ROOF VENTILATION SYSTEM
This application relates to ventilation systems, more particularly to a roof vent with one or more fan assemblies and/or an associated solar panel. The roof vent has an upper member including at least one opening that permits air flow between regions above and below the upper member. The vent further includes a lower member in fluid communication with the region below the upper member. The lower member includes a second opening permitting air flow between a region below the roof deck and the region below the upper member. The lower member further includes a fan configured to generate air flow through the second opening, wherein the fan resides in a fan housing positioned below the second opening.
This application is a U.S. National Stage application, under 35 U.S.C. 371, of International Application No. PCT/US2009/035346, filed Feb. 26, 2009, which claims the benefit under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/067,280, filed Feb. 26, 2008, entitled “Roof Ventilation System,” the entire disclosure of which is hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates to ventilation systems, more particularly to active ventilation systems that can be used in a roof of a building.
2. Description of the Related Art
Ventilation of a building has numerous benefits for both the building and its occupants. For example, ventilation of an attic space can prevent the attic's temperature from rising to undesirable levels, which also reduces the cost of cooling the interior living space of the building. In addition, increased ventilation in an attic space tends to reduce the humidity within the attic, which can prolong the life of lumber used in the building's framing and elsewhere by diminishing the incidence of mold and dry-rot. Moreover, ventilation promotes a more healthful environment for residents of the building by encouraging the introduction of fresh, outside air. These and other benefits of ventilation tend to compound as ventilation increases. That is, the greater the flow rate of air that is vented through the building, the greater the benefits.
Consequently, power devices such as fans have been employed in active ventilation systems to force greater air flow into and out of an attic space. One drawback of some such active ventilation systems is their consumption of electricity from the local power grid. With increasing energy costs and heightening concerns for environmental impacts, devices that can operate with little or no electricity from the power grid are becoming more attractive.
Another consideration is ease of installation. Some ventilation systems require a relatively lengthy and confusing installation procedure, which may involve the use of more than one kind of tradesperson. Such systems are more expensive to install and may suffer failures during operation due to faulty installation. Accordingly, a ventilation system that is relatively easy to install and operate is desirable.
A ventilation system that improves on one or more of these concerns is needed.
SUMMARY OF THE INVENTIONEmbodiments of the roof ventilation systems of the present invention have several features, no single one of which is solely responsible for their desirable attributes. Without limiting the scope of this invention, its more prominent features will now be discussed briefly. However, not all of the following features are necessary to achieve the advantages of the system. Therefore, none of the following features should be viewed as limiting. After considering this discussion, and particularly after reading the section entitled “Detailed Description of the Preferred Embodiments,” one will understand how the features of the preferred embodiments provide advantages over prior art.
The presently disclosed embodiments seek to address the issues discussed above by utilizing a solar panel to power a fan associated with a roof vent system. The fan can be positioned in the attic space in order to accommodate fans with larger blades, capable of moving greater amounts of air. In one embodiment, the fan housing can be sized and shaped to simplify installation, such as by employing a substantially cylindrical housing that is generally free of protrusions. In other embodiments, the fan housing has a substantially frustoconical shape, facilitating the use of a relatively larger fan without necessitating a large hole in the roof. Some embodiments include a one-piece vent, which can be of particular utility in a composition roof. Other embodiments can utilize an upper vent having an appearance that mimics one or more tiles, for use in a tile roof.
In accordance with one embodiment, a roof vent is provided. The vent includes an upper member comprising a first opening that permits air flow between regions above and below the upper member. The vent further includes a lower member in fluid communication with the region below the upper member. The lower member includes a second opening permitting air flow between a region below the roof and the region below the upper member. The lower member further includes a fan configured to generate air flow through the second opening. The fan resides in a fan housing extending downwardly from the second opening to a third opening below the roof. The fan housing has a first lateral cross sectional area at the second opening and a second lateral cross sectional area at the third opening. The second lateral cross sectional area is greater than the first lateral cross sectional area.
In accordance with another embodiment, a method of installing a roof vent comprising a fan is provided. The method includes providing an opening in a roof deck. A roof vent having a lower member and an upper member is provided, the lower member having a downwardly extending fan housing. A portion of the fan housing is inserted through the opening. A base portion of the lower member of the roof vent is permitted to rest above the roof deck while the fan housing is attached to the base portion. The method further includes providing a layer of tiles positioned above the roof deck, such that a batten cavity is defined between the roof deck and the layer of tiles. The upper member is positioned within the layer of tiles, such that the upper member replaces one or more of the tiles. The positioning of the upper member comprises displacing the upper member from the opening in the roof deck, so that air can flow along a flow path extending from a space below the roof, through the batten cavity and along the roof, and through the upper member of the vent.
In accordance with another embodiment, a roof vent is provided. The vent includes an upper member including a first opening that permits air flow between regions above and below the upper member. The vent further includes a lower member in fluid communication with the region below the upper member. The lower member includes a second opening permitting air flow between a region below the roof and the region below the upper member. The lower member further includes at least two fans configured to generate air flow through the second opening. The fans reside in a fan housing positioned below the second opening.
In accordance with still another embodiment, a roof ventilation system is provided. The ventilation system comprises a lower vent member, an upper vent member, a solar panel, a first actuator, and a controller. The lower vent member has an opening and a base portion extending outwardly from the opening. The base portion is adapted to rest upon a roof deck approximately at an opening in the roof deck, such that air can flow through the roof deck and vent member by flowing through the roof deck opening and the vent member opening. The upper vent member is configured to be secured to the lower vent member or to a field of roof cover elements above the roof deck. The solar panel is secured to the upper vent member, and the first actuator configured to rotate the solar panel about a first axis. The controller is configured to electronically control the first actuator to rotate the solar panel about the first axis.
In accordance with still another embodiment, a roof vent is provided. The vent includes an upper member including a first opening that permits air flow between regions above and below the upper member. The vent further includes a lower member in fluid communication with the region below the upper member. The lower member includes a second opening permitting air flow between a region below the roof and the region below the upper member. The lower member further includes a fan configured to generate air flow through the second opening. The fan resides in a substantially cylindrical fan housing positioned below the second opening. The fan housing is substantially free of protrusions extending laterally from the outer surface of the housing.
All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.
The appended drawings are schematic, not necessarily drawn to scale, and are meant to illustrate and not to limit embodiments of the invention.
The upper member 16 includes a solar panel 20, such as a photovoltaic (PV) panel. The solar panel 20 can be in electrical communication with and provide power to a fan assembly 38, and/or one or more control systems, as described further below. In some embodiments, the upper member 16 can include a bracket 60 that selectively receives the solar panel 20, thus facilitating maintenance and/or replacement of the solar panel 20. The bracket 60 may have grooves sized and shaped to slidably receive the solar panel 20. The bracket 60 shown in
In other embodiments, the bracket 60 may be movable, such as by rotating the solar panel 20 about at least one and preferably two axes, such that solar panel 20 can face substantially any direction.
Bracket 60 can also comprise a rotatable connection 22 for rotating a section of bracket 60 and panel 20 an angle θ2 about a second axis 34. The second axis 34 can extend approximately perpendicular to the roof field, and preferably, can extend approximately perpendicular to axis 29. A skilled artisan will understand that the rotatable connection 22 can comprise any element for rotating the solar panel 20 about the second axis 34, such as a bearing or a rotatable table.
The rotation of solar panel 20 about the first axis 29 and/or the second axis 34 allows a user to move solar panel 20 relative to the position of the sun. Moving solar panel 20 allows a user to adjust the amount of solar energy received by the solar panel 20. For example, a user may adjust the solar panel 20 to directly face the sun. Solar panel 20 can be moved to account for the sun's position due to the time of day and/or the time of year. In some embodiments, solar panel 20 can be moved to a retracted position in which it is substantially parallel with and close to the roof and/or upper member 16 (
In some embodiments, solar panel 20 and bracket 60 can be moved manually by using the hinge 27 and/or rotatable connection 22, such as when a user grasps solar panel 20 and/or bracket 60 by hand or with a tool. In other embodiments, a first actuator 41 and second actuator 42 may be provided to move solar panel 20 and bracket 60. For example, each actuator 41, 42 can comprise an electric actuator with a motor controllable by a control system. Using a control system and electric actuators to move solar panel 20 and bracket 60 can increase the efficiency with which the solar panel 20 receives solar energy from the sun, because electric actuators can be activated more easily and frequently without the need to climb onto the roof, so as to track the position of the sun as it moves with respect to the panel 20.
In an embodiment, control system 40 can comprise one or more sensors 44 that send electronic signals, or feedback, to controller 43. Sensor 44 can comprise many types, such as an optical sensor that can sense the position of the sun relative to the position of sensor 44. In this embodiment, controller 43 can be configured to analyze the incoming signal sent from sensor 44 and adjust the outgoing signal to actuator 41 and/or actuator 42 accordingly. As such, actuator 41 and/or actuator 42 can move to a desired position in response to the signal received by controller 43 from sensor 44. In a preferred embodiment, sensor 44 is positioned on solar panel 20 or bracket 60, forming a closed loop system for controlling the position of solar panel 20. In this embodiment, actuator 41 and/or actuator 42 can move solar panel 20 to follow the position of the sun or, alternatively, to move solar panel 20 to a retracted position, based on the signals that controller 43 receives from sensor 44.
In certain embodiments, sensor 44 can be configured to sense sunlight intensity or windspeed velocity. When sensor 44 comprises a sunlight intensity sensor, if the sunlight intensity moves above or below a predetermined threshold, sensor 44 can send a signal triggering controller 43 to move solar panel 20 from or to a retracted position, respectively. For example, it may be desirable to retract the solar panel if the sunlight intensity is low. Similarly, when sensor 44 comprises a windspeed velocity sensor, if the windspeed moves above or below a predetermined threshold, sensor 44 can send a signal triggering controller 43 to move solar panel 20 to or from a retracted position, respectively. For example, it may be desirable to retract the solar panel 20 at high wind speeds, to prevent damage thereto. A skilled artisan will understand that more than one sensor 44 can be used, such as embodiments in which multiple sensed conditions (e.g., sun position, sunlight intensity, wind speed) are used as inputs to the controller 43.
In another embodiment, actuator 41 and/or actuator 42 can move solar panel 20 to correspond to one or more desired predetermined position(s). The desired predetermined position(s) can comprise a retracted position, or a plurality of different positions to which solar panel 20 can be moved at different times to optimize the solar energy it receives from the sun, as described above. The desired predetermined position(s) can be stored in a data storage system 45. Controller 43 can adjust its output signals so that actuator 41 and/or actuator 42 move solar panel 20 to predetermined positions stored in data storage system 45. In an embodiment, controller 43 can adjust its signal to move actuator 41 and/or actuator 42 in a sequence of predetermined positions, separated by time intervals by using the timer 46. Data storage 45 can comprise any data storage system known in the art, such as a hard drive integrated with controller 43, or separate from controller 43. The predetermined positions can be paired with corresponding times of day and/or year at which the predetermined positions will efficiently orient the solar panel 20 to receive solar energy from the sun, and the controller 43 can be configured to move the solar panel 20 to each predetermined position at its corresponding time of day and/or year.
In another embodiment, data storage system 45 comprises sun position data that controller 43 uses to adjust its output signals so that actuator 41 and/or actuator 42 move solar panel 20 to face the sun throughout the day and/or the year, as described above. For example, the sun position data may comprise empirically observed information detailing the sun's position relative to the Earth, for a variety of times of the day and/or year.
The accuracy in using the sun position data stored in storage system 45 to move solar panel 20 may be related to the geographic position or the orientation of solar panel 20. Thus, it may be desirable for controller 43 to receive the solar panel's geographic position and/or orientation. In some embodiments, the controller 43 is configured to use the actuators 41 and 42 to move the solar panel 20 to an optimal position for receiving solar energy, based at least on (1) the position and orientation of the solar panel in its installed, retracted position, and (2) the sun position data in the data storage system 45. In one embodiment, the control system includes a user interface (e.g., keypad, touch screen, and/or network interface) for receiving the solar panel's position (e.g., longitude, latitude, city, zip code, state, country, street address, or the like) and orientation (e.g., the direction in which it faces, its angle with respect to the local horizon, north, south, east, west designations, etc.) in the panel's installed, retracted position. In another embodiment, the control system includes a GPS or like device for determining the solar panel's location, and other sensors (e.g., accelerometers) for determining the panel's orientation.
A skilled artisan will appreciate that certain embodiments of system 40 do not include all the components shown in
System 40 can further comprise a battery 25. Referring to both
Control systems for controlling fans in vent systems using batteries powered by rooftop solar panels are disclosed in U.S. application Ser. No. 11/736,498, entitled “AUTOMATIC ROOF VENTILATION SYSTEM,” filed Apr. 17, 2007, and the publication of the same application in U.S. Patent Application Publication No. 2007/0243820, published Oct. 18, 2007, the disclosures of which are hereby incorporated by reference herein in their entireties. In other embodiments, the solar panel 20 may provide power to the local power grid. A skilled artisan will appreciate that fan assembly 38 can comprise either an AC or a DC system, regardless of whether the ventilation system includes battery 25. For example, an AC fan can be used with the battery 25 if the power is provided after an inverter in the system (not shown). This can improve the efficiency of the system. Additionally, using an AC fan may allow the roof ventilation system to use certain commercially available solar panel systems, such as the photovoltaic system marketed by Eagle Roofing Systems as the SolarSave™ integrated panel system. A skilled artisan will understand that the embodiments illustrated in
As shown in
Referring again to
Extending downwardly from the hole 21 in the top portion 19 is the fan housing 30. Positioning the fan housing 30 below the roof deck in the attic space advantageously permits a larger size fan assembly 38, as compared to systems in which a fan is positioned above the roof deck but below a top portion of the vent. In such systems, the size of the fan is constrained by the limited space available between the roof deck and the top portion of the vent. The larger fan assembly 38 afforded by embodiments disclosed herein are capable of moving a greater volume of air per minute. This increased air flow capacity can enhance the performance of the roof vent 10. For convenience and simplicity, this application refers to the space beneath the roof deck as an attic space. However, skilled artisans will appreciate that embodiments can be used in buildings that do not have attics, such as buildings with vaulted ceilings.
With continued reference to
In some embodiments, the size of the hole 21 of the top portion 19, and the lateral cross section of the cylindrical fan housing 30, is less than or substantially equal to 144 square inches, or an alternative size limit imposed by a building code. Building codes in some areas require extra structural enhancements, sometimes called blocking, when a hole in the roof exceeds a certain value, such as 144 square inches. Blocking may require the work of a workman in a different trade than the person ordinarily tasked with installing roof vents. The involvement of another trade and another workman can delay and increase the expense of installation. Accordingly, it may be preferable to employ a cylindrical fan housing 30 with a cross sectional area less than or substantially equal to a size required under a building code (such as 144 sq. in.), in order to avoid the need for blocking. A smaller hole in the roof deck can be desirable for other reasons as well, including to preserve the structural integrity of the roof and building against seismic events, and to guard against wind shear and lateral uplift.
In certain applications, greater air flow may be required than can be accommodated using a roof vent 10 with a single cylindrical fan housing 30 as described above and shown in
Another embodiment of a lower member 18 is shown in
A skilled artisan will understand that it may be desired to employ two or more fans (e.g., as shown in
Skilled artisans will appreciate that many other variations are also possible. For example, a cylindrical fan housing 30 may be employed in which the cross sectional area is greater than a size limit imposed by a building code (such as 144 sq. in.), wherein blocking is also carried out. Other configurations may employ a fan housing 30 with an increasing (e.g., gradually increasing) cross section from top to bottom in some shape other than a frustocone, such as the shape of a layer cake or an inverted funnel. Further, a roof vent with two or more fans as described above is possible for other ventilation designs, such as the integrated vent embodiments described below and shown in FIGS. 4 and 10-13.
The upper portion of the vent can be configured to selectively receive a solar panel 20. As shown more clearly in
In some embodiments, it may be desirable to position the upper member 16 in a different portion of the roof than the lower member 18. For example, the shadow cast by a tree may hinder the performance of the solar panel 20 in certain areas of the roof. In such cases, the upper member 16 can be offset (i.e., displaced) from the position of the lower member 18, such as illustrated in
In an alternative embodiment, only the solar panel 20 is offset from the lower vent member 18. In such an embodiment, the solar panel 20 is preferably still hardwired to the fan assembly 38 and/or other elements of the control system of
A skilled artisan will also appreciate that some air flow may be permitted between the various tiles 54, such that some of the air leaves the batten cavity 52 without flowing through the upper member 16. Tile roofs employing tiles of this nature are shown and described in U.S. Pat. No. 6,491,579, the entirety of which is hereby incorporated herein by reference. Further, although the foregoing description describes a primary direction of air flow in some embodiments, other air currents may also be present in the batten cavity 52, including air flow in a reverse direction from that described above. In some embodiments, the tiles 54 overlying the lower member 18 can be replaced with a solar panel or an array of solar panels. In such embodiments, the air flow along the underside of the panels between the upper member 16 and the lower member 18 can advantageously aid in the cooling of the solar panels, thereby preventing overheating of the panels and enhancing their energy collection performance.
Offsetting the upper and lower members 16, 18 can have other performance advantages. For example, it has been found that offsetting can help to prevent backloading of the vent. Backloading occurs when unusual conditions, such as strong winds or violent storms, force air to flow through a vent system in a direction opposite from the direction for which the vent system was designed. Backloading can be particularly problematic in an active vent system because the reversed air flow can cause the fan to reverse the direction in which it is driven, potentially leading to severe mechanical damage or failure.
Note that the upper member 16 can be shaped and/or decorated to simulate the appearance of many different types of tiles as described above. The upper member 16 in
In use, the vents 6, 7 in this arrangement promote air flow through the building as indicated by the arrow 8. That is, air tends to flow into the building (e.g., into an attic or crawlspace of the building or into an area below a vaulted ceiling defined by the roof fields 3) through the vents 7, and air tends to exit the building through the vents 6. The roof can also have a batten cavity, as described above, through which air may also flow. This airflow can be provided without fan assemblies in vents 6, 7, such as from the thermal effects of air rising through the attic, along the vaulted ceiling, or through the battens and/or tiles, or through the effect of wind blowing across the roof 2 and ridge 4. The fan assemblies as described above can also be used in vents 6, 7 to increase these natural thermal and wind effects. In some embodiments, fan assemblies 38 are provided in the vents 6 but not the vents 7. In some embodiments, fan assemblies 38 are provided in the vents 6 and 7, wherein the fan assemblies in the vents 7 are configured to draw air into the building, and the fan assemblies in the vents 6 are configured to exhaust air from the building.
Although the invention has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and obvious modifications and equivalents thereof. Accordingly, the invention is not intended to be limited by the specific disclosures of preferred embodiments herein.
Claims
1. A roof vent, comprising:
- an upper member comprising a first opening that permits air flow between regions above and below the upper member; and
- a lower member in fluid communication with the region below the upper member, the lower member comprising: a second opening permitting air flow between a region below the roof and the region below the upper member; and a fan configured to generate air flow through the second opening, wherein the fan resides in a fan housing extending downwardly from the second opening to a third opening below the roof, the fan housing having a first lateral cross sectional area at the second opening and a second lateral cross sectional area at the third opening, wherein the second lateral cross sectional area is greater than the first lateral cross sectional area.
2. The roof vent of claim 1, wherein the upper and lower members form an integrated vent.
3. The roof vent of claim 1, wherein the upper member is configured to simulate an appearance of one or more roof tiles.
4. The roof vent of claim 1, wherein the upper member is laterally displaced with respect to the lower member.
5. The roof vent of claim 1, further comprising a solar panel in electrical communication with the fan.
6. The roof vent of claim 5, further comprising a battery in electrical communication with the solar panel and the fan, the battery being configured to store power from the solar panel for use by the fan.
7. The roof vent of claim 1, further comprising a bracket for selectively receiving a solar panel.
8. The roof vent of claim 7, wherein the bracket includes at least one rotatable axis to alter the orientation of the solar panel relative to the direction of the sun.
9. The roof vent of claim 1, wherein the fan housing has a substantially frustoconical shape.
10. The roof vent of claim 1, wherein the first lateral cross sectional area is less than or substantially equal to 144 sq. in.
11. (canceled)
12. (canceled)
13. (canceled)
14. (canceled)
15. (canceled)
16. (canceled)
17. A roof vent, comprising:
- an upper member comprising a first opening that permits air flow between regions above and below the upper member; and
- a lower member in fluid communication with the region below the upper member, the lower member comprising: a second opening permitting air flow between a region below the roof and the region below the upper member; and at least two fans configured to generate air flow through the second opening, wherein the fans reside in a fan housing positioned below the second opening, the fan housing extending downwardly from the second opening, the fan housing having a first lateral cross sectional area at the second opening and a second lateral cross sectional area at a bottom end of the fan housing, wherein the second lateral cross-sectional area is greater than the first lateral cross sectional area.
18. (canceled)
19. A roof ventilation system, comprising:
- a lower vent member having an opening and a base portion extending outwardly from the opening, the base portion adapted to rest upon a roof deck approximately at an opening in the roof deck, such that air can flow through the roof deck and vent member by flowing through the roof deck opening and the vent member opening;
- an upper vent member configured to be secured to the lower vent member or to a field of roof cover elements above the roof deck;
- a solar panel secured to the upper vent member;
- a first actuator configured to rotate the solar panel about a first axis;
- a second actuator configured to rotate the solar panel about a second axis that is substantially transverse with respect to the first axis;
- a controller configured to electronically control the first actuator to rotate the solar panel about the first axis; and
- a data storage system in electronic communication with the controller, the data storage system storing position data that the controller uses to operate the first and second actuators to move the solar panel to face the sun at a plurality of different times, the position data based on empirical observation of the sun's position relative to the Earth.
20. (canceled)
21. The roof ventilation system of claim 19, further comprising a sensor in electronic communication with the controller, the sensor configured to sense at least one environmental condition, wherein the controller is configured to control the first and/or second actuator in response to an incoming signal from the sensor.
22. The roof ventilation system of claim 21, wherein the at least one environmental condition comprises a position of the sun relative to the solar panel.
23. The roof ventilation system of claim 21, wherein the at least one environmental condition comprises sunlight intensity.
24. The roof ventilation system of claim 21, wherein the at least one environmental condition comprises wind speed.
25. The roof ventilation system of claim 19, wherein the controller is configured to control the first actuator so as to move the solar panel to a retracted position if an amount or rate of power collected by the solar panel is less than a predetermined threshold.
26. The roof ventilation system of claim 19, wherein the data storage system stores predetermined positions of the solar panel, wherein the controller is configured to control the first and second actuator to selectively move the solar panel to the predetermined positions.
27. The roof ventilation system of claim 19, further comprising a fan assembly secured with respect to one of the vent members, the fan assembly configured to receive electrical power from the solar panel.
28. The roof ventilation system of claim 27, further comprising a battery configured to receive electrical power from the solar panel.
29. The roof ventilation system of claim 19, wherein a position of the upper vent member is offset from a position of the lower vent member when both vent members are installed in a roof.
30. The roof ventilation system of claim 19, wherein the upper vent member is secured to the lower vent member.
31. The roof ventilation system of claim 19, wherein the roof cover elements comprise roof tiles, the upper vent member replacing one or more tiles in a field of the roof tiles, the upper vent member simulating an appearance of the roof tiles.
32. (canceled)
33. (canceled)
34. The roof ventilation system of claim 19, further comprising a timer that the controller uses to move the solar panel at specific times or time intervals.
Type: Application
Filed: Feb 26, 2009
Publication Date: Dec 30, 2010
Inventor: Gregory S. Daniels (Santa Rosa, CA)
Application Number: 12/918,799
International Classification: F24F 7/02 (20060101); F24F 7/007 (20060101);