a schematic diagram of an inline duct fan connected to an HVAC system, in accordance with another illustrative embodiment.

FIG. 14 is a flowchart depicting a method for humidifying air, in accordance with one embodiment.

FIG. 15 is a flowchart depicting another method for humidifying air, in accordance with another embodiment.

FIG. 16 is a flowchart depicting another method for humidifying air, in accordance with another embodiment.

FIG. 17A is a block diagram of an HVAC system including the inline duct fan, in accordance with an illustrative embodiment.

FIG. 17B is a schematic diagram of an inline duct fan electrically connected to an HVAC system, in accordance with an illustrative embodiment.

FIG. 18 is a flowchart for transitioning between various operating modes of the inline duct fan, in accordance with an illustrative embodiment.

FIG. 19 is a flowchart depicting a method for adjusting airflow within an HVAC system, in accordance with an illustrative embodiment.

FIGS. 20A-20B are flowcharts for determining and/or adjusting a speed of the fan assembly of the inline duct fan, in accordance with an illustrative embodiment.

FIG. 21 is a flowchart depicting a method for adjusting airflow within an HVAC system, in accordance with an illustrative embodiment.

FIG. 22 is a flowchart for determining and/or adjusting a speed of the fan assembly of the inline duct fan, in accordance with an illustrative embodiment.

FIG. 23 is a flowchart depicting a method for controlling operation of the inline duct fan via a plurality of operating modes, in accordance with an illustrative embodiment.

FIG. 24A is a block diagram of a plurality of switches of the inline duct fan, in accordance with an illustrative embodiment.

FIG. 24B is a front view of a fan controller of the inline duct fan including a plurality of switches, in accordance with an illustrative embodiment.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

In an embodiment of an inline duct fan for an HVAC system, the inline duct fan includes a housing including a body portion, and a first side portion and a second side portion extending outward from the body portion in opposite directions. The body portion includes a surface, a shoulder extending from the surface adjacent to the first side portion, and a flange extending from the surface adjacent to the second side portion, where the flange defines one or more mounting holes. The second side portion is configured to be mounted to the ductwork via the one or more mounting holes on the flange and/or an HVAC device via a fastener on the second side portion, where the second side portion is positioned at least partially within the ductwork and/or the HVAC device when mounted thereto. The inline duct fan further includes a fan assembly including a fan blade and a fan motor, where the fan assembly is positioned at least partially within the first side portion of the housing. The inline duct fan is configured to move air through the ductwork and the HVAC device for providing treated air through the HVAC system.

In an embodiment of a system, the system includes a humidifier coupled to ductwork to humidify air, a bypass duct coupled to the humidifier and the ductwork, and an inline duct fan positioned between the ductwork and the humidifier. The inline duct fan includes a first side portion connected to the bypass duct, and a second side portion connected to either the ductwork via one or more mounting holes positioned on a flange adjacent to the second side portion or the humidifier via a fastener positioned on the second side portion. The inline duct fan further includes processing circuitry communicably coupled to the humidifier. The processing circuitry is configured to receive a command for operating the humidifier; operate the humidifier, based on the command, to humidify the air within the system; and operate the inline duct fan, based on the command, to modify airflow through (e.g., move air through) the humidifier.

The inline duct fan is configured to be variably mounted within different configurations of HVAC systems, as the inline duct fan increases the efficiency of said HVAC systems. For example, the inline duct fan may increase the efficiency of a humidifier installed in a bypass humidification system. The inline duct fan improves bypass humidification systems by providing higher humidification levels. The inline duct fan provides an increased and controlled airflow into the humidifier to control the flow of heated air, which optimizes the humidification process. In some embodiments, the inline duct fan may move other types of air through the humidifier (e.g., room temperature air, cooled air).

For the variable mounting arrangements, the inline duct fan includes the second side portion configured with the fastener and/or the mounting holes for variable mounting of the inline duct fan to either ductwork and/or the HVAC device. For example, the fastener may be used to attach the humidifier to the inline duct fan, where the humidifier is attached around the second side portion, while the mounting holes may be used to attach the inline duct fan to ductwork, where the second side portion is at least partially disposed within the ductwork. Because the inline duct fan may be variably mounted, the inline duct fan assists in overcoming installation challenges when there is limited installation space on ductwork for installing the bypass humidification system. For example, the inline duct fan may provide for mounting when there is limited vertical space on the supply air duct or when the ductwork has a shortened height when installed (e.g., limited installation space for the HVAC system), causing the bypass humidification system to be less than optimally installed (e.g., installed on a return air duct). For example, bypass humidification systems may decrease in performance when a humidifier is mounted on a return air duct, compared to mounting on a supply air duct. The inline duct fan may be used when the humidifier is mounted on either the supply air duct or the return air duct. For example, when the humidifier is mounted on the return air duct, the inline duct fan increase the humidification output of the bypass humidification system. The increased humidification output provides advantages of alternative fan powered humidification system, while still pulling warm air from the supply to increase evaporation output, a benefit of bypass humidification systems. Therefore, variably mounting the inline duct fan simplifies installation, and increases the efficiency of an installed bypass humidifcation system, tailored to a resident’s desired HVAC performance (e.g., the inline duct fan may be installed and/or operated with the HVAC system, regardless of the configuration of the HVAC system, as the inline duct fan adaptively adjusts airflow for different HVAC systems).

Inline Duct Fan

Referring to FIGS. 1-2A, an inline duct fan 100 for an HVAC system is depicted. The inline duct fan 100 is configured to modify airflow within and/or move air through the HVAC system (e.g., through ductwork). The inline duct fan 100 includes a housing 102. The housing 102 includes a body portion 103 and a first side portion 104 positioned opposite a second side portion 105, where the first side portion 104 and the second side portion 105 are connected to the body portion 103 and extend outward from the body portion 103 on opposite sides of the body portion 103. The housing 102 defines an interior volume for airflow through the inline duct fan 100. The inline duct fan 100 further comprises a fan assembly 110 coupled to the housing 102 (e.g., within the interior volume). In some embodiments, the fan assembly 110 is positioned at least partially within the first side portion 104 of the housing 102 in a manner such that the fan assembly 110 is offset relative to a central point 115 within the inline duct fan 100. In some embodiments, the fan assembly 110 may be positioned within the housing 102 such that the fan assembly 110 is centered therein (e.g., positioned at the central point 115, etc.).

Referring to FIGS. 1-5B, the second side portion 105 defines one or more mounting holes 135 therethrough. For example, the mounting holes 135 extend into the interior volume of the housing 102. The mounting holes 135 are configured to couple (e.g., via a fastener inserted at least partially therethrough) an HVAC device 120 to the inline duct fan 100. When the inline duct fan 100 is coupled to the HVAC device 120, the HVAC device 120 may extend around the second side portion 105. In some embodiments, the mounting holes 135 may at least partially couple a damper blade 124 of the HVAC device 120 to the inline duct fan 100 (see FIG. 7A). In some embodiments, ductwork may be coupled to the inline duct fan 100 via the mounting holes 135 of the second side portion 105. When the inline duct fan 100 is mounted to ductwork, the ductwork may extend around the second side portion 105.

The inline duct fan 100 further includes a shroud 131. The shroud 131 is positioned to cover the body portion 103 of the housing 102. For example, the shroud 131 may be removable relative to the housing 102. The body portion 103 further includes a surface 133 (e.g., an interior surface), where the surface 133 is positioned underneath the shroud 131 when the shroud 131 is attached to the housing 102. In some embodiments, the shroud 131 may include one or more pieces, where the shroud 131 is formed by assembling the one or more pieces onto the housing 102 of the inline duct fan 100. In some embodiments, the shroud 131 may be integrally formed.

The body portion 103 may include a shoulder 106 (e.g., a first shoulder, a flange, a ridge, etc.) positioned adjacent to the first side portion 104. The shoulder 106 extends around the first side portion 104. In some embodiments, when the inline duct fan 100 is mounted within ductwork, said ductwork may be connected to the first side portion 104 of the inline duct fan 100, where the ductwork extends over the first side portion 104 up to the shoulder 106.

As shown in FIGS. 1-5B, the first side portion 104 of the inline duct fan 100 includes a mounting tab 160 (e.g., a shoulder or second shoulder, a flange, etc.). For example, the mounting tab 160 may extend around a perimeter (e.g., a circumference) of the first side portion 104. The mounting tab 160 is configured to couple the inline duct fan 100 (e.g., the first side portion 104 thereof) to ductwork. The mounting tab 160 may be spaced apart from the shoulder 106, such that the mounting tab 160 is positioned outward from the shoulder 106 (e.g., in a direction away from the second side portion 105, etc.).

When the inline duct fan 100 is attached to ductwork, said ductwork may be circular ductwork that extends to the mounting tab 160 of the first side portion 104. For example, the ductwork may extend around at least part of the first side portion 104 underneath the mounting tab 160. The mounting tab 160 may define one or more mounting holes 162 at least partially therethrough. The one or more mounting holes 162 are configured for coupling the ductwork to the inline duct fan 100 (e.g., via one or more fasteners inserted therethrough, such that a fastener extends through one of the one or more mounting holes 162 and the ductwork extending around the first side portion 104 of the inline duct fan 100 and/or underneath the mounting tab 160, etc.).

In some embodiments, the ductwork may extend to the shoulder 106 of the first side portion 104 when connected to the inline duct fan 100. In some embodiments, the shroud 131 includes a side surface 108 positioned facing the first side portion 104. The side surface 108 extends around the first side portion 104 and is defined between the shoulder 106 and an outer circumference of the shroud 131. When the inline duct fan 100 is mounted within ductwork, the ductwork may extend to the side surface 108.

In some embodiments, such as shown in FIGS. 2B and 5A-5B, the body portion 103 includes a flange 130 (e.g., a shoulder, such as a second or third shoulder, etc.) positioned adjacent to the second side portion 105. The shroud 131 may be coupled to the housing 102 substantially between the shoulder 106 and the flange 130. For example, the first side portion 104 may be defined from the shoulder 106 to a first end of the housing 102. The second side portion 105 may be defined from the flange 130 to a second end of the housing 102.

In some embodiments, the flange 130 may include the one or more mounting holes 135, where the mounting holes 135 extend through the flange 130 for attachment of the inline duct fan 100 to ductwork. The flange 130 of the body portion 103 includes a flange surface 107, where the flange surface 107 is an outward facing surface (e.g., facing the second side portion 105) of the flange 130. The one or more mounting holes 135 may be defined in the flange surface 107, where the mounting holes 135 extend through the flange surface 107. The flange surface 107 extends around the second side portion 105 and is defined between an outer circumference of the second side portion 105 and an outer circumference of the body portion 103. When the inline duct fan 100 is mounted within ductwork, said ductwork may be connected to the second side portion 105 of the inline duct fan 100, where the second side portion 105 may be at least partially disposed within the ductwork. An outer surface (e.g., external surface) of the ductwork may rest on the flange surface 107 of the inline duct fan. In some embodiments, the ductwork may be fastened to the inline duct fan 100 via the mounting holes 135 on the flange 130. In some embodiments, the HVAC device 120 may be fastened to the inline duct fan 100 via the mounting holes 135.

Referring to FIGS. 4D-4E, the shroud 131 may define one or more mounting openings 138. The mounting openings 138 of the shroud 131 may extend through a side surface 137 of the shroud 131. The side surface 137 may be positioned to at least partially cover the flange 130 and/or the flange surface 107 of the body portion 103 (see FIGS. 4C and 5A). For example, the side surface 137 may extend from an outer circumference of the shroud 131 to the second side portion 105. For example, the inline duct fan 100 may be mounted to ductwork (e.g., flat sided ductwork) using a fastener insert through the mounting openings 138 of the shroud 131. When the inline duct fan 100 is mounted to ductwork, the ductwork may extend around the second side portion 105 and the ductwork (e.g., a surface thereof) may rest on the side surface 137 of the shroud 131. The shroud 131 may include one or more cutouts 139 positioned adjacent to the mounting openings 138, where the cutouts 139 at least partially extend into the shroud 131. The cutouts 139 provide for a fastener to be inserted into the mounting openings 138 for mounting the inline duct fan 100. In some embodiments, the mounting openings 138 of the shroud 131 may be spaced to align with the mounting holes 135 on the flange 130 of the body portion 103 (e.g., where a fastener may be inserted through the mounting holes 135 and the mounting openings 138 to couple the ductwork to the inline duct fan 100).

Referring to FIGS. 7A-7C, the inline duct fan 100 may be connected to an HVAC device 120 (e.g., a humidifier), where the inline duct fan 100 is configured for the second side portion 105 to be connected to the HVAC device 120. In some embodiments, the second side portion 105 of the inline duct fan 100 includes a fastener 122 (e.g., screw, bolt and nut, latch, clamp, adhesive, tape, keyed cam/lock, spring pin and ball feature, etc.) for attachment of the HVAC device 120 to the inline duct fan 100. For example, in some embodiments, the HVAC device 120 may be coupled to the inline duct fan 100 via the mounting holes 135 and/or the fastener 122. The HVAC device 120 (e.g., a mounting portion thereof) extends around the second side portion 105 to align with the fastener 122, so the fastener 122 may connect (e.g., fasten) the HVAC device 120 to the second side portion 105 of the inline duct fan 100. For example, the fastener 122 may be inserted into an opening (e.g., a hole) defined in the second side portion 105 for securing the HVAC device 120 to the inline duct fan 100. The HVAC device 120 may include a mounting opening (e.g., a hole) positioned corresponding to the fastener 122 when the HVAC device 120 is connected to the second side portion 105 of the inline duct fan 100. The fastener 122 may be inserted through the mounting opening of the HVAC device 120 and into the opening defined in the second side portion 105 to connect the HVAC device 120 to the inline duct fan 100. In some embodiments, the fastener 122 may create and/or define the opening in the second side portion 105 by tightening the fastener 122 (e.g., the fastener 122 may be a screw that drives through the second side portion 105 the first time the fastener 122 is used). For another example, the fastener 122 may be tightened and/or applied to secure the HVAC device 120, where the fastener 122 tightens against an external surface of the second side portion 105 (e.g., where the fastener 122 clamps the HVAC device 120 to the second side portion 105 to create a friction fit). The inline duct fan 100 may include additional fasteners positioned around the second side portion 105. In some embodiments, the HVAC device 120 may extend to the flange surface 107 to connect the HVAC device 120 to the inline duct fan 100 using the mounting holes 135, similar to connecting the inline duct fan 100 to the ductwork, as described herein. In some embodiment, the inline duct fan 100 may be connected to the ductwork using the fastener 122 (e.g., the ductwork may fit around the second side portion 105, similar to mounting of the HVAC device 120, as described herein).

Referring to FIGS. 9A and 9B, the inline duct fan 100 is variably mounted within the HVAC system, according to multiple HVAC system configurations. The first side portion 104 is connected to ductwork (e.g., a bypass duct), fitted around the first side portion 104 and extending up to the mounting tab 160 of the first side portion 104 (e.g., and/or at least partially underneath the mounting tab 160, etc.) . The ductwork may be connected to the first side portion 104 using adhesives and/or other attachment methods (e.g., fasteners). With reference to FIG. 9A, the second side portion 105 is disposed within ductwork (e.g., a return/supply air duct), where the outer surface of the ductwork rests on the side surface 137 of the shroud 131. In some embodiments, the outer surface of the ductwork may rest on the flange surface 107 of the body portion 103. The inline duct fan 100 in mounted (e.g., using a fastener) to the ductwork via the mounting holes 135 of the housing 102 and/or the mounting openings 138 of the shroud 131. With reference to FIG. 9B, the second side portion 105 is connected to the HVAC device 120. The second side portion 105 may be mounted to the HVAC device 120 via the fastener 122 (see FIGS. 7A-7B) and/or the mounting holes 135.

The second side portion 105 including the mounting holes 135 of the housing 102 provides for variable mounting of the inline duct fan 100, where the second side portion 105 may mount to ductwork and/or to the HVAC device 120 via the mounting holes 135. Furthermore, and/or in addition to, the second side portion 105 including the mounting holes 135 of the housing 102 and/or the mounting openings 138 of the shroud 131 provides for variable mounting of the inline duct fan 100, where the second side portion 105 may mount to ductwork and/or to the HVAC device 120 via the mounting holes 135. Therefore, the inline duct fan 100 may be mounted within the HVAC system according to limitations and/or optimization of said HVAC system so the inline duct fan 100 may move air throughout the HVAC system. Furthermore, the inline duct fan 100 including the first side portion 104 and the second side portion 105 configured to be partially disposed within ductwork and/or the HVAC device 120 minimizes the profile of the inline duct fan 100 when installed. Minimizing the profile of the inline duct fan 100 saves space, which may be necessary when space is limited when installing the inline duct fan 100 into the HVAC system.

Referring to FIGS. 1 through 6, the housing 102 of the inline duct fan 100 is generally cylindrical. The body portion 103, the first side portion 104, and/or the second side portion 105 may be generally cylindrical. The body portion 103, the first side portion 104, and/or the second side portion 105 may include chamfered, squared, or otherwise altered edges. The shroud 131 may correspond to the shape of the body portion 103 (e.g., the shroud 131 may be generally cylindrical when the body portion 103 is generally cylindrical). A width of the body portion 103 of the housing 102 may be larger than a width of the first side portion 104 and/or a width of the second side portion 105. In some embodiments, the width of the second side portion 105 is larger than a width of the first side portion 104. For example, the width of the first side portion 104 may be smaller to accommodate ductwork being fit around the outside of the first side portion 104, where the width of the second side portion 105 is sized to accommodate both mounting to an HVAC device 120 (e.g., where the second side portion 105 is sized to match the width of ductwork which is inserted into the HVAC device 120) and insertion into ductwork (e.g., via cutting a hole into said ductwork). In some embodiments, the body portion 103, the first side portion 104, and/or the second side portion 105 may define an interior volume thereof. The housing 102 of the inline duct fan 100 be integrally formed. The housing 102 of the inline duct fan 100 and/or the portions thereof may be formed using injection molding, 3D-printing, and/or other known manufacturing techniques. The portions of the housing 102 may be separately formed and assembled together. The housing 102 of the inline duct fan 100 may be assembled together using fasteners (e.g., screws), adhesives, press-fits, snap-fits, welding, and/or a combination thereof. Other assembly methods may be used.

Referring to FIG. 2A, the fan assembly 110 includes a fan blade 111 and a fan motor 112 (e.g., an electric motor) for operating the fan blade 111 to move air. In some embodiments, the fan assembly 110 may include multiple fan blades. The fan assembly 110 may be configured to move air through the ductwork.

The fan assembly 110 is positioned within the housing 102 in a manner such that the fan assembly 110 is offset relative to the central point 115 (e.g., central axis, central plane) within the inline duct fan 100. For example, the fan assembly 110 is offset from the central point 115 so the fan assembly 110 is extends into the first side portion 104. The body portion 103 of the housing includes a mounting surface 116 positioned within the interior volume of the housing 102, where the fan assembly 110 may be mounted at or near the central point 115. In some embodiments, the mounting surface 116 may be an inner surface of the body portion 103. In some embodiments, the mounting surface 116 may be positioned on an interior wall portion 118 (e.g., a wall, a bracket) extending within the interior volume of the housing 102 for mounting the fan assembly 110. The wall portion 118 is positioned at or near the central point 115.

Referring to FIGS. 2A, 4C, 6, and 7C, the inline duct fan 100 may further include a fan guard 114. The fan guard 114 is positioned within the housing 102 of the inline duct fan 100 adjacent to the fan assembly 110 toward the second side portion 105. The fan guard 114 may be connected to the housing 102 and/or the fan assembly 110. In some embodiments, the housing 102 may include the fan guard 114 (e.g., the wall portion 118 and/or the fan guard 114 may be components manufactured and/or assembled with the housing 102). The fan guard 114 may be fastened to the fan assembly 110 (e.g., to a non-rotational part of the fan assembly 110 as to not interfere with the fan blade 111). The fan guard 114 protects the fan assembly 110 from external interference (e.g., a user’s hand, debris), for example, when servicing the HVAC device 120 when attached to the inline duct fan 100. The fan guard 114 may improve the safety of the inline duct fan 100. In some embodiments, the fan guard 114 is removable. For example, the fan guard 114 may be removed from the inline duct fan 100 depending on the mounting configuration of the inline duct fan 100. In some embodiments, a damper blade 124 (see FIG. 7C) may be positioned within the ductwork, where the damper blade 124 is partially positioned within the second side portion 105 of the inline duct fan 100. The positioning of the damper blade 124 within the second side portion 105 provides clearance between the damper blade 124 and the fan assembly 110. The fan guard 114 may be positioned between the fan assembly 110 and the damper blade 124.

With reference to FIGS. 7B-7C, the inline duct fan 100 is connected to the HVAC device 120, where the HVAC device 120 is a humidifier including a damper blade 124. The damper blade 124 is positioned at least partially within the second side portion 105 of the inline duct fan 100. The positioning of the damper blade 124 within the second side portion 105 provides clearance between the damper blade 124 and the fan assembly 110 of the inline duct fan 100. The damper blade 124 may be used to control (e.g., partially limit) the airflow through the HVAC device 120. In some embodiments, when the second side portion 105 of the inline duct fan 100 is connected to the HVAC device 120, the first side portion 104 of the inline duct fan 100 may be mounted to the ductwork. The inline duct fan 100 is configured to move air from the HVAC device 120 through the ductwork and/or from the ductwork through the HVAC device 120.

Referring to FIGS. 4C and 7A, the second side portion 105 of the inline duct fan 100 includes a plurality of indentations 126 (e.g., grooves). The plurality of indentations 126 are configured to receive a plurality of fingers 128 (e.g., protrusions) included on the HVAC device 120 (e.g., on a mounting portion thereof) for attaching the HVAC device 120 to the inline duct fan 100. For example, mating of the plurality of fingers 128 within the plurality of indentations 126 secures the HVAC device 120 to the inline duct fan 100, including to secure the inline duct fan 100 in a set position (e.g., for easy access to controls of the HVAC device or the HVAC device, easy orientation of the HVAC device 120, simplify installation) and/or to lessen the effects of vibrations and/or other forces that may cause the fastener 122 (and/or other fasteners) to loosen and destabilize mounting of the inline duct fan 100. In some embodiments, the plurality of indentations 126 are spaced corresponding to spacing of the plurality of fingers 128. The number of fingers of the plurality of fingers 128 may be equal to the number of indentations of the plurality of indentations 126. In some embodiments, there may be more indentations than fingers, where not every indentation of the plurality of indentations receives a finger. The inline duct fan 100 configured with more indentations provides for flexible mounting with different HVAC devices and/or embodiments of the HVAC device 120.

In some embodiments, the inline duct fan 100 is installed concurrently with the HVAC system. In some embodiments, the inline duct fan 100 may be retrofitted into the HVAC system (e.g., an existing HVAC system). Mounting the inline duct fan 100 within the ductwork may involve forming openings in the ductwork and/or separating individual sections of ductwork from each other. Mounting the inline duct fan 100 may be completed using known assembly and/or disassembly methods (e.g., cutting). In some embodiments, the inline duct fan 100 is configured to be mounted within the HVAC system using the ductwork and/or the HVAC device 120, without the need for mounting to the HVAC system using additional support structures.

With reference to FIGS. 1, 2B, 4A-4B, and 10, the ductwork may include a first duct 201 and a second duct 202. In some embodiments, the first side portion 104 of the inline duct fan 100 is positioned within the first duct 201 of the HVAC system, wherein the first duct 201 extends to the mounting tab 160 of the first side portion 104 (e.g., and/or at least partially underneath the mounting tab 160, etc.) of the inline duct fan 100. For example, an opening of the first duct 201 may be fit around a perimeter of the first side portion 104. The first duct 201 may be a bypass duct, where the bypass duct is connected to the HVAC device 120 (e.g., the humidifier). In some embodiments, the first duct 201 (e.g., the bypass duct) may be connected to a third duct 203.

The second side portion 105 of the inline duct fan 100 is positioned within the second duct 202 of the HVAC system. In some embodiments, the body portion 103 of the housing 102 rests on an outer surface of the second duct 202 when the body portion 103 (e.g., the flange 130) is fastened to the second duct 202. The flange surface 107 may rest on the outer surface of the second duct 202. The body portion 103 of the housing 102 may be fastened to the second duct 202 using fasteners (e.g., screws, bolts) via the mounting holes 135 of the housing 102 and/or the mounting openings 138 of the shroud 131. For example, an opening may be formed in (e.g., cut into) the second duct 202 for positioning of the inline duct fan 100. In some embodiments, the inline duct fan 100 is configured to be interchangeably mounted (e.g., reversible) within the ductwork. For example, the first side portion 104 may be mounted to the second duct 202 and the second side portion 105 may be mounted to the first duct 201. The first side portion 104 may be mounted similarly to the second side portion 105, as described herein. In some embodiments, the ductwork may be circularly shaped and/or rectangularly shaped (e.g., a cross-section thereof may be circular and/or rectangular). The inline duct fan 100 may be connected to the ductwork (e.g., the first duct 201, the second duct 202, the third duct 203) where the ductwork is circularly shaped and/or rectangularly shaped, as described herein.

Referring to FIG. 10, the inline duct fan 100 is configured to move air in multiple directions, depending on the desired operation and/or configuration of the HVAC system. In some embodiments, the second duct 202 may be either a supply air duct and/or a return air duct. The third duct 203 may also be either the supply air duct and/or the return air duct, where the first duct 201 (e.g., the bypass duct) connects the return air duct and the supply air duct. The HVAC device 120 may be connected to the third duct 203, where the inline duct fan 100 may facilitate moving air from the second duct 202 (e.g., the supply air duct) through the first duct 201 (e.g., the bypass duct) and the HVAC device 120 for the air to be treated by the HVAC device 120, and then move the air into the third duct 203 (e.g., the return air duct) for circulation.

In some embodiments, the inline duct fan 100 may be mounted between multiple bypass ducts. The inline duct fan 100 may be mounted between the first duct 201 configured as a first bypass duct connected to an HVAC device 120 and a second bypass duct connected to the second duct 202. The first bypass duct and the second bypass duct may be fit around the outer perimeters of the first side portion 104 and the second side portion 105 of the inline duct fan 100. The inline duct fan 100 may be mounted in different HVAC system configurations (e.g., where the HVAC device 120 is mounted on different ducts, where the inline duct fan 100 is connected to the HVAC device 120) to move air throughout the HVAC system, as described herein. The inline duct fan 100 mounted within the ductwork reduces air turbulence and noise, while improving airflow within the ductwork. For example, turbulence and noise is reduced when the first side portion 104 of the inline duct fan 100 is at least partially disposed within the first duct 201. For another example, the inline duct fan 100 may minimally impede airflow through the second duct 202, while increasing airflow through the first duct 201 (e.g., the bypass duct).

Referring to FIGS. 8A-8C, the inline duct fan further includes processing circuitry 150 positioned within the housing 102 and configured to control the inline duct fan 100. The processing circuitry 150 is positioned on the body portion 103 of the housing 102, where the shroud 131 covers the processing circuitry 150. The processing circuitry 150 may be fastened to the body portion 103. The shroud 131 may include an access hatch 141 to provide access to the processing circuitry 150 contained underneath the shroud 131 (e.g., to perform maintenance, to troubleshoot, to install, etc.). The shroud 131 may include one or more buttons 142 (see FIGS. 1 and 4B) configured to be used for operation (e.g., operating changes, troubleshooting, fault clearing, etc.) of the inline duct fan 100. For example, the shroud 131 may include a power button, a reset button, and/or a configuration button. The one or more buttons 142 may extend from the body portion 103 through the shroud 131 (e.g., to an external surface of the shroud 131 for interaction by a user). In some embodiments, the shroud 131 may include an indicator for indicating a status and/or operation (e.g., on/off, operation mode, error) of the inline duct fan 100. The indicator may be a light configured to change colors for indicating the status and/or operation of the inline duct fan 100. The indicator may be connected to the processing circuitry 150. In some embodiments, the shroud 131 may include one or more connection elements (e.g., ports) and/or openings defined in the body portion 103 for the processing circuitry 150 to be connecting the processing circuitry 150 to external devices (e.g., power source(s), the HVAC device 120) from the inline duct fan 100. Wiring may extend from the connection elements and/or openings for connecting the processing circuitry 150. In some embodiments, the body portion 103 may include one or more of the components of the shroud 131 (e.g., the buttons, indicator, ports), as described herein. The components positioned on the body portion 103 may extend through the shroud 131 (e.g., of an opening thereof).

In some embodiments, the inline duct fan 100 may include absorbing material (e.g., sound absorbing material) positioned underneath the shroud 131. The body portion 103 of the housing 102 may include one or more perforations (e.g., holes, slits) defined in the housing 102 for sound to be absorbed (e.g., from the fan assembly operating) into the absorbing material underneath the shroud 131.

With reference to FIGS. 8A-8C, the processing circuitry 150 includes a first controller 151 configured to operate the fan motor 112 of the fan assembly 110. The first controller 151 is positioned on the surface 133 of the body portion 103 underneath the shroud 131 of the inline duct fan 100. The processing circuitry 150 further includes a second controller 152 communicably coupled to the first controller 151 and configured to control operation of the inline duct fan 100. The second controller 152 is positioned opposite the first controller 151 along a circumference of the surface 133 of the body portion 103 of the inline duct fan 100. For example, the second controller 152 may be positioned on an opposite side of the fan assembly 110 from the first controller 151. The first controller 151 and the second controller 152 being positioned opposite each other along the circumference of the surface 133 of the body portion 103 may increase the performance of the inline duct fan 100, as the controller positioning avoids interfering with airflow through the inline duct fan 100. Further, the controller positioning provides for a compact profile of the inline duct fan 100, which may decrease the weight of the inline duct fan 100 and increase mounting flexibility. And using multiple controllers may improve maintenance capability and operational flexibility of the inline duct fan 100.

The second controller 152 is communicably coupled to external devices (e.g., to a controller of the HVAC system such as a thermostat or a humidistat) to the inline duct fan 100 for controlling the inline duct fan 100 within the HVAC system. In some embodiments, the second controller 152 may be wirelessly to external devices (e.g., via a WI-FI connection). For example, the second controller 152 is used to determine when and/or how to operate the inline duct fan 100 for providing air through the ductwork, while the first controller 151 controls the fan assembly 110 to move said air accordingly. In some embodiments, the one or more buttons 142 may be connected to the second controller 152, where the one or more buttons 142 may be used to manually control the inline duct fan 100 using the second controller 152. In some embodiments, the inline duct fan 100 further includes a sensor communicably coupled to the second controller 152, where the sensor is positioned within the ductwork of the HVAC system. The sensor may be positioned within the first duct 201 (e.g., the bypass duct) to detect one or more properties of the air and send sensor data indicative of said properties of the air to the second controller 152 for determining an operation of the inline duct fan 100 (e.g., to use the fan assembly 110 to move air into the bypass duct). The properties of the air may include one or more of air temperature, air humidity, air speed or flow rate, and/or other properties. In some embodiments, the inline duct fan 100 may be used as a sensor, where the processing circuitry 150 creates sensor data based on the operation of the inline duct fan 100 (e.g., based on a rotation of the fan blade 111).

HVAC System

In some embodiments, a system 300 including the inline duct fan may be configured with various HVAC devices. For example, the system 300 may include a dehumidifier, a humidifier, a heat exchanger, an air filter, and/or other HVAC devices. Referring to FIGS. 10-11D, the system 300 is configured as a bypass humidification system. The system 300 includes an HVAC device 120, configured as a humidifier 320, coupled to ductwork to humidify air. The system 300 further includes an inline duct fan 100 positioned between the ductwork and the humidifier 320, where the inline duct fan 100 is configured to move air from the ductwork through the humidifier 320 for providing humidified air within the system 300.

Still referring to FIGS. 10-11D, the ductwork includes a first duct 201, a second duct 202, and a third duct 203, where the first duct 201 is configured as a bypass duct 301, the second duct 202 is configured as a supply air duct 302, and the third duct is configured as a return air duct 303. For example, the supply air duct 302 may be a conduit for treated air (e.g., humidified, heated) through the system 300 (e.g., an HVAC system of a building), where the return air duct 303 returns the air within the system 300 for treatment (e.g., humidification, heating). The system 300 may further include a heat exchanger 321 positioned between the return air duct 303 and the supply air duct 302. The heat exchanger 321 is configured to treat (e.g., heat, cool) the air within the ductwork to provide treated air throughout the system 300.

The bypass duct 301 connects the supply air duct 302 to the return air duct 303 through the humidifier 320, where the humidifier 320 is connected to the bypass duct 301 and/or the inline duct fan 100. The bypass humidification components (e.g., the humidifier 320, the inline duct fan 100, the bypass duct 301, etc.) may be positioned above the heat exchanger 321. Other configurations of the system 300 may be used (e.g., different heating elements, additional HVAC components, different installation arrangements based on installation requirements for the system within a building).

Referring to FIG. 11A, the humidifier 320 is mounted on and coupled to the return air duct 303 and the inline duct fan 100 is connected to the humidifier 320 and the bypass duct 301. Referring to FIG. 11D, the inline duct fan 100 may be coupled to the supply air duct 302 and the bypass duct 301. The inline duct fan 100 is configured to move air from the supply air duct 302 through the bypass duct 301 and through the humidifier 320 for humidification and circulation of humidified air through the return air duct 303.

Referring to FIG. 11B, the humidifier 320 is mounted on and coupled to the supply air duct 302 and the inline duct fan 100 is connected to the return air duct 303 and the bypass duct 301. Referring to FIG. 11C, the inline duct fan 100 may be coupled to the bypass duct 301 and the humidifier 320. The inline duct fan 100 is configured to move humidified air from the humidifier 320 through the bypass duct 301 for circulating humidified air through the return air duct 303.In some embodiments, the system 300 may be mounted on one of the ducts (e.g., the supply air duct 302, the return air duct 303). For example, the humidifier 320 may be mounted on the supply air duct 302, where the inline duct fan 100 is connected to the bypass duct 301, where the bypass duct 301 connects back to the supply air duct 302. For another example, the inline duct fan 100 may be connected to the supply air duct 302, with the bypass duct 301 connecting the inline duct fan 100 and the humidifier 320 for providing humidity to air within the return air duct 303.

The inline duct fan 100 may be variably positioned within the system according to specific installation limitations and/or optimization for the system 300, as described herein. For example, the humidifier 320 may be mounted on the return air duct 303 due to space limitations with the supply air duct 302, thereby requiring mounting of the inline duct fan 100 between the humidifier 320 and the supply air duct 302. The system 300 is configured for the inline duct fan 100 to draw (e.g., move) heated air from the supply air duct 302 into the humidifier 320 for humidification, since heated air is more efficient for humidification, and circulate said humidified air into the return air duct 303 where the air in the return air duct 303 may be re-heated by the heat exchanger 321 so heated and humidified air may be circulated throughout the system 300.

Referring to FIG. 12, a method 400 of installation for an HVAC system is depicted. The method 400 may be used to install an embodiment of the inline duct fan 100 and/or the system 300, as disclosed herein. The method 400 may include additional, different, and/or a different order of method steps. In some embodiments, the method 400 of installation may be used to install the HVAC system in its entirety (e.g., when installing the ductwork and/or other components). For example, the method 400 may include installing ductwork and/or other HVAC components. In some embodiments, the method 400 may be used to install via retrofitting the bypass humidification components (e.g., inline duct fan 100, humidifier 320, bypass duct 301) to an existing HVAC system. The method 400 may include forming openings at connection points for connecting the inline duct fan 100 and/or the humidifier 320.

The method 400 includes connecting the first side portion of the inline duct fan to a first duct, at method step 410. The method 400 further includes connecting the second side portion of the inline duct fan to either of the second duct or the humidifier, at method step 420. The humidifier may be connected to the second duct. The method 400 further includes electrically connecting processing circuitry of the inline duct fan to the humidifier, wherein the inline duct fan operates to move air through the humidifier for humidification of air, at method step 430. In some embodiments, the method 400 may include mounting the humidifier to ductwork. The humidifier may be mounted on either the first duct and/or the second duct. The method 400 may be used to connect the first duct to the second duct through the humidifier for humidification of air. The inline duct fan increases the efficiency of humidifying the air by moving the air from the first duct and/or the second duct through the humidifier.

Control System

Referring to FIGS. 13A-13E, the system 300 further may include a controller 330. In some embodiments, the controller 330 is a controller 330 of an HVAC system. For example, the controller 330 may be a thermostat and/or a humidistat. The processing circuitry 150 is configured to receive data indicative of properties of air within the system 300. For example, the processing circuitry 150 may receive data indicative of air humidity and/or air temperature. In some embodiments, where the system 300 may be retrofitted onto an HVAC system (e.g., an existing system within a building), where the HVAC system is a closed-loop system, the system 300 may be controlled at least partially using inputs from the controller 330 (e.g., the controller of the HVAC system). For example, the system 300 may include the processing circuitry 150 (e.g., of the inline duct fan 100) for separate control of the system 300 from the controller of the HVAC system. The controller of the HVAC system is communicably coupled to the processing circuitry 150 of the system 300 (e.g., for bypass humidification), where the processing circuitry 150 may receive sensor data from the controller. The sensor data is indicative of properties of air within the system. In some embodiments, the bypass humidification components are installed concurrently with the HVAC system. The processing circuitry 150 may receive sensor data indicative of properties of the air (e.g., air humidity, air temperature) within the system 300 from a sensor, where the system 300 includes the sensor (e.g., the sensor of the inline duct fan 100) disposed within the ductwork of the system 300. The system 300 is at least partially controlled using inputs from components of the system 300.

In some embodiments, the processing circuitry 150 is communicably coupled to the inline duct fan 100 and the humidifier 320. The processing circuitry 150 is configured to receive a command for operating the humidifier 320, and operate the humidifier 320, based on the command, to humidify the air within the system 300. The processing circuitry 150 is further configured to operate the inline duct fan 100, based on the command, to move air through the humidifier 320. The command may be a signal sent by a user (e.g., resident) requesting humidification. The command may be a signal sent by the controller 330 of the HVAC system requesting humidification. For example, the controller 330 of the HVAC system may determine that humidification is desired by comparing a measured air humidity to an air humidity set point, and then send the signal, where the processing circuitry 150 of the system 300 receives the signal and thereby controls the bypass humidification components to complete the humidification request.

In some embodiments, the processing circuitry 150 is configured to receive sensor data indicative of a property of air within the system, compare the sensor data to a corresponding setpoint, and operate the humidifier 320, based on comparing the sensor data to the corresponding setpoint, to humidify air within the system 300. The processing circuitry 150 is further configured to operate the inline duct fan 100 to move air through the humidifier 320. In some embodiments, the sensor data may be indicative of one or more of air temperature and/or air humidity. The processing circuitry 150 may determine (e.g., calculate) the property of the air based on the sensor data. The corresponding setpoint may be an air temperature setpoint and/or an air humidity setpoint. Multiple corresponding setpoints may be used depending on the sensor data received from the sensor. The corresponding setpoint may be a threshold value (e.g., maximum, minimum) and/or a range of values. In some embodiments, the inline duct fan 100 may be used as a sensor, where the processing circuitry 150 creates sensor data based on the operation of the inline duct fan 100. For example, the processing circuitry 150 may be configured to determine properties of the air and/or airflow through the system 300 based on a rotation of the fan blade 111 and/or other performance metrics of the inline duct fan 100. By determining the airflow based on the rotation of the fan blade 111 (e.g., the performance of the inline duct fan 100), the inline duct fan 100 may be operated to modify the airflow through the system 300 (e.g., increase airflow to increase air humidity by moving more air through the humidifier 320).

To connect the processing circuitry 150 throughout the system to control the bypass humidification components, electrical connections may be formed. The electrical connections may be formed using electrical wires and/or known electrical connection methods. The bypass humidification components may also be electrically connected to a primary power source. Referring to FIGS. 13A and 13B, a first electrical connection 341 is formed between the controller 330 of the HVAC system and a transformer 332 (e.g., a secondary power source). A second electrical connection 342 is formed between the transformer 332 and the humidifier 320. A third electrical connection 343 is formed between the humidifier 320 and the inline duct fan 100 (e.g., with the processing circuitry 150 thereof). A fourth electrical connection 344 is formed between the inline duct fan 100 and the controller 330 of the HVAC system.

In some embodiments, the transformer 332 is a 24V power source. In some embodiments, the second electrical connection 342 is between an electrical control valve on the humidifier 320 and the transformer 332, where the electrical control valve is used to complete the circuit when humidification is requested and/or determined for the system 300. The third electrical connection 343 may be between the electrical control valve of the humidifier 320 and the inline duct fan 100, so the inline duct fan 100 may be operated when the electrical control valve completes the circuit to complete the humidification request and/or determination. The processing circuitry 150 may control the electrical control valve to complete the circuit for providing humidification through the system 300.

In some embodiments, the humidifier 320 is communicably coupled to the controller 330 through the inline duct fan 100. For example, operation of the inline duct fan 100 (e.g., turning on) is the signal for the humidifier 320 to be operated, so the humidifier 320 is operated corresponding to the inline duct fan 100 (e.g., so the humidifier runs when the inline duct fan is turned on). The processing circuitry 150 of the inline duct fan 100 is configured to receive sensor data indicative of a property of air within the system and compare the sensor data to a corresponding setpoint. The processing circuitry 150 is further configured to operate the inline duct fan 100, based on comparing the sensor data to the corresponding setpoint, to operate the inline duct fan 100 for providing air through the humidifier 320, and operate the humidifier 320, based on operating the inline duct fan 100, to humidify air within the HVAC system.

Referring to FIGS. 13C and 13D, to connect the processing circuitry 150 of the inline duct fan 100 throughout the system 300 for controlling the humidifier 320 through the inline duct fan 100, electrical connections are formed. In some embodiments, a first electrical connection 351 is formed between the controller 330 of the HVAC system and the transformer 332. A second electrical connection 352 is formed between the transformer 332 and the inline duct fan 100. A third electrical connection 353 is formed between the inline duct fan 100 and the controller 330. A fourth electrical connection 354 is formed between the transformer 332 and the humidifier 320. A fifth electrical connection 355 is formed between the humidifier 320 and the inline duct fan 100. A sixth electrical connection 356 is formed between the inline duct fan 100 and the transformer 332. In some embodiments, where the bypass humidification components are retrofitted into an existing HVAC system, one or more of the electrical connections may be formed by splicing into existing electrical connections (e.g., wires).

In some embodiments, the fifth electrical connection 355 is between the electrical control valve on the humidifier 320 and the inline duct fan 100, where the electrical control valve is used to complete the circuit when humidification is requested and/or determined for the system 300. The processing circuitry 150 of the inline duct fan 100 may control the electrical control valve based on the processing circuitry 150 controlling the inline duct fan 100. The inline duct fan 100 is directly connected to the transformer 332 (e.g., using the second electrical connection 352 and the sixth electrical connection 356), providing control of the system 300 using the inline duct fan 100. For example, the circuit is completed by controlling the electronic control valve to control the humidifier 320 based on the operation of the inline duct fan 100, instead of relaying a command for humidification from the controller 330 of the HVAC system to the inline duct fan 100 (e.g., the processing circuitry 150 of the inline duct fan 100 is operably controlling the system 300, so the controller 330 of the HVAC system is an input to the processing circuitry 150). Operating the system 300 through the inline duct fan 100 also provides the user (e.g., a homeowner) control to manually request and/or command humidification, where the humidifier 320 will be operated based on the inline duct fan 100 operating.

Referring to FIG. 13E, the system 300 may include the inline duct fan 100 configured to operate in response to humidified air and/or operation from the humidifier 320. According to such an embodiment, the inline duct fan 100 may not be connected to an external device (e.g., controller 330 such as a thermostat or humidistat). For example, the inline duct fan 100 may be connected to a power source (e.g., a 120V outlet). The processing circuitry 150 of the inline duct fan 100 is configured to monitor the air within the system 300 (e.g., using a humidity sensor, temperature sensor, or other air data sensor) to determine when the humidifier 320 is operating, so the inline duct fan 100 may be operated accordingly. The sensor may be disposed within the system 300 (e.g., within the ductwork, within the inline duct fan 100). For example, if the inline duct fan 100 is not communicably coupled to the system 300, the processing circuitry 150 may be configured to determine a property of the air (e.g., humidity, temperature), and operate the inline duct fan 100 to modify airflow in the system 300 (e.g., through the humidifier 320) accordingly. For example, the processing circuitry 150 may receive sensor data indicative of a property of the air (e.g., humidity, temperature) and determine, based on the sensor data, a change in the property of the air over time. For example, the change in the property of air over time (e.g., a ramp up or ramp down of humidity or temperature or an end to such a ramp up or ramp down) may be indicative of an HVAC command (e.g., heating command, humidification command, cooling command) and/or an end to an HVAC cycle. For example, the processing circuitry 150 may determine when the HVAC system is calling for (e.g., signaling, requesting) an HVAC operation, such as humidification of air using the humidifier 320, so the inline duct fan 100 may be operated accordingly (e.g., to move air through the humidifier 320 to increase output of humidified air, to shut off after a humidification cycle is complete). For example, the inline duct fan 100 may operate independent of or without control signals directly from the HVAC system (e.g., without control signals from the controller 330), such as in a plug-and-go mode, where the inline duct fan 100 operates without connection to external devices (e.g., the controller 330) of the HVAC system (e.g., an existing system within a building).

Referring to FIG. 17B, the inline duct fan 100 may be electrically connected within the HVAC system 1100 (e.g., to adjust airflow therein). For example, a fourth electrical connection 1154 may be between the inline duct fan 100 and a first electrical connection point 1161. The inline duct fan 100 may be electrically connected to the humidifier 320 via the fourth electrical connection 1154 and a first portion of the first electrical connection 1151a, through the first electrical connection point 1161. By forming the fourth electrical connection 1154 and the first electrical connection point 1161, the first electrical connection 1151 may include the first portion of the first electrical connection 1151a from the humidifier 320 to the first electrical connection point 1161, and a second portion of the first electrical connection 1151b from the first electrical connection point 1161 to the transformer 332 (e.g., so the humidifier 320 may be powered by the transformer 332). The inline duct fan 100 is electrically connected to the transformer 332 (e.g., to receive power thereby) via the second portion of the first electrical connection 1151b and the fourth electrical connection 1154, through the first electrical connection point 1161.

A fifth electrical connection point 1155 may be between the inline duct fan 100 and a second electrical connection point 1162. The inline duct fan 100 may be coupled (e.g., electrically, communicably) to the HVAC controller 1120 via the fifth electrical connection point 1155 and a first portion of the third electrical connection 1153a, through the second electrical connection point 1162. By forming the fifth electrical connection point 1155 and the second electrical connection point 1162, the third electrical connection 1153 may include the first portion of the third electrical connection 1153a, and a second portion of the third electrical connection 1153b from the second electrical connection point 1162 to the humidifier 320 (e.g., so the humidifier 320 is and/or remains coupled to the HVAC controller 1120).

Operating the inline duct fan 100 may be completed using various parameters, including rotations per minute (RPM). RPMs of the inline duct fan 100 may be indicative of airflow within the system (e.g., greater RPMs equates to greater airflow). RPMs of the inline duct fan 100 may be controlled by controlling the fan motor 112 of the fan assembly 110 (e.g., change the fan motor 112 speed). In some embodiments, the inline duct fan 100 may be configured to operate in various modes and/or states, where each mode or state corresponds to operational configurations. The operations of the inline duct fan 100 for each mode or state may be stored in memory of the processing circuitry 150. The operation of the inline duct fan 100 is further based on sensor data indicative of properties of the air, as described herein.

In some embodiments, the inline duct fan 100 may be controlled in a first state (e.g., starting state), where the inline duct fan 100 awaits controlling (e.g., a base state where the system 300 is not in use to provide bypass humidification). In some embodiments, the inline duct fan 100 may be controlled in a second state, where the inline duct fan 100 has an increased RPM compared to the first state (e.g., an operational RPM for providing air to the humidifier 320). For example, the inline duct fan 100 may have RPMs increased when the processing circuitry 150 determines humidification is desired. The inline duct fan 100 may be configured in various states and/or modes (e.g., a third state, a fourth state) depending on the properties of the air within the system 300. For example, the inline duct fan 100 may be operated differently depending on the air humidity and/or air temperature when the inline duct fan 100 is operated. The varying states may be programmed into the memory of the processing circuitry 150 for operation of the inline duct fan 100 accordingly.

In some embodiments, the inline duct fan 100 and/or the system 300 may be controlled based on additional aspects of the system 300 and/or the HVAC system. In some embodiments, the inline duct fan 100 and/or the system 300 may be used to correct over temperature faults. For example, an over temperature fault may occur due to recirculating air without humidifying, where the inline duct fan 100 may be used to change a pressure of the system 300 and/or serve as an air brake (e.g., lock and/or run the inline duct fan 100 in a reverse direction to a humidification direction). In some embodiments, the inline duct fan 100 and/or the system 300 may be used to determine a state of the HVAC system. For example, the inline duct fan 100 may be used as a sensor to determine airflow through the inline duct fan 100 (e.g., flow rate of air in the bypass duct 301, etc.). Based on the airflow, determine a pressure (e.g., a differential pressure, such as between the supply air duct 302 and the return air duct 303 relative to the bypass duct 301 connected therebetween, where in some embodiments the static pressure of the HVAC system 1100 may be determined based on the differential pressure of the bypass duct 301, etc.) of the HVAC system (e.g., for use in additional determinations, etc.). The inline duct fan 100 may be communicably coupled to the HVAC system, where operation of the inline duct fan 100 is an input for the HVAC system to determine an operation (e.g., optimal airflow, optimal air path, etc.). In some embodiments, the inline duct fan 100 and/or the system 300 may be used to control airflow through the HVAC system. For example, the inline duct fan 100 may be a sensor to determine airflow through the bypass duct, where the airflow is used by the HVAC system to determine the pressure of the HVAC system and/or change the pressure based on operation the system 300 and/or the HVAC system. In some embodiments, the inline duct fan 100 and/or the system 300 may be used to decrease buildup (e.g., moisture) within the humidifier 320 (e.g., on the panels/coils). For example, the inline duct fan 100 may be controlled to move air into the humidifier 320 to dry the humidifier 320. One or more sensors may be used to determine a moisture level within the humidifier 320, where the one or more sensors are communicably coupled to the processing circuitry 150 of the inline duct fan 100. The inline duct fan 100 may be programmed with a schedule for drying the humidifier 320 (e.g., at set times, at set intervals). In some embodiments, the inline duct fan 100 and/or the system 300 may be used to determine an ideal configuration of the HVAC system and/or the system 300. For example, the inline duct fan 100 may be operated to determine if the pressure of the HVAC system is desired and/or if the pressure or performance of the humidifier 320 is desired (e.g., to calibrate and/or test the operation of the HVAC system or the system 300). In some embodiments, the inline duct fan 100 and/or the system 300 may be used to reduce noise within the system 300. In some embodiments, the inline duct fan 100 and/or the system 300 may be used to maintain moisture within the humidifier 320 to prevent maintenance issues (e.g., hard water clogs). For example, the inline duct fan 100 may be operated at scheduled times to move wet air and/or moisture into the humidifier 320 to prevent drying. For another example, the inline duct fan 100 may be operated to activate (and/or deactivate) a solenoid water valve of the humidifier 320 to move (e.g., pulse) water into the humidifier 320 to prevent valve components from drying. In some embodiments, the inline duct fan 100 and/or the system 300 may be used as the sensor to perform maintenance checks on the humidifier 320 (e.g., determine if the humidifier 320 is operating as desired). For example, the inline duct fan 100 may be operated to obtain diagnostics and/or check for proper component function of the components within the system 300 (e.g., checking valve functions for proper water delivery via RH levels, panel clogging, end of life and/or other operational indicators configured within the system 300, etc.). The inline duct fan 100 and/or the system 300 may be operated and/or used in additional ways to the benefit of efficient and/or optimized HVAC devices or processes.

Method for Humidification

Referring to FIGS. 14-16, methods for humidifying air are depicted. The methods may be carried out by an embodiment of the system, as disclosed herein. The methods may include additional, different, and/or a different order of method steps.

Referring to FIG. 14, a method 500 for humidifying air includes receiving a command for operating a humidifier to humidify air, at method step 510. The method 500 further includes operating an inline duct fan, based on the command, to move air through the humidifier, at method step 520. The method 500 further includes operating the humidifier, based on the command, to humidify air, at method step 530. In some embodiments, the command may be sent from a user (e.g., resident, occupant). The user may send the command using a user device (e.g., HVAC controller, tablet, thermostat, etc.). For example, the command may be sent wirelessly (e.g., Bluetooth, WI-FI). In some embodiments, the command may be sent by an external controller (e.g., of an HVAC system) to request humidification.

Referring to FIG. 15, a method 600 for humidifying air includes receiving sensor data indicative of an air humidity, at method step 610. The method 600 further includes comparing the sensor data to an air humidity setpoint, at method 620. The method 600 further includes operating the humidifier and the inline duct fan, based on comparing the sensor data to the air humidity setpoint, to humidify air, at method step 630. In some embodiments, the sensor data may be indicative of other properties of air. For example, the sensor data may be indicative of air temperature. Thereby, the method 600 may include comparing the sensor data to an air temperature setpoint.

Referring to FIG. 16, a method 700 for humidifying air includes receiving sensor data indicative of an air humidity, at method step 710. The method 700 further includes comparing the sensor data to an air humidity setpoint, at method step 720. The method 700 further includes operating an inline duct fan, based on comparing the sensor data to the air humidity setpoint, to operate the inline duct fan for providing air to a humidifier, at method step 730. The method 700 further includes operating the humidifier, based on operating the inline duct fan, to humidify air, at method step 740. For example, the inline duct fan being turned on may be used to operate the humidifier, so the humidifier is operated when the inline duct fan is turned on. In some embodiments, the sensor data may be indicative of other properties of air. For example, the sensor data may be indicative of air temperature. Thereby, the method 700 may include comparing the sensor data to an air temperature setpoint.

Inline Duct Fan Control System

Referring to FIGS. 17A-24B, the inline duct fan may be operated through a plurality of operating modes to adjust airflow within the HVAC system, such as airflow through the humidifier and/or other HVAC device. For example, an HVAC device, such as the humidifier, may be fluidly coupled to a bypass duct of the HVAC system (e.g., a bypass humidifier configuration), where the inline duct fan adjusts airflow within the bypass duct and/or through the humidifier. Adjusting airflow to be within desired airflow conditions (e.g., increasing airflow as air is circulated and/or during other low-airflow events, decreasing airflow during high-airflow events, etc.), increases the performance of the humidifier and/or other HVAC device. Current implementations to adjust airflow through a humidifier include manually adjusting a position of the damper thereof. Once the position of the damper of the humidifier is set, the performance of the humidifier may decrease if the airflow conditions within the HVAC system are not desirable for humidification (e.g., zone dampers open, low air temperature, cooling command active, etc.). Thereby, the inline duct fan provides for adjustable airflow through the HVAC system, such as through the humidifier, so said airflow can be controlled while still providing desirable airflow for humidification and/or other air treatments.

For example, in one embodiment, the inline duct fan may include a fan controller communicably coupled to the fan assembly of the inline duct fan, where the fan controller is configured to operate the inline duct fan through the plurality of operating modes. The plurality of operating modes may include one or more of an initial mode in which the inline duct fan is activated in (e.g., the controller determines an operability of the inline duct fan in the initial mode, etc.), an idle mode in which the fan assembly passively rotates (e.g., while waiting to detect one or more HVAC commands), a dynamic mode in which the controller is configured to adjust a speed of the fan assembly based on airflow conditions through the inline duct fan, where inline duct fan transitions to the dynamic mode based on receiving a humidification command from an external controller, a block mode in which the fan assembly decreases airflow through the inline duct fan based on the airflow conditions, where the inline duct fan transitions to the block mode based on receiving either a temperature command (e.g., a heating command, a cooling command, etc.) or an air circulation command, and not receiving the humidification command, and an error mode in which the inline duct fan is configured to provide feedback indicative of a fault to a user, where the inline duct fan transitions to the error mode based on the inline duct fan experiencing a fault.

The inline duct fan, such as via the various operating modes thereof, may be configured for operation within a specific HVAC system that the inline duct fan is installed in. During installation, the inline duct fan may be manually controllable (e.g., by a contractor) to test operational performance of the inline duct fan. Based on testing the performance, configuring the inline duct fan may include, but is not limited to, setting a fan direction (e.g., clockwise, counterclockwise) based on the configuration of the HVAC system (e.g., where an HVAC device and/or the inline duct fan is positioned and/or mounted within ductwork, etc.), determining an airflow direction (e.g., based on the fan direction), and/or adjusting speeds (e.g., setting predetermined speeds, etc.) for the fan assembly of the inline duct fan, as described herein. For example, one or more inputs (e.g., buttons, switches, etc.) may be provided (e.g., adjusted, set, etc., such as by the contractor) to configure the inline duct fan (e.g., the fan direction, mounting position, fan speeds, etc.).

The fan controller may store data received from the fan assembly (e.g., a fan motor thereof), where the data is indicative of operational parameters of the fan assembly. The fan controller, based on one or more of the data indicative of the operational parameters of the fan assembly, sensor data received from sensors disposed within the HVAC system, data received from the HVAC controller and/or other external inputs (e.g., user input), determines and/or adjusts operation of the inline duct fan, such as a speed of the fan assembly, based on variable environmental (e.g., airflow, temperature, etc.) conditions within the HVAC system. Thereby, the inline duct fan may adjust airflow with variable airflow (e.g., air speed) HVAC systems, increase output on heat pump systems, and/or limit entrainment within HVAC high-pressure systems. Adjusting the speed of the inline duct fan controls airflow to be substantially within desired limits of HVAC devices, such as bypass humidifiers, that operate based on pressure differentials and/or available airflow from ductwork within HVAC systems. By adjusting airflow to be within desired airflow conditions (e.g., increasing airflow as air is circulated and/or during other low-airflow events, decreasing airflow during high-airflow events, etc.), the inline duct fan increases the performance of the humidifier and/or other HVAC device and/or decreases HVAC risks due to uncontrolled airflow (e.g., leaks, noise, faults, etc.).

For example, the inline duct fan increases the delivery (e.g., airflow) of treated air (e.g., humidified air, etc.) throughout a building (e.g., a residence and/or a living space thereof, etc.). The inline duct fan improves airflow in low static pressure HVAC systems, where, for example, HVAC devices such as bypass humidifiers operate with poor performance (e.g., provide under-humidified air, waste of water due to poor efficiency). By providing the inline duct fan into the HVAC system, the inline duct fan increases airflow to compensate for low pressure within the HVAC system, thereby increasing air treatment performance by the HVAC device.

For another example, the inline duct fan may control airflow within the HVAC system, such that the inline duct fan blocks and/or brakes the flow of air. The inline duct fan may operate at a reduced speed (e.g., less than a freewheeling speed of the inline duct fan within the HVAC system) to restrict airflow through the inline duct fan. Thereby, the inline duct fan reduces damage risks to HVAC devices within the HVAC system due to high airflows and/or decreases leaks and/or entrainment or re-entrainment (e.g., decreasing risks due to excess airflow in high pressure environments). For yet another example, the inline duct fan provides for a damper of the HVAC device (e.g., a humidifier damper) to be kept open. Thereby, the inline duct fan can operate as a damper for the HVAC system (e.g., the HVAC device thereof, such as a humidifier), thereby reducing the necessity of controlling and/or setting dampers within said HVAC system.

Referring to FIGS. 17A-17B, the inline duct fan 100 is at least partially controlled based on various inputs, such as signals (e.g., HVAC commands, signals indicative of environmental conditions, etc.) and/or determinations indicative of conditions (e.g., air and/or environmental conditions, etc.) within an HVAC system 1100. For example, the inline duct fan 100 (e.g., the fan controller 1020 thereof) may be communicably coupled to an external controller. The fan controller 1020 may be communicably coupled to an HVAC controller 1120 (e.g., a thermostat, a humidistat, etc.), such that the inline duct fan 100 receives signals from the HVAC controller 1120. For example, the signals from the HVAC controller 1120 may be indicative of HVAC commands within the HVAC system 1100 (e.g., control signals to one or more HVAC devices 1110, such as the humidifier 320, the heat exchanger 321, etc.). Based on the signals (e.g., HVAC commands), the inline duct fan 100 may be operated via a plurality of operating modes 1200 to adjust airflow within the HVAC system 1100. For example, each operating mode of the plurality of operating modes 1200 corresponds to a desired adjustment to the airflow within the HVAC system 1100.

Referring to FIG. 17B, the fan controller 1020 may include the first controller 151 and/or the second controller 152. For example, the first controller 151 may be configured to control the fan assembly 110 (e.g., a speed thereof). The second controller 152 may be communicably coupled to the HVAC controller 1120 (e.g., to receive data and/or HVAC commands therefrom). The second controller 152 may be configured to determine one or more control operations for the inline duct fan 100 (e.g., an operating mode for the inline duct fan 100, speed for the fan assembly 110, etc.). The second controller 152 may transmit one or more control signals, based on determining the one or more control operations, to the first controller 151, where the first controller 151 controls the fan assembly 110 based on the one or more control signals.

In some embodiments, for example, as shown in FIGS. 11A-11D, the HVAC system 1100 may include, but is not limited to including, one or more HVAC devices 1110 (e.g., the HVAC device 120, the humidifier 320, the heat exchanger 321, an HVAC fan 1105, etc.), ductwork (e.g., the bypass duct 301, the supply air duct 302, the return air duct 303, etc.), the inline duct fan 100, and/or the HVAC controller 1120. For example, the HVAC system 1100 may be an embodiment of an HVAC system, as described herein. In some embodiments, the HVAC controller 1120 may be and/or be similar to the controller 330. For example, the HVAC device 120 (e.g., the humidifier 320, etc.) may be fluidly coupled to the bypass duct 301 of the HVAC system 1100, where the inline duct fan adjusts airflow within the bypass duct 301 and/or through the HVAC device 120 (e.g., the humidifier 320).

Referring to FIGS. 17B and 18, the inline duct fan 100 may operate in a first operating mode, where the inline duct fan 100 is initiated (e.g., is powered on and/or reset, loads operating programs and/or applications stored in the memory of the fan controller 1020, performs system checks to determine operability and/or condition of the inline duct fan 100, etc.). For example, as shown in FIG. 18, the first operating mode may be an initial mode 1201 of the inline duct fan 100 (e.g., a startup mode). The inline duct fan 100 may move to (e.g., enter, change to, transition to, etc.) the initial mode 1201 when powered on (e.g., started, etc.). In the initial mode 1201, the fan controller 1020 may configure the inline duct fan 100 for operation. For example, configuring the inline duct fan 100 for operation in the initial mode 1201 may include, but is not limited to, determining operability of inline duct fan 100 components (e.g., fan motor 112, first controller 151, etc., such that these components are not experiencing a fault), determining compatibility (e.g., communication) with the HVAC controller 1120, determining and/or configuring (e.g., setting, controlling) a fan direction (e.g., rotational direction, airflow direction) of the inline duct fan 100, and/or determining and/or configuring one or more operating parameters for the inline duct fan 100 (e.g., fan speed, fan acceleration or deceleration, fan acceleration and/or deceleration time, etc.). Once the inline duct fan 100 is configured, the fan controller 1020 may move the inline duct fan 100 from the initial mode 1201 to a second operating mode.

In the second operating mode, the inline duct fan 100 is configured to passively operate, (e.g., provide for the fan blade 111 to freewheel and/or be inactive, based on the airflow within the HVAC system 1100, await and/or monitor for signals from the HVAC controller 1120, monitor environmental conditions within the HVAC system 1100 such as via a sensor, etc.). For example, as shown in FIG. 18, the second operating mode may be an idle mode 1202 of the inline duct fan 100 (e.g., an inactive mode, a passive mode). For example, in the idle mode 1202, the inline duct fan 100 is not actively controlled. In the idle mode 1202, the fan controller 1020 may passively operate, such that the fan controller 1020 awaits (e.g., monitors for) a signal for airflow and/or air treatment (e.g., an HVAC command) from the HVAC system 1100 (e.g., the HVAC controller 330, the HVAC controller 1120, etc.). For example, in the idle mode 1202, the fan controller 1020 may not receive a signal from the HVAC system 1100 indicative of an HVAC command (e.g., there may not be an HVAC command, such as an air treatment command, such as a humidification command, a heating command, a cooling command, etc.), so the fan blade 111 of the inline duct fan 100 may freewheel to maintain and/or monitor current airflow (e.g., flow rate of air, pressure, temperature, and/or humidity, etc.) within the HVAC system 1100. Thereby, when the inline duct fan 100 is in the idle mode 1202, the current environmental (e.g., airflow) conditions of the HVAC system 1100 are substantially maintained and/or the fan controller 1020 continually monitors the airflow conditions within the HVAC system 1100 (e.g., within the bypass duct 301 thereof, through the HVAC device 120, etc.).

In some embodiments, in the idle mode 1202 the inline duct fan 100 may analyze the airflow within the HVAC system 1100 and/or perform system checks. For example, the inline duct fan 100 may determine if the fan motor 112 is turned off (e.g., so the fan blade 111 may rotate passively), determine a system voltage to determine a presence of an error within the inline duct fan 100 (e.g., to check that the inline duct fan 100 is operating correctly), and/or configure the inline duct fan 100 to set an operational parameter, such as a fan direction (e.g., clockwise, counterclockwise) and/or a fan speed (e.g., rotational velocity) for the inline duct fan 100. In some embodiments, the inline duct fan 100 may determine airflow conditions, such as flow rate (e.g., volumetric flow rate), velocity, pressure, temperature, and/or humidity, based on data from the fan assembly 110 (e.g., rotational direction of the fan blade 111, rotational speed/velocity of the fan blade 111, and/or changes thereof over time). For example, the fan assembly 110 (e.g., the fan motor 112) may transmit data (e.g., fan data) to the fan controller 1020, where the fan controller 1020 may determine airflow conditions for the air flowing through the inline duct fan 100 (e.g., indicative of air within the HVAC system 1100). Based on the airflow conditions, the fan controller 1020 may adjust operational parameters of the inline duct fan 100 when the inline duct fan 100 is operational, as described herein, so the inline duct fan 100 may adjust airflow within the HVAC system 1100. For example, adjusting airflow may provide benefits for increasing and/or decreasing humidification via airflow through the humidifier 320, limiting sound from the HVAC system 1100, and/or adjusting air pressure within the HVAC system 1100, such as a differential pressure (e.g., between the supply air duct 302 and the return air duct 303 relative to the bypass duct 301 connected therebetween, etc.).

Referring to FIG. 18, the inline duct fan 100 may receive (e.g., detect) one or more signals indicative of one or more HVAC commands from the HVAC controller 1120. For example, the one or more HVAC commands may be, but are not limited to, a humidification command (e.g., to increase air humidity within the HVAC system 1100, such as by operation of the humidifier 320), and/or a temperature command (e.g., to increase and/or decrease air temperature, such as by operation of the heat exchanger 321). Based on the presence of the one or more HVAC commands from the HVAC controller 1120, the inline duct fan 100 may move between the various operating modes. For example, when the inline duct fan 100 is in the idle mode 1202, if the inline duct fan 100 receives a signal indicative of a humidification command from the HVAC system 1100, the inline duct fan 100 may move to a third operating mode. As shown in FIG. 18, the third operating mode may be a dynamic mode 1203.

In the dynamic mode 1203, the inline duct fan 100 is configured to adjust airflow (e.g., increase, decrease, change a direction of rotation for the fan assembly 110, etc.) within the HVAC system 1100, such as through the bypass duct 301 and/or the humidifier 320. For example, a flow rate (e.g., baseline flow rate) of air provided by an HVAC fan 1105 (e.g., a central fan of the HVAC system 1100 for moving air from the heat exchanger 321 throughout the HVAC system 1100) through the bypass duct 301 of the HVAC system 1100, due to differential pressure across the bypass duct 301, may be 100 cubic feet per minute (CFM). As airflow within the HVAC system 1100 varies (e.g., through the bypass duct 301, such as due to changing differential pressure, etc.) adjusting the airflow via the inline duct fan 100 adjusts (e.g., increases, decreases, changes a direction of rotation for the fan assembly 110, etc.) the performance of the humidifier 320 for humidification of the air within the HVAC system 1100. To adjust the airflow, the speed of the fan assembly 110 (e.g., the fan blade 111, the fan motor 112) may be adjusted. For example, the speed of the fan assembly 110 may be adjusted (e.g., set) by the fan controller 1020, based on the airflow conditions proximate to when the humidification command is received by the inline duct fan 100. The airflow conditions may include a flow rate of air and/or an air pressure (e.g., within the HVAC system 1100, through or within the inline duct fan 100). The airflow conditions may be determined by the fan controller 1020, based on a first speed of the fan assembly 110 (e.g., an initial speed, such as a passive speed when the fan blade 111 freewheels when in the idle mode 1202, etc.). For example, the first speed of the fan assembly 110 may be the fan speed responsive to the fan assembly 110 passively rotating due to the airflow within the HVAC system 1100 (e.g., airflow conditions as the humidification command is received by the inline duct fan 100). Based on the airflow conditions, the fan controller 1020 may determine a second speed (e.g., adjusted speed, desired speed, a boost speed) of the fan assembly 110, where the fan controller 1020 adjusts the fan speed of the fan assembly 110 to the second speed (e.g., adjusted from the first speed). For example, in the dynamic mode 1203 the second speed of the fan assembly 110 may be greater than the first speed of the fan assembly 110 (e.g., when boosting airflow) and/or less than the first speed of the fan assembly 110 (e.g., when braking airflow).

The second speed of the fan assembly 110 may cause the airflow conditions to be adjusted (e.g., increased or decreased flow rate of air and/or an air pressure, etc.) to provide desirable airflow conditions (e.g., flow rate of air and/or air pressure, etc.) through the inline duct fan 100. For example, in the dynamic mode 1203, adjusting the airflow condition to be desirable airflow conditions may include increasing the flow rate of air when the HVAC system 1100 (e.g., the bypass duct 301 thereof) has a low static air pressure (e.g., as determined by the fan controller 1020 via the first speed of the fan assembly 110), as unadjusted airflow conditions may cause decreased air humidification performance due to the low static air pressure (e.g., because low static pressure causes insufficient airflow through the humidifier 320, reducing humidification output and/or humidifier efficiency, and/or wasting water to humidify the air). By causing desirable airflow conditions by operating the inline duct fan 100 in the dynamic mode 1203, the air humidification performance of the humidifier 320 may be increased (e.g., increased humidification output when the HVAC system 1100 has a low static air pressure).

In some embodiments, when the inline duct fan 100 is in the dynamic mode 1203, the pressure within the HVAC system 1100 may increase (e.g., spike) due to an external event (e.g., zone damper closing, flow rate of air increasing during a temperature command to increase air temperature, etc.). In some embodiments, based on the airflow conditions, the fan controller 1020 may determine the second speed (e.g., adjusted speed, desired speed, a brake speed) of the fan assembly 110, where the fan controller 1020 adjusts the fan speed of the fan assembly 110 to the second speed (e.g., adjusted from the first speed). For example, in the dynamic mode 1203 the second speed of the fan assembly 110 may be less than the first speed of the fan assembly 110 (e.g., when the second speed is the brake speed). By adjusting the inline duct fan 100 to the brake speed, airflow within the HVAC system 1100 (e.g., the bypass duct 301 thereof) is within a desirable airflow range to decrease airflow through the one or more HVAC devices 1110 (e.g., the humidifier 320) thereof (e.g., desired airflow range provides for evaporation of moisture in the air without causing water droplets to entrain into the air, such that the brake speed restricts airflow so the damper blade 124 of the humidifier 320 may be positioned in a substantially open position, and/or reducing risks of leaks due to excess airflow in high pressure conditions, which may cause entrainment, etc.).

In some embodiments, the speed of the fan assembly 110 may be adjusted by the fan controller 1020, based on one or more of the one or more signals indicative of the one or more HVAC commands received by the fan controller 1020 (e.g., a temperature command to increase the air temperature, a temperature command to decrease the air temperature, etc.). In some embodiments, the fan controller 1020 may determine a type of temperature command (e.g., heat command, cool command) and/or determine if the temperature command or the air circulation command is active, based on air temperature. For example, the fan controller 1020 may receive sensor data indicative of air temperature from one or more sensor disposed within the ductwork of the HVAC system 1100. When the air temperature is greater than or equal to a heating command threshold, the temperature command may be indicative of increasing the air temperature (e.g., heating the air). For example, the heating command threshold may be approximately 85 degrees Fahrenheit. When the air temperature is less than or equal to a cooling command threshold, the temperature command may be indicative of decreasing the air temperature (e.g., cooling the air). For example, the cooling command threshold may be approximately 55 degrees Fahrenheit.

In some embodiments, when in the dynamic mode 1203, the speed of the fan assembly 110 may be adjusted based on the temperature command being active (e.g., detected and/or received by the fan controller 1020). In some embodiments, the fan controller 1020 may determine the air temperature based on receiving sensor data indicative of said air temperature (e.g., from one or more sensor disposed within the ductwork of the HVAC system 1100). In some embodiments, the fan controller 1020 may determine the air temperature based on operational parameters of the fan assembly 110 and/or data received by the HVAC controller 1120 (e.g., by measuring a relative airflow through the bypass duct 301 and/or the inline duct fan 100 compared to the supply air duct 302 and/or the return air duct 303, and/or compared to airflow provided by the HVAC fan 1105, etc.). In some embodiments, the inline duct fan 100 may be electrically connected to the HVAC fan 1105 and/or the HVAC controller 1120 (e.g., W/Y/G terminals thereof).

In some embodiments, when the temperature command is indicative of an increase in air temperature (e.g., a heat command), the HVAC system 1100 may increase airflow (e.g., the flow rate of air) (e.g., to effectively deliver heat throughout the HVAC system 1100 and/or the building said system provides airflow for). During the temperature command to increase air temperature, the speed of the inline duct fan 100 may be adjusted to a maximum speed (e.g., a sound threshold speed, since sound levels may be favorable for high-speed operation during air temperature increases by the HVAC system 1100). In some embodiments, such as where the air circulation command is active, the speed of the inline duct fan 100 is decreased (e.g., compared to the maximum speed, where a sound threshold is lower during the air circulation command compared to the temperature command, so a lower speed for the inline duct fan 100 reduces sound disturbances during operation).

In some embodiments, the speed of the fan assembly 110 may be adjusted by the fan controller 1020, based on HVAC system parameters and/or fault thresholds, including, but not limited to, a size (e.g., width, volume, etc.) of the ducts, performance capacity of the heat exchanger 321 and/or a central fan of the HVAC system 1100 (e.g., to move the air throughout the HVAC system 1100), system materials, external environmental conditions (e.g., temperature, humidity, etc.), the HVAC device 120 (e.g., the humidifier 320) performance parameters and/or fault thresholds, and/or user preferences. For example, the speed of the fan assembly 110 may be adjusted by the fan controller 1020, based on a fault threshold, such as an entrainment threshold and/or a sound threshold. The speed of the fan assembly 110 may be adjusted to provide airflow such that the HVAC system 1100 and/or the HVAC device 120 thereof (e.g., the humidifier 320) operates above, below, and/or within the fault threshold (e.g., so the HVAC system 1100 and/or the HVAC device 120 thereof does not enter entrainment and/or cause sound disturbances due to the airflow therein). In some embodiments, the speed of the fan assembly 110 may be adjusted by the fan controller 1020, based on multiple factors (e.g., parameters), as described herein.

The inline duct fan 100 may be in the dynamic mode 1203 for a duration of the humidification command. In some embodiments, the humidification command may be approximately a 24-volt signal. When the humidification command ends, the fan controller 1020 may move the inline duct fan 100 into the idle mode 1202. For example, when in the dynamic mode 1203, if the fan controller 1020 does not receive (e.g., stops receiving) the humidification command, the inline duct fan 100 may move into the idle mode 1202.

Referring to FIG. 18, when the inline duct fan 100 is in the idle mode 1202, if the inline duct fan 100 receives (e.g., detects) a signal indicative of a temperature command (e.g., to increase and/or decrease air temperature) from the HVAC system 1100, the inline duct fan 100 may move to a fourth operating mode. As shown in FIG. 18, the fourth operating mode may be a block mode 1204. For example, the inline duct fan 100 may move to the block mode 1204 based on receiving the temperature command, and not receiving the humidification command.

In the block mode 1204, the inline duct fan 100 is configured to adjust airflow (e.g., decrease) within the HVAC system 1100, such as through the bypass duct 301 and/or the humidifier 320. For example, by adjusting airflow, HVAC components, such as the humidifier 320 and/or the heat exchanger 321, are protected from damage due to over-circulation of treated air within the HVAC system 1100 (e.g., faults due to high air temperatures, due to low air temperatures, damage causing suboptimal humidifier 320 performance, etc.), as airflow through the HVAC system 1100 (e.g., the bypass duct 301 thereof) is controlled by the inline duct fan 100 in the block mode 1204.

In the block mode 1204, to adjust the airflow, the speed of the fan assembly 110 (e.g., the fan blade 111, the fan motor 112) may be adjusted. For example, the speed of the fan assembly 110 may be adjusted (e.g., set) by the fan controller 1020, based on the airflow conditions proximate to when the temperature command is received by the inline duct fan 100 (e.g., an active block mode). The airflow conditions may include a flow rate of air and/or air pressure (e.g., within the HVAC system 1100, through or within the inline duct fan 100). The airflow conditions may be determined by the fan controller 1020, based on the first speed of the fan assembly 110 (e.g., an initial speed, such as a passive speed when the fan blade 111 freewheels when in the idle mode 1202, etc.). For example, the first speed of the fan assembly 110 may be the fan speed responsive to the fan assembly 110 passively rotating due to the airflow within the HVAC system 1100 (e.g., airflow conditions as the temperature command is received by the inline duct fan 100). Based on the airflow conditions, the fan controller 1020 may determine the second speed (e.g., adjusted speed, desired speed) of the fan assembly 110, where the fan controller 1020 adjusts the fan speed of the fan assembly 110 to the second speed (e.g., adjusted from the first speed). For example, in the block mode 1204, the second speed of the fan assembly 110 may be less than the first speed of the fan assembly 110. In some embodiments, the second speed of the fan assembly 110 may be greater than or equal to the first speed of the fan assembly 110 (e.g., where adjusting speed of the fan assembly 110 includes changing the direction of rotation of the fan assembly 110, such that the first speed and the second speed may be in different directions). The second speed of the fan assembly 110 may cause the airflow conditions to be adjusted (e.g., increased or decreased a flow rate of air and/or air pressure, etc.) to provide desirable airflow conditions (e.g., flow rate of air and/or air pressure, etc.) within the inline duct fan 100. For example, in the block mode 1204, adjusting the airflow condition to be desirable airflow conditions may include decreasing the flow rate of air (e.g., by blocking airflow) when the HVAC system 1100 has a high flow rate of air (e.g., as determined by the fan controller 1020 via the first speed of the fan assembly 110) and/or a high pressure within at least a portion of the HVAC system 1100 (e.g., a high differential pressure across the bypass duct 301, such that the flow rate of air through the bypass duct 301 is high, etc.), as unadjusted airflow conditions may cause damage to HVAC components, such as the humidifier 320 and/or the fan assembly 110 of the inline duct fan 100 due to high air velocities. By causing desirable airflow conditions by operating the inline duct fan 100 in the block mode 1204, protection from damage is increased for components within the HVAC system 1100, such as the humidifier 320 (e.g., high and/or low temperature faults, etc.).

In some embodiments, when the inline duct fan 100 is in the idle mode 1202, if the inline duct fan 100 receives (e.g., detects) a signal indicative of an air circulation command (e.g., to operate the HVAC fan 1105 of the HVAC system 1100 to circulate air therein) from the HVAC system 1100, the inline duct fan 100 may move into the block mode 1204. In the block mode 1204, the fan assembly 110 of the inline duct fan 100 may passively operate (e.g., a passive block mode). For example, if the air temperature is within (e.g., and/or above or below) a temperature threshold, the inline duct fan 100 may passively resist (e.g., block) airflow in the block mode 1204. The fan blade 111 may rotate (e.g., freewheel, such that the fan motor 112 may be powered off) to passively block airflow through the HVAC system 1100. When the HVAC command is the air circulation command, and not the temperature command, the air within the HVAC system 1100 can flow through HVAC components within the HVAC system 1100 (e.g., the humidifier 320) without a substantial risk to damage for said components. By passively blocking the air, wear and tear to the inline duct fan 100 (e.g., the fan assembly 110 thereof) is decreased, while achieving a controlled airflow in the block mode 1204.

In some embodiments, the speed of the fan assembly 110 may be adjusted by the fan controller 1020, based on an air temperature of air within the HVAC system 1100. For example, the inline duct fan 100 may include a temperature sensor to determine the air temperature. In some embodiments, the fan controller 1020 may receive the air temperature from the HVAC controller 330. Based on the air temperature and/or the temperature command, the fan controller 1020 may determine if the airflow conditions (e.g, the air temperature) exceed a temperature fault threshold (e.g., may cause damage to the humidifier 320). If the temperature fault threshold is exceeded, the fan speed is adjusted to adjust (e.g., decrease, block, etc.) the airflow within the HVAC system 1100, for example, where the inline duct fan 100 is in the block mode 1204.

In some embodiments, the speed of the fan assembly 110 may be adjusted by the fan controller 1020, based on HVAC system parameters and/or fault thresholds, including, but not limited to, a size (e.g., width, volume, etc.) of the ducts, performance capacity of the heat exchanger 321 and/or a central fan of the HVAC system 1100 (e.g., to move the air throughout the HVAC system 1100), system materials, external environmental conditions (e.g., temperature, humidity, etc.), the HVAC device 120 (e.g., the humidifier 320) performance parameters and/or fault thresholds, and/or user preferences. For example, the speed of the fan assembly 110 may be adjusted by the fan controller 1020, based on a fault threshold, such as an entrainment threshold and/or a sound threshold. The speed of the fan assembly 110 may be adjusted to provide airflow such that the HVAC system 1100 operates above, below, and/or within the fault threshold (e.g., so the HVAC device 120 does not enter entrainment and/or cause sound disturbances due to the airflow therein). In some embodiments, the speed of the fan assembly 110 may be adjusted by the fan controller 1020, based on multiple factors (e.g., parameters), as described herein.

The inline duct fan 100 may be in the block mode 1204 for a duration of the temperature command and/or the air circulation command. When the temperature command and/or the air circulation command ends, the fan controller 1020 may move the inline duct fan 100 into the idle mode 1202. For example, when in the block mode 1204, if the fan controller 1020 does not receive (e.g., stops receiving) the temperature command, the inline duct fan 100 may move into the idle mode 1202. In some embodiments, the inline duct fan 100 may move from the block mode 1204 to the idle mode 1202 based on receiving the humidification command from the HVAC system 1100 (e.g., from the HVAC controller 1120 thereof, where the inline duct fan 100 may move from the idle mode 1202 to the dynamic mode 1203, based on the humidification command).

As shown in FIG. 18, if the inline duct fan 100 experiences a fault, the inline duct fan 100 may move to a fifth operating mode, shown as the error mode 1205. For example, if the fan controller 1020 determines a presence of the fault in the inline duct fan 100, the fan controller 1020 moves the inline duct fan 100 into the error mode 1205. For example, when the inline duct fan 100 is in the initial mode 1201, the inline duct fan 100 may experience the fault in an event of, but not limited to, the fan controller 1020 (e.g., the first controller 151, the second controller 152, etc.) failing to initiate (e.g., failing to load software, communicably incompatible with HVAC system 1100 and/or components thereof, etc.), the fan controller 1020 failing to configure the inline duct fan 100 (e.g., failing to set the operational parameters thereof, etc.), and/or the fan controller 1020 determining a fault within a component of the inline duct fan 100 (e.g., the fan motor 112, etc.). For another example, when the inline duct fan 100 is in the idle mode 1202, the inline duct fan 100 may experience the fault in an event of, but not limited to, determining a low-power (e.g., voltage) being supplied to the inline duct fan 100 from a power supply (e.g., the supplied voltage is less than a minimum voltage threshold to power the inline duct fan 100, etc.), the fan assembly 110 (e.g., the fan motor 112 thereof) failing to deactivate (e.g., does not turn off and/or the speed of the fan assembly 110 does not adjust, etc.), airflow conditions failing to meet expected airflow conditions, such as exceeding threshold values (e.g., air temperature over, under, and/or outside of an air temperature threshold or threshold range, air pressure in the bypass duct 301 greater than a safe air pressure threshold, etc.), operational parameters failing to meet expected operational parameter values, such as exceeding threshold values, and/or stalling of the fan assembly 110.

Referring to FIGS. 20A-20B, when the inline duct fan 100 enters (e.g., changes to) the dynamic mode 1203, the speed of the fan assembly 110 may be a first speed (e.g., an initial speed), where the fan controller 1020 determines and/or adjusts (e.g., sets) the speed of the fan assembly 110 to a second speed (e.g., a boost speed, a brake speed). For example, the speed of the fan assembly 110 may be the boost speed to increase (e.g, boost) airflow within the HVAC system 1100 (e.g., through the humidifier 320, etc.), and/or the brake speed to decrease (e.g., brake) airflow through the HVAC system 1100 (e.g., the humidifier 320, etc.). In some embodiments, the boost speed and/or the brake speed refers to the speed of the fan assembly 110 in the fan direction (e.g., direction of rotation of the fan assembly 110) causing airflow in substantially the same direction as the airflow within the HVAC system 1100. In some embodiments, the brake speed for the fan assembly 110 may refer to the fan direction of the fan assembly 110 causing airflow opposite the airflow direction (e.g., decreasing the airflow) within the HVAC system 1100, such as through the HVAC device 120 (e.g., the humidifier 320).

The speed of the fan assembly 110 may be determined (e.g., determining the second speed) and/or adjusted (e.g., setting the speed to the second speed) by the fan controller 1020 based on one or more of the environmental conditions (e.g., current airflow conditions) of the HVAC system 1100, HVAC commands, and/or current operating parameters of the inline duct fan 100 (e.g., current supplied to the fan motor 112, torque of the fan motor 112, speed of the fan assembly 110, etc.). Thereby, by dynamically adjusting the speed of the inline duct fan 100, airflow conditions within the HVAC system 1100, such as airflow through the HVAC device 120 (e.g., the humidifier 320) thereof, are adjusted to improve the performance of the HVAC device 120 (e.g., the humidifier 320).

When in the dynamic mode 1203, the speed of the fan assembly 110 may vary between a plurality of speed values, as determined and/or set by the fan controller 1020, based on the airflow (e.g, environmental conditions and/or HVAC commands within the HVAC system 1100. The speed of the fan assembly 110 may be a first dynamic mode speed, such as a sound threshold speed 1301 (e.g., a maximum speed as to not exceed a sound threshold), when the flow rate of air within the HVAC system 1100 does not exceed an airflow threshold 1302. For example, the airflow threshold 1302 may be a flow rate threshold for the air within the HVAC system 1100 (e.g., a maximum flow rate for the air, etc.). For another example, the airflow threshold 1302 may be an air pressure threshold (e.g., a low-pressure threshold, a high-pressure threshold, a pressure threshold range, a pressure differential threshold, etc.). In some embodiments, the airflow threshold 1302 defines operational and/or desirable pressures for the HVAC system 1100 (e.g., where said airflow won’t cause low-pressure faults, high-pressure faults, and/or pressure differential faults within the HVAC system 1100, such as entrainment, etc.). For example, the airflow threshold 1302 may define the maximum flow rate of air where said airflow provides for operational air pressure within the HVAC system 1100. The sound threshold speed 1301 may be less than or equal to a sound threshold 1303 (e.g., noise limit) for airflow within the HVAC system 1100. For example, the sound threshold speed 1301 is a maximum speed that does not exceed the sound threshold 1303. Thereby, when operating at the sound threshold speed 1301, the inline duct fan 100 does not exceed the sound threshold 1303 (e.g., so the inline duct fan 100 does not make unwanted noise to disturb a user of the HVAC system 1100, such as a resident, tenant, occupant, etc.). For example, the speed of the fan assembly 110 may be the sound threshold speed 1301 when airflow within the HVAC system 1100 is desirable (e.g., the air has a high static air pressure, the HVAC command is a high heat command, airflow is at a constant speed, etc.).

In some embodiments, for example, where airflow within the HVAC system 1100 is variable (e.g., where entrainment may be an issue for the humidifier 320, for example, due to high differential pressure across the bypass duct 301, etc.), the speed of the fan assembly 110 may be determined and/or adjusted (e.g., set) by the fan controller 1020. When in the dynamic mode 1203, the speed of the fan assembly 110 may be a variable speed (e.g., dynamic, such as where the speed of the fan assembly 110 may boost and/or brake airflow at least partially through the HVAC system 1100). For example, the speed of the fan assembly 110 may be determined and/or set by the fan controller 1020 based on one or more of the environmental conditions (e.g., current airflow conditions) of the HVAC system 1100, HVAC commands, and/or current operating parameters of the inline duct fan 100. As the airflow conditions within the HVAC system 1100 vary, the airflow conditions (e.g., pressure) may exceed the airflow threshold 1302 (e.g., too high of air pressure within the HVAC system 1100), where the speed of the fan assembly 110 of the inline duct fan 100 is adjustable to adjust the airflow conditions within the HVAC system 1100 so the adjusted airflow conditions do not exceed the airflow threshold 1302 (e.g., for safe operation of the humidifier 320 and/or other HVAC device, to avoid entrainment within the HVAC system 1100, etc.). By using the dynamic mode 1203, determining and/or adjusting the speed of the fan assembly 110 of the inline duct fan 100 controls airflow within the HVAC system 1100 as to not exceed the airflow threshold 1302. Thereby, dynamically controlling the speed of the inline duct fan 100 provides for the inline duct fan 100 to be installed within various HVAC systems having different and/or variable configurations, for example, due to static pressures, airflow speeds, duct configurations (e.g., zoning and/or positions of zone dampers, and/or faulty ducts), and/or damper configurations.

In some embodiments, the fan controller 1020 is communicably coupled to one or more sensors configured to detect the airflow conditions within the HVAC system 1100 (e.g., disposed at least partially within the ducts thereof), where the fan controller 1020 receives sensor data from one or more sensors indicative of the airflow conditions within the HVAC system 1100. Based on the sensor data, the fan controller 1020 may determine and/or set the speed of the fan assembly 110 of the inline duct fan 100 to adjust airflow within the HVAC system 1100.

In some embodiments, the fan controller 1020 determines airflow conditions (e.g., and/or changes thereof, such as over a time period), such as air pressure, within the HVAC system 1100 based on operational parameters of the inline duct fan 100, such as the fan assembly 110 thereof (e.g., thereby the fan controller 1020 may determine air pressure without direct pressure sensing via one or more sensors disposed throughout the HVAC system 1100). For example, the operational parameters of the inline duct fan 100 may include, but are not limited to, a current of the fan motor 112, a voltage supplied to and/or a back electromotive force (BEMF) applied on the fan motor 112, a torque of the fan assembly 110 (e.g., the fan blade 111 and/or the fan motor 112 thereof, etc.), and/or the speed of the fan assembly 110 (e.g., the fan blade 111 and/or the fan motor 112 thereof, etc.).

Referring to FIGS. 19 and 20A-20B, a process 2000 (e.g., a method) of adjusting airflow within an HVAC system is illustrated. The process 2000 may be completed (e.g., carried out) with an embodiment of the inline duct fan 100, as described herein. In some embodiment, the process 2000 may be used to adjust airflow within an embodiment of the HVAC system 1100, as described herein. In some embodiments, the process 2000 may include additional, fewer, and/or a different order of steps (e.g., operations). For example, as shown in FIGS. 20A-20B, the speed of the fan assembly 110 of the inline duct fan 100 may be determined and/or adjusted (e.g., set) based on the process 2000 (e.g., dynamically determining the second speed when in the dynamic mode 1203 to adjust airflow). For example, the fan controller 1020 may complete (e.g, carry out) the process 2000. When the inline duct fan 100 enters (e.g., changes to, transitions to, etc.) the dynamic mode 1203, the fan controller 1020 may initiate the process 2000.

Referring to FIG. 19, the process 2000 may include determining a first dynamic mode speed (e.g., initial dynamic speed) of the fan assembly (e.g., when the inline duct fan 100 is in the dynamic mode 1203), at operation 2010. For example, in some embodiments, the process 2000 may include determining if a humidification command is active (e.g., receiving and/or detecting said command), where based on the humidification command, the inline duct fan enters a dynamic mode to adjust the speed of the fan assembly. In some embodiments, the process 2000 includes determining the first dynamic mode speed based on a freewheeling speed of the fan assembly (e.g., if the fan assembly is freewheeling when the dynamic mode is entered, etc.). In some embodiments, the process 2000 may include determining the first dynamic speed based on a predicted airflow (e.g., predicted flow rate, predicted air pressure, etc.) through the HVAC system (e.g., the predicted airflow may be based on the freewheeling speed of the fan assembly, etc.).

Referring to FIGS. 20A-20B, when the inline duct fan 100 enters (e.g., changes to) the dynamic mode 1203, the speed of the fan assembly 110 may be the first speed (e.g., the initial speed). For example, the first speed may be a freewheeling speed 1310 (e.g., speed due to passive rotation of the fan blade 111 due to airflow through the inline duct fan 100, such that the fan blade 111 is not powered by the fan motor 112 when the fan blade 111 is freewheeling). In some embodiments, when the inline duct fan 100 enters the dynamic mode 1203, the HVAC system 1100 may be in an idle state. For example, the HVAC fan 1105 may be activated, based on the HVAC command (e.g., the temperature command, such as a heating command, and/or the humidification command, etc.). The fan controller 1020 may initiate a timer when the inline duct fan 100 enters the dynamic mode 1203. A time period for the HVAC fan 1105 to reach a steady state of operation (e.g., after activation thereof) may be provided by the fan controller 1020 (e.g., via the timer). For example, if the freewheeling speed 1310 of the fan assembly 110 is less than or equal to a minimum fan speed threshold minimum fan speed threshold for the speed of the inline duct fan 100 to be adjusted in the dynamic mode 1203, the fan controller 1020 may not adjust the speed of the fan assembly 110 until the time period ends (e.g. expires, runs out, etc.) and/or the freewheeling speed 1310 exceeds the minimum fan speed threshold minimum fan speed threshold. For example, the time period may be approximately 90 seconds. In some embodiments, the fan controller 1020 may adjust the speed of the fan assembly 110 before the time period ends and/or when the inline duct fan 100 enters the dynamic mode 1203, based on the freewheeling speed 1310 of the fan assembly 110 being greater than the minimum fan speed threshold minimum fan speed threshold for the speed of the inline duct fan 100 to be adjusted in the dynamic mode 1203 (e.g., where the HVAC fan 1105 has increased airflow through the HVAC system 1100, such that the fan assembly 110 freewheels above the minimum fan speed threshold, so the fan assembly 110 may be activated and/or the speed thereof may be adjusted).

Referring to FIGS. 20B, in some embodiments, the speed of the fan assembly 110 may be adjusted (e.g., set) by the fan controller 1020 to one of a plurality of predetermined speed values and/or ranges. For example, the plurality of predetermined speed values may be used to set the speed of the inline duct fan 100 when entering the dynamic mode 1203. In some embodiments, the plurality of predetermined speed values are based on parameters of the HVAC system 1100.

In some embodiments, if the freewheeling speed 1310 of the fan assembly 110 is less than or equal to the minimum speed threshold 1305 for adjusting the speed of the fan assembly 110 in the dynamic mode 1203, the fan controller 1020 may adjust the speed of the fan assembly 110 to be a second dynamic mode speed, such as an initial boost speed 1311 (e.g., one of the plurality of predetermined speed values). If the timer expires (e.g., the HVAC fan 1105 is operating in the steady state, where the speed of the fan assembly 110 is less than the minimum fan speed threshold minimum fan speed threshold), the fan controller 1020 may adjust the speed of the fan assembly 110 to be the initial boost speed 1311.

In some embodiments, when the speed of the fan assembly 110 is greater than or equal to the minimum fan speed threshold minimum fan speed threshold, the fan controller 1020 may compare the freewheeling speed 1310 of the fan assembly 110 to one or more dynamic mode speed thresholds to determine an adjusted speed of the fan assembly 110. For example, if the freewheeling speed 1310 of the fan assembly 110 is less than or equal to a first dynamic mode speed threshold 1321 (e.g., a first dynamic speed threshold), the fan controller 1020 adjusts the speed of the fan assembly 110 to be the initial boost speed 1311 (e.g., the second dynamic mode speed, 1700 RPMs, etc.). In some embodiments, the first dynamic mode speed threshold 1321 may be approximately 1700 RPMs.

In the dynamic mode 1203, if the first speed (e.g., the initial speed) of the fan assembly 110 is less than the initial boost speed 1311, the fan controller 1020 adjusts (e.g., increases) the speed of the fan assembly 110 to increase (e.g., boost) airflow within the HVAC system 1100, such as through the HVAC device 120 (e.g., the humidifier 320). In the dynamic mode 1203, the fan controller 1020 may determine when to decrease the speed of the fan assembly 110 to decrease (e.g., brake) airflow within the HVAC system 1100. For example, if the initial speed of the fan assembly 110 is greater than the initial boost speed 1311, the fan controller 1020 may adjust (e.g., decrease) the speed of the fan assembly 110 to decrease (e.g., brake) airflow within the HVAC system 1100, such as through the HVAC device 120 (e.g., the humidifier 320). In some embodiments, the fan controller 1020 may adjust (e.g., change, switch) the direction of rotation of the fan assembly 110 to decrease (e.g., brake) airflow within the HVAC system 1100 (e.g., within the bypass duct 301 thereof, through the HVAC device 120, etc.). For example, when the direction of rotation of the fan assembly 110 is adjusted, the speed of the fan assembly 110 may be increased to brake airflow (e.g., operating the fan assembly 110 faster, but in the opposite direction).

If the freewheeling speed 1310 of the fan assembly 110 is greater than the first dynamic mode speed threshold 1321 (e.g., and/or where the freewheeling speed 1310 is greater than the minimum speed threshold 1305) and/or less than or equal to a second dynamic mode speed threshold 1322 (e.g., a second dynamic speed threshold), the fan controller 1020 adjusts the speed of the fan assembly 110 to be a third dynamic mode speed, such as a low brake speed 1312 (e.g., one of the plurality of predetermined speed values). For example, the low brake speed 1312 may be approximately 1000 RPMs.

If the freewheeling speed 1310 of the fan assembly 110 is greater than the second dynamic mode speed threshold 1322 (e.g., and/or greater than the first dynamic mode speed threshold 1321, and/or where the freewheeling speed 1310 is greater than the minimum speed threshold 1305), the fan controller 1020 adjusts the speed of the fan assembly 110 to be a fourth dynamic mode speed, such as a high brake speed 1313 (e.g., one of the plurality of predetermined speed values). For example, the high brake speed may be approximately 500 RPMs. In some embodiments, the second dynamic mode speed threshold 1322 may be approximately 2200 RPMs.

Referring to FIG. 19, the process 2000 may include adjusting (e.g., setting) the speed of the fan assembly to be the first dynamic mode speed, at operation 2020. In some embodiments, the process 2000 may include initiating (e.g., activating, powering on, etc.) the fan assembly. For example, adjusting the speed of the fan assembly may include determining if the fan assembly is active, where if the fan assembly is inactive, the fan assembly is activated.

Referring to FIG. 20A, the fan controller 1020 may control operation (e.g., adjust and/or set the speed) of the fan assembly 110 (e.g., the fan motor 112 thereof), based on determining the speed for the fan assembly 110. In some embodiments, the fan assembly 110 (e.g., the fan motor 112 thereof) is powered off (e.g., deactivated, inactive, etc.), the fan controller 1020 powers on (e.g., activates, initiates, etc.) the fan assembly 110.

Referring to FIG. 19, the process 2000 may include determining if the speed of the fan assembly is to be adjusted, based on the first dynamic mode speed and an airflow threshold, at operation 2030. For example, the first dynamic speed may provide a baseline speed of the fan assembly in the dynamic mode (e.g., initial boost speed and/or initial brake speed), where the speed of the fan assembly may be further adjusted based on a determination of the airflow threshold (e.g., a maximum and/or minimum speed and/or a range of desirable speeds determined based on current airflow conditions within the HVAC system). If the first dynamic mode speed provides desirable airflow through an HVAC device (e.g., a humidifier, etc.) positioned in the airstream (e.g., downstream, upstream) of the inline duct fan, the speed of the fan assembly is not adjusted.

In some embodiments, the process 2000 may include determining if a humidification command is active, at operation 2040. For example, based on determining not to adjust the speed of the fan assembly from the first dynamic mode speed, the process 2000 may then include determining whether to transition the inline duct fan from the dynamic mode or continue to determine if the speed of the fan assembly is to be adjusted (e.g., repeating the process 2000). If the humidification command is active, the process 2000 may repeat from operation 2020 and/or operation 2030 (e.g., to continually adjust the speed of the fan assembly while the humidification command is active). If the humidification command is inactive (e.g, ended), the process 2000 may include transitioning the inline duct fan out of the dynamic mode (e.g., to stop dynamically adjusting the speed of the fan assembly). When the inline duct fan leaves the dynamic mode, the process 2000 may end.

In some embodiments, the process 2000 may include determining a second dynamic speed for the fan assembly, based on determining to adjust the speed of the fan assembly from the first dynamic mode speed, at operation 2050. For example, if the first dynamic mode speed does not provide desirable airflow through the HVAC device, the speed of the fan assembly is to be adjusted. In some embodiments, the first dynamic mode speed may be undesirable due to the first dynamic mode speed exceeding the airflow threshold. In some embodiments, while the first dynamic mode speed may not exceed the airflow threshold, the speed of the fan assembly may be adjusted to increase the performance of the HVAC device (e.g., the first dynamic mode speed may not be a desired speed).

Referring to FIG. 20A, the fan controller 1020 may predict a flow rate (e.g., a predicted flow rate), such as a volumetric flow rate, of the air within the HVAC system 1100 (e.g., volumetric flow rate of air within the bypass duct 301 and/or through the inline duct fan 100 and/or HVAC device 120, etc.). For example, the flow rate of the air within the HVAC system 1100 (e.g., the bypass duct 301 and/or through the HVAC device 120, etc.) may be predicted based on one or more of the operational parameters of the fan assembly 110 (e.g., current of the fan motor 112, the speed of the fan assembly 110, etc.). In some embodiments, the fan controller 1020 may predict one or more of an air pressure (e.g., a predicted air pressure), flow rate, and/or air velocity (e.g., air speed) of the air within the HVAC system 1100 (e.g., the bypass duct 301 thereof, etc.). For example, the predicted flow rate of air corresponds to the predicted air pressure. If the predicted flow rate and/or the predicted air pressure does not exceed (e.g., is greater than, is less than, within a range, etc.) the airflow threshold 1302, the fan controller 1020 adjusts (e.g., sets) the speed of the fan assembly 110 to the sound threshold speed 1301. If the predicted flow rate and/or the predicted air pressure exceeds (e.g., is greater than, less than, outside a range, etc.) the airflow threshold 1302, the fan controller 1020 determines and/or adjusts the speed of the fan assembly 110. For example, based on the predicted flow rate and/or the predicted air pressure, the speed of the fan assembly 110 (e.g., the first dynamic mode speed) may exceed and/or be equal to the airflow threshold 1302, where the fan controller 1020 determines and/or adjusts the speed of the fan assembly 110.

The fan controller 1020 may determine a fifth dynamic mode speed, such as an airflow threshold speed 1304. The airflow threshold speed 1304 may be less than or equal to the airflow threshold 1302. For example, in some embodiments, the airflow threshold speed 1304 is a maximum speed for the fan assembly 110, where resulting (e.g., adjusted) airflow caused by the inline duct fan 100 does not exceed the airflow threshold 1302 (e.g., maximum flow rate of air, maximum air pressure, such that the airflow does not cause entrainment within the HVAC system 1100, etc.). The fan controller 1020 may determine the airflow threshold speed 1304 based on one or more of the operational parameters of the inline duct fan 100 (e.g., current, torque, speed of the fan assembly 110, etc.), the predicted flow rate and/or predicted air pressure within the HVAC system 1100, and/or a measured (e.g., detected) airflow conditions (e.g., pressure, temperature, etc.). The fan controller 1020 may determine the sound threshold speed 1301 (e.g., based on one or more of the HVAC command, airflow conditions, etc. of the HVAC system 1100). The fan controller 1020 may determine the speed of the fan assembly 110 based on the airflow threshold speed 1304 and/or the sound threshold speed 1301. For example, the airflow threshold speed 1304 and the sound threshold speed 1301 may be compared, where the speed of the fan assembly 110 is determined to be a lesser (e.g, smaller, lower, etc.) speed of the airflow threshold speed 1304 and the sound threshold speed 1301. The fan controller 1020 may adjust (e.g., set) the speed of the fan assembly 110 to either the airflow threshold speed 1304 and/or the sound threshold speed 1301 (e.g., the lesser speed thereof). Thereby, the speed of the fan assembly 110 is adjusted to a maximum dynamic mode speed to control (e.g., increase, decrease) airflow through the HVAC system 1100, such as through the HVAC device 120 (e.g., the humidifier 320) thereof, which increases the performance of the HVAC device 120 by adjusting the airflow thereto. In some embodiments, the fan controller 1020 may include one or more speed tables including a plurality of speed values for adjusting the speed of the fan assembly 110. For example, the fan controller 1020 may determine and/or adjust the speed of the fan assembly 110 based on the speed values including in the speed table. The fan controller 1020 may select a speed value closest to the lesser of the airflow threshold speed 1304 and/or the sound threshold speed 1301 to determine and/or adjust the speed of the fan controller 1020.

In some embodiments, the first dynamic mode speed may be determined based on one or more of the operational parameters of the inline duct fan 100 (e.g., current, torque, speed of the fan assembly 110, etc.), the predicted flow rate and/or predicted air pressure within the HVAC system 1100, and/or a measured (e.g., detected) airflow conditions (e.g., pressure, temperature, etc.). For example, the fan controller 1020 may determine and/or adjust the speed of the fan assembly 110 to the first dynamic mode speed based on the airflow threshold speed 1304 and/or the sound threshold speed 1301. Thereby, the first dynamic mode speed and/or the second dynamic mode speed may be similarly determined (e.g., the first dynamic mode speed may be determined similarly to the second dynamic mode speed, as described herein, instead of determining the first dynamic mode speed via the one or more dynamic mode speed threshold comparisons, etc.).

In some embodiments, the inline duct fan 100 may be (e.g., remain) in the dynamic mode 1203 after the humidification command ends (e.g., remain for a time period, etc.). For example, the inline duct fan 100 remaining in the dynamic mode 1203 after the humidification command ends provides for the inline duct fan 100 to increase drying of component(s) within the HVAC device 120 (e.g., a water panel of the humidifier 320, etc.), thereby improving the performance of the HVAC device 120.

Referring to FIG. 19, the process 2000 may include adjusting (e.g, setting) the speed of the fan assembly to be the second dynamic mode speed, at operation 2060. Once the speed of the fan assembly is adjusted, the process 2000 may move to operation 2040. In some embodiments, the process 2000 may include determining to stop adjusting the speed of the fan assembly, based on the humidification command is inactive, at operation 2070. In some embodiments, the process 2000 may include determining, based on the humidification command being active, if the speed of the inline duct fan is to be adjusted, based on the second dynamic speed and the airflow threshold, at operation 2080 (e.g, repeating operation 2030 with the second dynamic speed, where in some embodiments, a third dynamic speed is determined and/or set for the inline duct fan). By repeating at least part of (e.g, some operations of) the process 2000, the speed of the fan assembly may be adjusted to various speeds (e.g., a third dynamic mode speed, a fourth dynamic mode speed, etc.) to provide desirable airflow through the HVAC device (e.g., the humidifier) of the HVAC system. Thereby, the process 2000 may be repeated (e.g., continued over time) to dynamically adjust the speed of the inline duct fan, until the humidification command ends (e.g., and/or a fault occurs), and/or the inline duct fan leaves the dynamic mode.

Referring to FIGS. 20A-20B, once the fan controller 1020 determines the speed of the fan assembly 110 (e.g., once the speed of the fan assembly 110 has been adjusted), the fan controller 1020 determines if the HVAC command (e.g., the humidification command) is active (e.g., the fan controller 1020 is receiving the HVAC command). In some embodiments, when the predicted flow rate and/or the predicted air pressure does not exceed (e.g., is greater than, is less than, within a range, etc.) the airflow threshold 1302 (e.g., where the fan controller 1020 does not adjust the speed of the fan assembly 110), the fan controller 1020 determines if the humidification command is active. If the fan controller 1020 is not receiving the humidification command (e.g., the humidification command is inactive, ends, etc.), the inline duct fan 100 is transitioned out of the dynamic mode 1203 (e.g., may enter the idle mode 1202, as described herein). When the humidification command is (e.g., remains) active, the fan controller 1020 may continue to determine and/or adjust the speed of the fan assembly 110, based on the airflow conditions within the HVAC system 1100. Thereby, the speed of the fan assembly 110 may be continuously adjusted (e.g., variable over time) when the inline duct fan 100 is in the dynamic mode 1203.

In some embodiments, if the inline duct fan 100 experiences a fault when the inline duct fan 100 is in the dynamic mode 1203, the inline duct fan 100 may transition to the error mode 1205. For example, the inline duct fan 100 may experience the fault in an event of, but not limited to, the fan assembly 110 not initiating (e.g., failing to power on), and/or the fan controller 1020 failing to determine and/or adjust (e.g., set) the speed of the fan assembly 110 (e.g., communication fault when setting the speed of the fan assembly 110, processing fault of the fan controller 1020 when determining the speed of the fan assembly 110, etc.).

Referring to FIGS. 21 and 22, a process 3000 (e.g., a method) of adjusting airflow within an HVAC system is illustrated. The process 3000 may be completed (e.g., carried out) with an embodiment of the inline duct fan 100, as described herein. In some embodiment, the process 3000 may be used to adjust airflow within an embodiment of the HVAC system 1100, as described herein. In some embodiments, the process 3000 may include additional, fewer, and/or a different order of steps (e.g., operations). For example, as shown in FIG. 22, the speed of the fan assembly 110 of the inline duct fan 100 may be determined and/or adjusted (e.g., set) based on the process 3000 (e.g., determining the second speed for the fan assembly 110 when the inline duct fan 100 is in the block mode 1204 to adjust airflow). For example, the fan controller 1020 may complete (e.g, carry out) the process 3000. When the inline duct fan 100 enters (e.g., changes to, transitions to, etc.) the block mode 1204, the fan controller 1020 may initiate the process 3000.

Referring to FIG. 21, the process 3000 may include determining if a first speed of the inline duct fan is a freewheeling speed, at operation 3010. For example, if the speed of the inline duct fan is a freewheeling speed, a fan assembly of the inline duct fan is not actively operating (e.g., passively blocking airflow by a fan blade freewheeling). If the speed of the inline duct fan is not the freewheeling speed, the fan assembly of the inline duct fan is actively operating (e.g., actively blocking airflow via the fan blade being controlled by a fan motor).

Referring to FIG. 22, when the inline duct fan 100 enters (e.g., changes to) the block mode 1204, the speed of the fan assembly 110 may be a first speed (e.g., an initial speed), where the fan controller 1020 determines and/or adjusts (e.g., sets) the speed of the fan assembly 110 to a second speed, such as a block speed. For example, the speed of the fan assembly 110 may be the block speed to decrease (e.g., block) airflow through the HVAC system 1100 (e.g., the humidifier 320, etc.). In some embodiments, the block speed refers to the speed of the fan assembly 110 in the fan direction (e.g., direction of rotation of the fan assembly 110) causing airflow in substantially the same direction as the airflow within the HVAC system 1100. In some embodiments, the block speed for the fan assembly 110 may refer to the fan direction (e.g., direction of rotation) of the fan assembly 110 causing airflow opposite the airflow direction within the HVAC system 1100, such as through the HVAC device 120 (e.g., the humidifier 320). In some embodiments, for example, when the direction of rotation of the fan assembly 110 is adjusted, the speed of the fan assembly 110 may be increased to block airflow (e.g., operating the fan assembly 110 faster, but in the opposite direction).

In the block mode 1204, the speed of the fan assembly 110 may be determined (e.g., determining the block speed) and/or adjusted (e.g., setting the speed to the block speed) by the fan controller 1020 based on one or more of the environmental conditions (e.g., current airflow conditions) of the HVAC system 1100, HVAC commands, and/or current operating parameters of the inline duct fan 100 (e.g., current supplied to the fan motor 112, torque of the fan motor 112, speed of the fan assembly 110, etc.). Thereby, by adjusting the speed of the inline duct fan 100 to the block speed, airflow conditions within the HVAC system 1100, such as airflow through the HVAC device 120 (e.g., the humidifier 320) thereof, are adjusted to decrease wear and tear and/or damage (e.g., substantially protect) to the HVAC device 120 (e.g., the humidifier 320), and/or decrease undesirable airflow through the bypass duct 301 of the HVAC system 1100 (e.g., since airflow is unnecessary through the bypass duct 301 when the HVAC device 120 is inactive, etc.).

When in the block mode 1204, the speed of the fan assembly 110 may vary between a plurality of speed values, as determined and/or set by the fan controller 1020, based on the airflow (e.g, environmental conditions and/or HVAC commands within the HVAC system 1100. In some embodiments, the speed of the fan assembly 110 may be adjusted (e.g., set) by the fan controller 1020 to one of a plurality of predetermined speed values and/or ranges.

In some embodiments, the fan controller 1020 is communicably coupled to one or more sensors configured to detect the airflow conditions (e.g., pressure, temperature, etc.) within the HVAC system 1100 (e.g., disposed at least partially within the ducts thereof), where the fan controller 1020 receives sensor data from one or more sensors indicative of the airflow conditions within the HVAC system 1100. Based on the sensor data, the fan controller 1020 may determine and/or set the speed of the fan assembly 110 of the inline duct fan 100 to adjust airflow within the HVAC system 1100. In some embodiments, the fan controller 1020 may receive data indicative of the airflow conditions (e.g., pressure, temperature, etc.) within the HVAC system 1100 from the HVAC controller 1120.

In some embodiments, the fan controller 1020 determines airflow conditions (e.g., and/or changes thereof, such as over a time period), such as air pressure, within the HVAC system 1100 based on operational parameters of the inline duct fan 100, such as the fan assembly 110 thereof (e.g., thereby the fan controller 1020 may determine air pressure without direct pressure sensing via one or more sensors disposed throughout the HVAC system 1100). For example, the operational parameters of the inline duct fan 100 may include, but are not limited to, a current of the fan motor 112, a voltage supplied to and/or a back electromotive force (BEMF) applied on the fan motor 112, a torque of the fan assembly 110 (e.g., the fan blade 111 and/or the fan motor 112 thereof, etc.), and/or the speed of the fan assembly 110 (e.g., the fan blade 111 and/or the fan motor 112 thereof, etc.).

Referring to FIG. 22, in the block mode 1204, the fan assembly 110 may be configured to passively block airflow (e.g., where the fan blade 111 freewheels based on the airflow through the inline duct fan 100 within the HVAC system 1100), and/or actively block airflow (e.g., where the fan assembly 110 is controlled to operate at a determined speed and/or a set speed). When the inline duct fan 100 enters the block mode 1204, the first speed of the fan assembly 110 may be a freewheeling speed 1401 (e.g., speed due to passive rotation of the fan blade 111 due to airflow through the inline duct fan 100, such that the fan blade 111 is not powered by the fan motor 112). For example, the speed of the fan assembly 110 may be the freewheeling speed 1401 until the fan controller 1020 determines the speed of the fan assembly 110 to be the block speed (e.g., actively operating the fan assembly 110 to block airflow). In some embodiments, when the inline duct fan 100 enters the block mode 1204, if the speed of the fan assembly 110 is not the freewheeling speed 1401, the fan controller 1020 may deactivate the fan assembly 110, such that the speed of the fan assembly 110 adjusts to the freewheeling speed 1401.

Referring to FIG. 21, the process 3000 may include determining, based on the first speed of the fan assembly being the freewheeling speed, if the freewheeling speed of the inline duct fan exceeds a speed threshold, at operation 3020. For example, the freewheeling speed may be compared to one or more speed thresholds. In some embodiments, a second speed of the inline duct fan (e.g., a block speed), may be variable, based on the one or more speed thresholds. The block speed may be one of one or more predetermined blocks speeds. For example, determining if the freewheeling speed of the inline duct fan exceeds a speed threshold may include sequentially comparing the freewheeling speed to the one or more speed thresholds until the block speed for the inline duct fan is determined (e.g., where the freewheeling speed exceeds and/or does not exceed one of the speed thresholds.

The process 3000 may include determining and/or adjusting (e.g., setting) a speed of the inline duct fan to be a second speed (e.g., a block speed), at operation 3030. For example, adjusting the speed of the inline duct fan may include initiating (e.g., starting, powering on, etc.) the fan assembly (e.g., the fan motor thereof) of the inline duct fan.

Referring to FIG. 22, in the block mode 1204, if the freewheeling speed 1401 of the fan assembly 110 is greater than a first block mode speed threshold 1402 (e.g., a first block speed threshold, a high block mode speed threshold, etc.), the fan controller 1020 adjusts the speed of the fan assembly 110 to be a first block mode speed 1411 (e.g., a high block speed, such as one of the plurality of predetermined speed values). In some embodiments, the first block mode speed threshold 1402 may be approximately 2200 RPMS. In some embodiments, the first block mode speed 1411 may be approximately 500 RPMs.

If the freewheeling speed 1401 of the fan assembly 110 is less than or equal to the first block mode speed threshold 1402 and/or the freewheeling speed 1401 of the fan assembly 110 is greater than a second block mode speed threshold 1403 (e.g., a second block speed threshold, a low block mode speed threshold, etc.), the fan controller 1020 adjusts the speed of the fan assembly 110 to be a second block mode speed 1412 (e.g., a low block speed, such as one of the plurality of predetermined speed values). In some embodiments, the second block mode speed threshold 1403 may be approximately 1700 RPMS. In some embodiments, the second block mode speed 1412 may be approximately 1000 RPMs.

Referring to FIG. 21, the process 3000 may include determining if one or more HVAC commands are active, at operation 3040. For example, based on adjusting the speed of the inline duct fan, the process 3000 may then include determining whether to transition the inline duct fan from the block mode or continue to determine if the speed of the fan assembly is to be adjusted (e.g., repeating at least part of the process 3000). In some embodiments, the one or more HVAC commands may include a temperature command (e.g., to heat and/or cool the air), an air circulation command (e.g., to operate a central fan of the HVAC system), and/or a humidification command. If the humidification command is inactive, and/or the temperature command or the air circulation command is active, the process 3000 may repeat, such as from operation 3010 (e.g., to continually adjust the speed of the fan assembly, such as for the duration of the temperature command or air circulation command, where the humidification command is inactive).

In some embodiments, the process 3000 may include determining to stop adjusting the speed of the inline duct fan, based on a humidification command being active, and/or a temperature command or an air circulation command being inactive, at operation 3070. For example, stopping determination and/or adjustment of the speed of the inline duct fan may include transitioning the inline duct fan from the block mode. When the inline duct fan leaves the block mode, the process 3000 may end.

Referring to FIG. 22, in some embodiments, if the freewheeling speed 1401 of the fan assembly 110 is less than or equal to the second block mode speed threshold 1403, the fan controller 1020 may determine if one or more HVAC commands are active and/or inactive (e.g., if the fan controller 1020 is receiving one or more HVAC commands). In some embodiments, once the fan controller 1020 determines and/or adjusts the speed of the fan assembly 110, the fan controller 1020 may determine if one or more HVAC commands are active and/or inactive. For example, if the fan controller 1020 is receiving the temperature command and/or the air circulation command (e.g., said commands are active), and not receiving the humidification command (e.g., said command is inactive), the fan controller 1020 may determine and/or adjust the speed (e.g., the block speed) of the fan assembly 110. In some embodiments, the fan controller 1020 continues to determine and/or adjust the speed of the fan assembly 110, such that the fan assembly 110 continues passively blocking airflow until the fan controller 1020 determines to actively block airflow (e.g., determine and/or adjust the speed of the fan assembly 110) and/or transition the inline duct fan 100 out of the block mode 1204. In some embodiments, if the fan controller 1020 receives the humidification command, the inline duct fan 100 is transitioned out of the block mode 1204 (e.g., and into the idle mode 1202, into the dynamic mode 1203). In some embodiments, if the fan controller 1020 does not receive the temperature command and/or the air circulation command, the inline duct fan 100 is transitioned out of the block mode 1204 (e.g., and into the idle mode 1202).

Referring to FIG. 21, the process 3000 may include determining, based on the speed of the inline duct fan not being the freewheeling speed, if an operational parameter of the inline duct fan exceeds an operational parameter threshold, at operation 3050. For example, if the fan assembly of the inline duct fan is actively operating, operation 3050 may be used to determine if the inline duct fan is blocking a desirable amount of airflow (e.g., not over-blocking airflow). In some embodiments, if the operational parameter (e.g., current, torque, etc.) of the inline duct fan does not exceed the operational parameter threshold, the process 3000 may move to operation 3040 (e.g., to determine if the HVAC commands are active and/or inactive). The process 3000 may include determining and/or adjusting (e.g., setting) the speed of the inline duct fan, based on the operational parameter of the inline duct fan exceeding the operational parameter threshold, at operation 3060. In some embodiments, the speed of the inline duct fan may be the second speed. In some embodiments, the speed of the inline duct fan may be a third speed. In some embodiments, adjusting the speed of the inline duct fan may include deactivating (e.g., powering off, etc.) the fan assembly (e.g., the fan motor thereof) of the inline duct fan, such that the speed of the inline duct fan adjusts to the freewheeling speed.

Referring to FIG. 22, if the fan assembly 110 is actively blocking airflow (e.g., the speed of the fan assembly 110 is the block speed, such as the first block mode speed 1411 and/or the second block mode speed 1412, etc.), the fan controller 1020 may determine and/or adjust the speed of the fan assembly 110 (e.g., adjust the block speed, switch to passive blocking via the freewheeling speed 1401, etc.). In some embodiments, the fan controller 1020 may determine if one or more operational parameters of the inline duct fan 100 exceeds an operational parameter threshold. For example, the fan controller 1020 may determine if a torque of the fan assembly 110 (e.g., the fan motor 112 thereof) is greater than a torque threshold (e.g., determine if torque is positive, such that a positive torque is indicative of the fan assembly 110 boosting airflow, and/or determine if torque is negative, such that a negative torque is indicative of the fan assembly 110 block airflow, etc., where the direction of rotation of the fan assembly 110 is aligned with the airflow direction, etc.). For another example, the fan controller 1020 may determine if a current of the fan assembly 110 (e.g., the fan motor 112 thereof) is greater than a current threshold (e.g., determine if current is positive, such that a positive current is indicative of the fan assembly 110 boosting airflow, and/or determine if current is negative, such that a negative current is indicative of the fan assembly 110 block airflow, etc., where the direction of rotation of the fan assembly 110 is aligned with the airflow direction, etc.). Based on the operational parameter (e.g., torque) exceeding (e.g., being greater than, less than, outside a threshold range) the operational parameter threshold (e.g., torque threshold), if the speed of the fan assembly 110 is the first block mode speed 1411, the fan controller 1020 determines and/or adjusts the speed of the fan assembly 110 to the second block mode speed 1412. In some embodiments, based on the operational parameter exceeding the operational parameter threshold, if the speed of the fan assembly 110 is not the first block mode speed 1411 (e.g., the speed is the second block mode speed 1412), the fan controller 1020 determines that the inline duct fan 100 is to passively block airflow. The fan controller 1020 may deactivate the fan assembly 110, such that the speed of the fan assembly 110 becomes the freewheeling speed 1401. In some embodiments, once the fan controller 1020 determines and/or adjusts the speed of the fan assembly 110 based on the operational parameter of the fan assembly 110, the fan controller 1020 may determine if one or more HVAC commands are active and/or inactive (e.g., if the fan controller 1020 is receiving one or more HVAC commands), as described herein.

Referring to FIG. 22, the fan controller 1020 may control operation (e.g., adjust and/or set the speed) of the fan assembly 110 (e.g., the fan motor 112 thereof), based on determining the speed for the fan assembly 110. In some embodiments, the fan assembly 110 (e.g., the fan motor 112 thereof) is powered off (e.g., deactivated, inactive, etc.), the fan controller 1020 powers on (e.g., activates, initiates, etc.) the fan assembly 110. For example, the fan controller 1020 may activate the fan assembly 110 and adjust the speed thereof to the block speed (e.g., the first block mode speed 1411, the second block mode speed 1412, etc.). In some embodiments, if the fan assembly 110 is activated, and the fan controller 1020 determines the fan assembly 110 is to passively block airflow, the fan controller 1020 may deactivate the fan assembly 110 (e.g., so the fan assembly 110 may operate at the freewheeling speed 1401, etc.).

In some embodiments, if the inline duct fan 100 experiences a fault when the inline duct fan 100 is in the block mode 1204, the inline duct fan 100 may transition to the error mode 1205. For example, the inline duct fan 100 may experience the fault in an event of, but not limited to, the fan assembly 110 not initiating (e.g., failing to power on), the fan controller 1020 failing to determine and/or adjust (e.g., set) the speed of the fan assembly 110 (e.g., communication fault when setting the speed of the fan assembly 110, processing fault of the fan controller 1020 when determining the speed of the fan assembly 110, etc.), airflow conditions failing to meet expected airflow conditions, such as exceeding threshold values (e.g., air temperature over, under, and/or outside of an air temperature threshold or threshold range, air pressure in the bypass duct 301 greater than a safe air pressure threshold, etc.), operational parameters failing to meet expected operational parameter values, such as exceeding threshold values, and/or stalling of the fan assembly 110.

In some embodiments, when the inline duct fan 100 is in the block mode 1204 and/or the dynamic mode 1203, such as where the speed of the fan assembly 110 is adjusted to decrease (e.g., brake, block, etc.) airflow within the HVAC system 1100, the inline duct fan 100 may notify (e.g., transmit a notification to, etc.) a user that the speed of the inline duct fan 100 is adjusted to decrease airflow. For example, the inline duct fan 100 decreasing airflow within the HVAC system 1100 may be indicative of undesirable airflow conditions within the HVAC system 1100, such that maintenance on the HVAC system 1100 may be performed to correct the airflow conditions (e.g., undesirable airflow conditions may include a high static pressure, etc.).

Referring to FIG. 23, a process 4000 (e.g., a method) to control operation of the inline duct fan via a plurality of operating modes is illustrated. For example, the process 4000 may be completed (e.g, carried out) to switch (e.g., change, transition, move, etc.) the inline duct fan between the plurality of operating modes for adjusting airflow within an HVAC system (e.g., through an HVAC device, such as a humidifier, thereof). In some embodiments, the process 4000 may be completed (e.g., carried out) with an embodiment of the inline duct fan 100, as described herein. In some embodiment, the process 4000 may be used to adjust airflow within an embodiment of the HVAC system 1100, as described herein. In some embodiments, the process 4000 may include additional, fewer, and/or a different order of steps (e.g., operations).

For example, the process 4000 may include configuring a fan controller of an inline duct fan to operate the inline duct fan in one or a plurality of operating modes, at operation 4010. For example, the plurality of operating modes may include one or more of the plurality of operating modes 1200, such as the initial mode 1201, the idle mode 1202, the dynamic mode 1203, the block mode 1204, and/or the error mode 1205. The process 4000 may include detecting (e.g., receiving) one or more HVAC commands, at operation 4020. For example, the inline duct fan (e.g., the fan controller thereof) may detect the HVAC command from an HVAC controller within an HVAC system (e.g., that the inline duct fan is installed in). The HVAC command may include, but is not limited to, a humidification command (e.g., to increase moisture in the air), a temperature command (e.g., to increase, decrease air temperature), and/or an air circulation command (e.g., to operate a central fan of the HVAC system). The process 4000 may include transitioning the inline duct between the plurality of operating modes, based on the HVAC command, at operation 4030. The process 4000 may include operating the inline duct fan, based on the inline duct fan being in one of the plurality of operating modes, at operation 4040. For example, operation of the inline duct fan may vary based on the inline duct fan being in various operating modes of the plurality of operating modes. Operating the inline duct fan may include determining and/or adjusting a fan speed of the inline duct fan. The fan speed of the inline duct fan may be adjusted differently based on being in various operating modes of the plurality of operating modes. For example, plurality of operating modes may be used to control operation of the inline duct fan to increase (e.g., boost) and/or decrease (e.g., brake, block) airflow within the HVAC system (e.g., through an HVAC device thereof, such as a humidifier). In some embodiments, the fan speed of the inline duct fan may be determined and/or adjusted based on the process 2000, as described herein, for example, where the inline duct fan is in the dynamic mode 1203. In some embodiments, the fan speed of the inline duct fan may be determined and/or adjusted based on the process 3000, as described herein, for example, where the inline duct fan is in the block mode 1204.

Referring to FIGS. 24A-24B, in some embodiments, the inline duct fan 100 includes one or more switches 1500 (e.g., configuration switches to adjust a configuration of the inline duct fan, such as fan direction, maximum speed for the fan assembly 110, and/or provide feedback to a user to improve maintenance and/or installation, etc.). A user may provide user input to the fan controller 1020 (e.g., the first controller 151 thereof), via the one or more switches 1500 (e.g., and/or other buttons, switches, etc.) of the inline duct fan 100). For example, the one or more switches 1500 may be positioned on and/or extend through the housing 102. The one or more switches 1500 may be configured to receive user input (e.g., to change a position thereof). The one or more switches 1500 are communicably coupled to the fan controller 1020 (e.g., the first controller 151). For example, a position (e.g., setting) of a switch of the one or more switches 1500 may be an input used by the fan controller 1020 to make various determinations, as described herein. In some embodiments, the one or more switches 1500 may be configured as inputs to the fan controller 1020, where the input is provided as a digital input via a wireless connection (e.g., Wi-Fi, Bluetooth, etc.) from an external device (e.g., user device, etc.).

The one or more switches 1500 may include a first switch 1501 (e.g., configuration switch, performance switch, etc.) configured to provide (e.g., set) a speed of the fan assembly 110 (e.g., a predetermined speed). For example, the first switch 1501 may provide the sound threshold speed 1301. In some embodiments, the first switch 1501 may be configured to adjust the sound threshold speed 1301, based on a position of the first switch 1501 (e.g., the sound threshold speed 1301 is configurable by adjusting the position of the first switch 1501). For example, in a first position of the first switch 1501, the sound threshold speed 1301 may be a first sound threshold speed (e.g., a low speed). In a second position of the first switch 1501, the sound threshold speed 1301 may be a second sound threshold speed (e.g., a medium speed). In a third position of the first switch 1501, the sound threshold speed 1301 may be a third sound threshold speed (e.g., a high speed). For example, when the fan controller 1020 determines the sound threshold speed 1301, the fan controller 1020 may determine the position of the first switch 1501, which is indicative of the sound threshold speed 1301 (e.g., predetermined sound threshold speed as configured by the position of the first switch 1501).

In some embodiments, when the inline duct fan 100 is in the dynamic mode 1203, the fan controller 1020 determines the speed of the fan assembly 110 at least partially based on the temperature command and/or the air circulation command (e.g., the air temperature of the air being circulated). For example, the sound threshold speed 1301 may vary based on the temperature command and/or the air circulation command being active. When the temperature command is active, the sound threshold speed 1301 (e.g., as configured by the first switch 1501) may be greater than the sound threshold speed 1301 when the air circulation command is active (e.g., when the air temperature increases, the speed of the inline duct fan 100 increases to increase the performance of the humidifier 320 by increasing airflow therethrough, etc.). In some embodiments, when the air circulation command is active, the first sound threshold speed may be approximately 1700 RPMs. When the temperature command is active, the first sound threshold speed may be approximately 2550 RPMs. In some embodiments, when the air circulation command is active, the second sound threshold speed may be approximately 2100 RPMs. When the temperature command is active, the second sound threshold speed may be approximately 2700 RPMs. In some embodiments, when the air circulation command is active, the third sound threshold speed may be approximately 2300 RPMs. When the temperature command is active, the first sound threshold speed may be approximately 2900 RPMs. Thereby, the first switch 1501 provides a user-selectable performance mode so the sound threshold speed 1301 may be adjustment between high, medium, and/or low levels depending on the environment conditions within the HVAC system 1100 and/or sound sensitivity within the building (e.g., user preferences, etc.). In some embodiments, the inline duct fan 100 may be configured to operate at a constant speed, based on the inline duct fan 100 being in one of the plurality of operating modes 1200 (e.g., the dynamic mode 1203, the block mode 1204, etc.). For example, when in the dynamic mode 1203, the speed of the inline duct fan 100 (e.g., the fan assembly 110 thereof) may be determined based on the position of the first switch 1501, where the inline duct fan 100 operates at said speed until exiting the dynamic mode 1203. In some embodiments, the speed of the inline duct fan 100 (e.g., the fan assembly 110 thereof) may be determined based on a predetermined speed, as described herein, where the inline duct fan 100 operates at said speed until transitioning between an operating mode of the plurality of operating modes 1200 (e.g., operating at a constant speed while within an operating mode, etc.).

The one or more switches 1500 may include a second switch 1502 (e.g., first mounting switch, first installation switch, etc.). For example, the second switch 1502 is configured to provide feedback (e.g., visual indication) to a user (e.g., installer, contractor, tenant, occupant, etc.) as to a mounting (e.g., installation) location of the inline duct fan 100 within the HVAC system 1100. A first position of the second switch 1502 may indicate that the inline duct fan 100 is mounted on (e.g., coupled to) the HVAC device 120 (e.g., the humidifier 320). A second position of the second switch 1502 may indicate that the inline duct fan 100 is mounted on ductwork within the HVAC system 1100 (e.g., the supply air duct 302, the return air duct 303, etc.).

The one or more switches 1500 may include a third switch 1503 (e.g., second mounting switch, second installation switch, etc.). For example, the third switch 1503 is configured to provide feedback to the user as to a mounting location of the inline duct fan 100 and/or the HVAC device 120 (e.g., the humidifier 320, etc.) within the HVAC system 1100 (e.g., ductwork and/or plenum(s), etc.). A first position of the third switch 1503 may indicate that the inline duct fan 100 is mounted on the supply air duct 302. A second position of the third switch 1503 may indicate that the inline duct fan 100 is mounted on the return air duct 303.

In some embodiments, a fan direction (e.g., clockwise or counterclockwise, push or pull of air, upstream or downstream from HVAC device 120, etc.) of the fan assembly 110 may be adjusted by adjusting the position of the second switch 1502 and/or the third switch 1503. In some embodiments, one or more operational parameters of the inline duct fan 100 may be adjusted by adjusting the position of the second switch 1502 and/or the third switch 1503. In some embodiments, based on positions of the second switch 1502 and/or the third switch 1503, the user may configure and/or troubleshoot the inline duct fan 100. For example, the second switch 1502 and/or the third switch 1503 provide for the user to determine the fan direction of the inline duct fan 100 (e.g., where the fan direction may differ if the inline duct fan 100 is mounted on the supply air duct 302 and/or the return air duct 303, etc.). For another example, the second switch 1502 and/or the third switch 1503 provide for the user to configure the one or more operational parameters based on the mounting location of the inline duct fan 100 (e.g., adjust the operational parameters based on performance differences when the inline duct fan 100 is pushing air through the humidifier 320 compared to pulling air through the humidifier 320, and/or to adjust for variable pressure differentials within the HVAC system 1100, etc.). In some embodiments, the one or more switches 1500 may include a switch (e.g., a fourth switch, etc.) configured to adjust a power level for the inline duct fan 100 (e.g., power saving mode, etc.). In some embodiments, the one or more switches 1500 may include a switch (e.g., a fourth switch, a fifth switch, etc.) to configure the inline duct fan 100 for operation with a specific model of HVAC device 120 (e.g., where various determinations, thresholds, and/or predetermined speeds are adjusted based on the model of HVAC device 120, etc.). Thereby, the one or more switches 1500 decrease installation, testing, and/or troubleshooting time spent by the user, and/or provide for the inline duct fan 100 to be installed in various HVAC systems (e.g., providing configuration flexibility for operation of the inline duct fan 100 based on various models of humidifiers, such as different water panel pressure drops, various types of ductwork within the system, mounting configuration of the humidifier, etc.).

In some embodiments, the inline duct fan 100 may be configured to operate in one or more performance configurations (e.g., where the predetermined speed values and/or the threshold values, as described herein, may differ based on a performance configuration of the inline duct fan 100, etc.). For example, the inline duct fan 100 may be operated in a first performance configuration, such as a default configuration. The inline duct fan 100 may be operated in a second performance configuration, where the predetermined speed values and/or the threshold values are adjusted (e.g., differ, such as lower and/or greater than in the first performance configuration) based on a type of the HVAC device 120 (e.g., specifications of the humidifier 320 etc.). For example, when the HVAC system 1100 includes the humidifier 320, if the humidifier 320 is a smaller humidifier (e.g., outputting a lower amount of humidified air, as compared to other available humidifiers, etc.), the predetermined speed values and/or the threshold values may be lower compared to larger humidifiers. Thereby, the inline duct fan 100 may be operated in the second performance configuration to adjust the predetermined speed values and/or the threshold values to provide lower airflow through the HVAC system 1100 (e.g., the bypass duct 301 and/or the humidifier 320 thereof) compared to when the HVAC system 1100 includes larger humidifiers. In some embodiments, the one or more performance configurations may be switched between (e.g., adjusted, changed, etc.) based on adjusting a position of a switch (e.g., one of the one or more switches 1500) and/or pressing a button (e.g., one of the one or more buttons 142) of the inline duct fan 100 (e.g., holding a button for a number of seconds to change the performance configuration of the inline duct fan 100). The fan controller 1020 may be configured to control the inline duct fan 100 based on the performance configuration thereof.

In some embodiments, the inline duct fan 100 (e.g., the fan controller 1020 thereof, etc.) may be configured to mitigate (e.g., prevent, limit, etc.) a temperature fault within the HVAC system 1100. For example, the fan controller 1020 may determine an air temperature with the HVAC system 1100 (e.g., the bypass duct 301 thereof, such as via a temperature sensor at least partially positioned within said duct, etc.). The air temperature is compared to an air temperature threshold (e.g., a temperature value that triggers a temperature fault within the HVAC system 1100 and/or equipment thereof, such as a high temperature fault or a low temperature fault, etc.). If the air temperature exceeds (e.g., is greater than, is less than, outside of a range for, etc.) the air temperature threshold, the speed of the fan assembly 110 is adjusted (e.g., to mitigate an occurrence of the high temperature fault, etc.). For example, if the air temperature is greater than a first air temperature threshold (e.g., a high air temperature threshold, for example, 160 degrees Fahrenheit, etc.), the speed of the fan assembly 110 may be adjusted to a brake speed or a block speed (e.g., the first block mode speed 1411, the second block mode speed 1412, the low brake speed 1312, the high brake speed 1313, etc.). For another example, if the air temperature is less than a second air temperature threshold (e.g., a low air temperature threshold, etc.), the speed of the fan assembly 110 may be adjusted to the brake speed or the block speed (e.g., the first block mode speed 1411, the second block mode speed 1412, the low brake speed 1312, the high brake speed 1313, etc.). Thereby, the inline duct fan 100 may be used to mitigate (e.g., prevent) temperature faults within the HVAC system 1100 (e.g., excess recirculation of air, frozen HVAC coils, etc.), which may maintain operation of equipment within the HVAC system 1100 (e.g., a furnace, the HVAC fan 1105, the humidifier 320, etc.) by adjusting airflow to substantially prevent the temperature fault from occurring (e.g., and causing the equipment to shut down until the air temperature stops exceeding the air temperature threshold, etc.), and/or mitigates damage to the equipment within the HVAC system 1100 caused by temperature faults therein.

In some embodiments, the inline duct fan 100 may include one or more status indicators configured to provide feedback on (e.g, indication of) a performance (e.g., an operation and/or an event) of the inline duct fan 100. For example, the inline duct fan 100 may include one or more light emitting diodes (LEDs). The LEDs may be coupled (e.g., electrically, communicably) to the fan controller 1020. The LEDs are configured to provide visual feedback to a user (e.g., resident, tenant, occupant, installer or contractor, technician, etc.) indicative of the performance of the inline duct fan 100. For example, the LEDs may provide feedback indicative of a status of the inline duct fan 100. In some embodiments, the LEDs may transition (e.g., change color, operate in a sequence, power on/off, etc.) between a plurality of states, for example, a plurality of colors and/or sequential patterns, based on the status of the inline duct fan 100. For example, the LEDs may be in and/or transition to a first state (e.g., green light) during normal operation of the inline duct fan 100 (e.g., in the idle mode 1202, no faults, etc.). In some embodiments, the fan controller 1020 may be configured to transmit one or more notifications to the external device (e.g., user device), where the notifications are indicative of the performance of the inline duct fan 100 (e.g., providing feedback in conjunction with and/or instead of the LEDs, etc.). For example, the inline duct fan 100 may be communicably coupled with the user device via a wireless connection (e.g., Wi-Fi, Bluetooth, etc.).

When the inline duct fan 100 is in the dynamic mode 1203 and/or the block mode 1204 the LEDs may activate to indicate an operation being performed by the inline duct fan 100. For example, the LEDs may change state based on the fan controller 1020 adjusting the speed of the fan assembly 110, such as to boost, brake, and/or block airflow within the HVAC system 1100 (e.g., through the HVAC device 120 thereof). In some embodiments, the LEDs may be in and/or transition to the first state (e.g., green light) when the inline duct fan 100 is increasing airflow (e.g., in the dynamic mode 1203, boosting airflow, etc.). In some embodiments, the LEDs may be in and/or transition to a second state (e.g., yellow light) when the inline duct fan 100 is decreasing airflow (e.g., in the dynamic mode 1203 and/or braking airflow, in the block mode 1204, etc.). For example, the LEDs being the second state may provide feedback indicative of high static pressure within the HVAC system 1100 (e.g., such that the inline duct fan 100 is decreasing airflow therein). Prolonged high static pressure within the HVAC system 1100 may be indicative of issues within the HVAC system 1100, even with the inline duct fan 100 increasing performance and/or limiting damage to the one or more HVAC devices 1110 and/or the HVAC system 1100 by decreasing airflow therethrough.

In some embodiments, the LEDs may be in and/or transition to a third state (e.g., blinking yellow light) to indicate a fault. The fault may be temporary (e.g., recoverable, such that the fault will clear once conditions causing the fault are resolved, such as via user troubleshooting, etc.). In some embodiments, the LEDs may be in and/or transition to a fourth state (e.g., red light) to indicate a fault. The fault may be permanent (e.g., requiring maintenance on components of the inline duct fan 100). When the LEDs indicate a fault, the inline duct fan 100 may be in and/or transition into the error mode 1205.

In some embodiments, the LEDs may be in and/or transition to a fifth state (e.g., white light, blinking white light) to indicate a test operation and/or the inline duct fan 100 being in a test mode (e.g., where the test mode may be one of the plurality of operating modes 1200). For example, the test mode may be entered via user input (e.g., pressing one or more buttons and/or a sequence thereof, moving a switch, etc.). For example, the user may provide the user input to the fan controller 1020 (e.g., the first controller 151 thereof), such as where the user engages a button, switch, etc. on and/or extending through the housing 102 of the inline duct fan 100.

In some embodiments, the inline duct fan 100 (e.g., the fan controller 1020 thereof) may be communicably coupled to an external device, such as a user interface (e.g., the HVAC controller 1120, a personal device such as a smartphone or a computer, etc.). In some embodiments, the inline duct fan 100 may provide data indicative of the performance of the inline duct fan 100 to the external device, for example, so the user may receive feedback on the performance of the inline duct fan 100 (e.g., monitor performance of the inline duct fan 100 and/or the HVAC system 1100, alerted when a fault occurs such that the user may contact a technician to repair said fault, etc.). In some embodiments, the inline duct fan 100 may be controlled via the user interface (e.g., via the one or more switches 1500, etc.).

In some embodiments, the inline duct fan 100 may determine a position of a damper within the HVAC system 1100 (e.g., the damper blade 124 of the HVAC device 120, etc.). For example, based on the position of the damper, the inline duct fan 100 may transmit a signal (e.g., notification) to an external device (e.g., a user device), where the signal indicates to adjust (e.g., open, partially open or close, close, etc.) the position of the damper. The inline duct fan 100 (e.g., the fan controller 1020 thereof) may determine the position of the damper based on the operational parameters of the inline duct fan 100. For example, the fan controller 1020 may compare the operational parameters to operational parameter thresholds (e.g., desired operational parameter values, etc.) to determine if the operational parameters exceed the operational parameter thresholds (e.g., if the damper is closed when it should be open, etc.). Based on the operational parameters exceeding the operational parameter thresholds, the fan controller 1020 may notify the user to adjust the position of the damper (e.g., open the damper, etc.). In some embodiments, the inline duct fan 100 may determine the air temperature within HVAC system 1100 (e.g., within the bypass duct 301 and/or through the HVAC device 120, such as the humidifier 320), where based on the air temperature, the inline duct fan 100 may notify the may notify the user to adjust the position of the damper (e.g., where the damper is open when it should be closed, etc.). For example, if the air temperature is less than an air temperature threshold (e.g., cold temperature threshold), the fan controller 1020 may notify the user to adjust the position of the damper (e.g., close the damper, etc.).

Notwithstanding the embodiments described above in FIGS. 1 – 24B, various modifications and inclusions to those embodiments are contemplated and considered within the scope of the present disclosure.

As utilized herein with respect to numerical ranges, the terms “approximately,” “about,” “substantially,” and similar terms generally mean +/- 10% of the disclosed values, unless specified otherwise. As utilized herein with respect to structural features (e.g., to describe shape, size, orientation, direction, relative position, etc.), the terms “approximately,” “about,” “substantially,” and similar terms are meant to cover minor variations in structure that may result from, for example, the manufacturing or assembly process and are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims.

It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with one another, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.

References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below”) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.

Although the figures and description may illustrate a specific order of method steps, the order of such steps may differ from what is depicted and described, unless specified differently above. Also, two or more steps may be performed concurrently or with partial concurrence, unless specified differently above.

It is important to note that any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein. Although only one example of an element from one embodiment that can be incorporated or utilized in another embodiment has been described above, it should be appreciated that other elements of the various embodiments may be incorporated or utilized with any of the other embodiments disclosed herein.

Other embodiments are set forth in the following claims.

Claims

1. An inline duct fan for moving air through an HVAC system, the inline duct fan comprising:

a housing comprising: a body portion comprising: a surface; a first flange extending from the surface adjacent to a first side portion; and a second flange extending from the surface adjacent to a second side portion; the first side portion extending outward from the body portion, wherein the first flange of the body portion extends around the first side portion, and the first side portion comprising a mounting tab, wherein the mounting tab defines one or more first mounting holes therethrough; and the second side portion positioned opposite the first side portion and extending outward from the body portion, wherein the second flange extends around the second side portion, and the second side portion defining one or more second mounting holes therethrough; wherein the second side portion is configured to be mounted to either (i) ductwork, wherein the second side portion extends at least partially within the ductwork, or (ii) an HVAC device via the one or more second mounting holes; and a fan assembly including a fan blade and a fan motor, wherein the fan assembly is positioned at least partially within the first side portion of the housing.

2. The inline duct fan of claim 1, wherein the first side portion of the inline duct fan is configured to be positioned at least partially within a first duct of the HVAC system such that the first duct extends to the mounting tab of the first side portion, and wherein the first side portion is mounted to the duct via the one or more first mounting holes of the mounting tab.

3. The inline duct fan of claim 1, further comprising:

a shroud positioned over the body portion of the housing, the shroud extending between the first flange and the second flange; and

processing circuitry positioned on a surface of the body portion underneath the shroud.

4. The inline duct fan of claim 1, further comprising a shroud positioned over the body portion of the housing, wherein the shroud defines one or more third mounting holes therethrough, and wherein when the second side portion is mounted to the ductwork, the shroud is mounted onto the ductwork via the one or more third mounting holes.

5. The inline duct fan of claim 1, further comprising processing circuitry configured to control operation of the inline duct fan, the processing circuitry comprising:

a first controller positioned along a circumference of the surface of the body portion of the inline duct fan, the first controller configured to operate the fan assembly; and

a second controller communicably coupled to the first controller and positioned opposite the first controller along the circumference of the surface of the body portion of the inline duct fan, wherein the second controller is communicably coupled to the HVAC system for controlling the inline duct fan.

6. A system comprising:

a humidifier coupled to ductwork to humidify air;

a bypass duct coupled to the humidifier and the ductwork;

an inline duct fan positioned between the ductwork and the humidifier, the inline duct fan comprising: a first side portion connected to the bypass duct; a second side portion connected to either (i) ductwork, where the second side portion extends at least partially within the ductwork, or (ii) the humidifier via one or more mounting holes; and processing circuitry communicably coupled to the humidifier, the processing circuitry configured to control operation of the inline duct fan.

7. The system of claim 6, wherein the ductwork comprises a return air duct and a supply air duct, and wherein the bypass duct connects the return air duct to the supply air duct for airflow with the ductwork.

8. The system of claim 7, wherein the humidifier is coupled to the return air duct and the inline duct fan is connected to the humidifier and the bypass duct, the bypass duct further connected to the supply air duct, and wherein the inline duct fan is configured to move air from the supply air duct through the bypass duct and into the humidifier for humidification and circulation of humidified air through the return air duct.

9. The system of claim 7, wherein the humidifier is coupled to the supply air duct and the inline duct fan is connected to the return air duct and the humidifier, and wherein the inline duct fan is configured to move humidified air from the humidifier through the bypass duct and into the return air duct.

10. The system of claim 7, wherein the humidifier is coupled to the return air duct and the inline duct fan is connected to the supply air duct and the bypass duct, the bypass duct further connected to the humidifier, and wherein the inline duct fan is configured to move air from the supply air duct through the bypass duct and into the humidifier for humidification and circulation of humidified air through the return air duct.

11. The system of claim 7, wherein the humidifier is coupled to the supply air duct and the inline duct fan is connected to the return air duct and the bypass duct, and wherein the inline duct fan is configured to move humidified air from the humidifier through the bypass duct and into the return air duct.

12. The system of claim 6, wherein the processing circuitry is configured to:

receive sensor data indicative of an air humidity within the system;

compare the sensor data to an air humidity setpoint; and

operate the humidifier and the inline duct fan, based on comparing the sensor data to the air humidity setpoint, to humidify air within the system.

13. The system of claim 6, wherein the processing circuitry is configured to:

receive sensor data indicative of an air humidity within the system;

compare the sensor data to an air humidity setpoint;

operate the inline duct fan, based on comparing the sensor data to the air humidity setpoint, to operate the inline duct fan for providing air to the humidifier; and

operate the humidifier, based on operating the inline duct fan, to humidify air within the system.

14. The system of claim 13, further comprising:

a first electrical connection formed between a controller of an HVAC system and a transformer;

a second electrical connection formed between the transformer and the humidifier;

a third electrical connection formed between the humidifier and the inline duct fan; and

a fourth electrical connection formed between the inline duct fan and the controller.

15. The system of claim 14, wherein the second electrical connection is formed between an electrical control valve of the humidifier and the transformer and the third electrical connection is formed between the electrical control valve of the humidifier and the inline duct fan, and wherein the electrical control valve completes the second electrical connection and the third electrical connection when the humidifier operates to provide humidification of air through the system.

16. A method for humidifying air, comprising:

receiving sensor data indicative of an air humidity;

comparing the sensor data to an air humidity setpoint;

operating an inline duct fan, based on comparing the sensor data to the air humidity setpoint, to operate the inline duct fan for providing air to a humidifier; and

operating the humidifier to humidify the air.

17. The method of claim 16, further comprising mounting the inline duct fan to the humidifier and a bypass duct connected to a supply air duct, wherein the humidifier is coupled to a return air duct, and wherein, during operation, the inline duct fan moves air from the supply air duct through the bypass duct and into the humidifier for humidification and circulation of humidified air through the return air duct.

18. The method of claim 16, further comprising mounting the inline duct fan to the humidifier and a bypass duct connected to a return air duct, wherein the humidifier is coupled to a supply air duct, and wherein, during operation, the inline duct fan moves humidified air from the humidifier through a bypass duct and into the return air duct.

19. The method of claim 16, further comprising mounting the inline duct fan to a supply air duct and a bypass duct, wherein the humidifier is coupled to a return air duct and the bypass duct, and wherein, during operation, the inline duct fan moves air from the supply air duct through the bypass duct and into the humidifier for humidification and circulation of humidified air through the return air duct.

20. The method of claim 16, further comprising mounting the inline duct fan to a return air duct and a bypass duct, wherein the humidifier is coupled to a supply air duct and the bypass duct, and wherein, during operation, the inline duct fan moves humidified air from the humidifier through the bypass duct and into the return air duct.