Abstract: A system and method of retrofitting a heating, ventilation, air conditioning, and refrigeration system (HVACR) including one or more brazed, soldered, or mechanical connections between refrigerant lines is disclosed. The method includes removing a refrigerant from the HVACR system. The refrigerant that is removed is a non-flammable refrigerant. An enclosure is installed over the one or more brazed, soldered, or mechanical connections between refrigerant lines. A refrigerant is added to the HVACR system. The refrigerant being added has a global warming potential (GWP) that is relatively lower than the refrigerant removed from the HVACR system. The refrigerant being added has a relatively higher flammability than the refrigerant removed from the HVACR system.

Abstract: A system and method of retrofitting a heating, ventilation, air conditioning, and refrigeration system (HVACR) including one or more brazed, soldered, or mechanical connections between refrigerant lines is disclosed. The method includes removing a refrigerant from the HVACR system. The refrigerant that is removed is a non-flammable refrigerant. An enclosure is installed over the one or more brazed, soldered, or mechanical connections between refrigerant lines. A refrigerant is added to the HVACR system. The refrigerant being added has a global warming potential (GWP) that is relatively lower than the refrigerant removed from the HVACR system. The refrigerant being added has a relatively higher flammability than the refrigerant removed from the HVACR system.

Abstract: A system and method of retrofitting a heating, ventilation, air conditioning, and refrigeration system (HVACR) including one or more brazed, soldered, or mechanical connections between refrigerant lines is disclosed. The method includes removing a refrigerant from the HVACR system. The refrigerant that is removed is a non-flammable refrigerant. An enclosure is installed over the one or more brazed, soldered, or mechanical connections between refrigerant lines. A refrigerant is added to the HVACR system. The refrigerant being added has a global warming potential (GWP) that is relatively lower than the refrigerant removed from the HVACR system. The refrigerant being added has a relatively higher flammability than the refrigerant removed from the HVACR system.

Abstract: Methods and systems to measure a volumetric fluid flow rate through a fluid flow passage, such as an air handler of a HVAC system, are described. The system includes an air intake conduit. The air intake conduit includes a partition, an airflow measuring passage through the partition, and an airflow flow-through passage. The partition and the airflow flow-through passage are arranged in a side-by-side fashion. The airflow measuring passage is equipped with an airflow measuring device to measure the air pressure drop in the airflow measuring passage and has a minimal air pressure drop requirement. The air intake conduit has a minimal volumetric air intake requirement. When the air intake conduit has the minimal volumetric air intake, the air pressure drop measured at the airflow measuring passage is at the minimal air pressure drop requirement.

Abstract: A system and method of retrofitting a heating, ventilation, air conditioning, and refrigeration system (HVACR) including one or more brazed, soldered, or mechanical connections between refrigerant lines is disclosed. The method includes removing a refrigerant from the HVACR system. The refrigerant that is removed is a non-flammable refrigerant. An enclosure is installed over the one or more brazed, soldered, or mechanical connections between refrigerant lines. A refrigerant is added to the HVACR system. The refrigerant being added has a global warming potential (GWP) that is relatively lower than the refrigerant removed from the HVACR system. The refrigerant being added has a relatively higher flammability than the refrigerant removed from the HVACR system.

Abstract: Methods and systems to measure a volumetric fluid flow rate through a fluid flow passage, such as an air handler of a HVAC system, are described. The method may include obtaining a flow rate measurement in a measuring section, and calculating a total flow rate based on a correlation between the obtained flow rate measurement and the total flow rate. The method may also include blocking a portion of the fluid flow passage so that when a minimal volumetric fluid flow rate is provided, the flow rate measurement obtained in the measuring section is at about a minimal sensitivity flow rate requirement.

Abstract: Methods and systems to measure a volumetric fluid flow rate through a fluid flow passage, such as an air handler of a HVAC system, are described. The method may include obtaining a flow rate measurement in a measuring section, and calculating a total flow rate based on a correlation between the obtained flow rate measurement and the total flow rate. The method may also include blocking a portion of the fluid flow passage so that when a minimal volumetric fluid flow rate is provided, the flow rate measurement obtained in the measuring section is at about a minimal sensitivity flow rate requirement.

Abstract: Methods and systems to measure a volumetric fluid flow rate through a fluid flow passage, such as an air handler of a HVAC system, are described. The method may include obtaining a flow rate measurement in a measuring section, and calculating a total flow rate based on a correlation between the obtained flow rate measurement and the total flow rate. The method may also include blocking a portion of the fluid flow passage so that when a minimal volumetric fluid flow rate is provided, the flow rate measurement obtained in the measuring section is at about a minimal sensitivity flow rate requirement.

Abstract: Methods and systems to measure a volumetric fluid flow rate through a fluid flow passage, such as an air handler of a HVAC system, are described. The method may include obtaining a flow rate measurement in a measuring section, and calculating a total flow rate based on a correlation between the obtained flow rate measurement and the total flow rate. The method may also include blocking a portion of the fluid flow passage so that when a minimal volumetric fluid flow rate is provided, the flow rate measurement obtained in the measuring section is at about a minimal sensitivity flow rate requirement.

Abstract: Methods and systems to measure a volumetric fluid flow rate through a fluid flow passage, such as an air handler of a HVAC system, are described. The method may include obtaining a flow rate measurement in a measuring section, and calculating a total flow rate based on a correlation between the obtained flow rate measurement and the total flow rate. The method may also include blocking a portion of the fluid flow passage so that when a minimal volumetric fluid flow rate is provided, the flow rate measurement obtained in the measuring section is at about a minimal sensitivity flow rate requirement.

Abstract: A cabinet for air handling equipment includes two similarly sized covers that are each nonsymmetrical about their vertical centerline. Each cover has an original supply or return air duct opening plus space for an alternate opening. The original and alternate openings are of different shapes to accommodate round or rectangular ducts. The two covers can be interchanged with each other and inverted to provide various supply and return air duct configurations.

Abstract: A condensate drain pan. The drain pan comprises a frame supporting a surface; a side outlet in the frame proximal a high point; and a bottom outlet in the surface proximal a low point. The surface is sloped so that the first side drains to the side outlet; the surface is sloped so that the second side drains to the bottom outlet; and the surface is sloped from the high point to the low point.

Abstract: A method of controlling fans in a rooftop air conditioning unit. The method comprises the steps of: determining a measure of compressor operating capacity; calculating an indoor fan speed as a function of that capacity; maintaining a fixed relationship between the indoor fan speed and an outdoor fan speed; and controlling the indoor fan in accordance with the calculated indoor fan speed.

Abstract: An ignitor assembly for a gas combusting power furnace especially designed for both durability and ease of replacement. The ignitor assembly includes a generally elongated ignitor element and a tubular sleeve for slideably, removably mounting the ignitor element generally perpendicular to the burner plate assembly of the furnace. A retaining clip snapably holds the ignitor element within the sleeve. The transverse mounting of the ignitor relative to the burner plate places the ignitor element tip within the combustion plenum, but keeps the lead-in wires of the ignitor on the noncombustion side of the burner plate. The unique mounting arrangement of the ignitor assembly provides maintenance access to the ignitor element without the need to disassemble the burner assembly.

Abstract: A method of operating a controller of an HVAC system comprising the steps of: constantly establishing the validity of each of a plurality of input devices; and reconfiguring the mode of operation of the HVAC system each time the validity of any of the plurality of input devices changes to ensure that the HVAC system operates in the best available mode of operation.

Abstract: A capillary tube assembly having a capillary tube body for connection to a refrigeration system and a tube end cap for accepting a plurality of capillary tubes each of which is identically preformed. The capillary tube assembly is adaptable to different refrigeration systems of varying capacity by utilizing a suitable number of identically preformed capillary tubes together with a suitable tube end cap. The capillary tube assembly is manufactured by preforming identically a suitable number of capillary tubes, preparing a tube end cap with the desired number of apertures and inserting therethrough the capillary tubes, securing the tube end cap to a capillary tube body and reducing the diameter of the tube body to the diameter of the refrigerant supply line of the refrigeration system to which the capillary tube assembly is to be applied.

Abstract: A frameless air handling enclosure is made possible by the use of double-flanged edges on the enclosure's side and bottom panels. The edge configuration provides reinforcement and rigidity to an otherwise flexible panel and also provides a mating surface for fastening the panels together. The enclosure includes an access opening that is covered by a removable access panel having a lining of sound and thermal insulating material. The access panel is installed by first sliding it upward into engagement with a top flange retainer and then sliding it back down into engagement with a bottom flange retainer. Upon engagement with both flange retainers, the lining of insulation is compressed against the perimeter of the access opening. This compression fit not only helps hold the access panel firmly in place but also provides a weathertight seal around the perimeter of the opening.

Abstract: A frameless air handling enclosure is made possible by the use of double-flanged edges on the enclosure's side and bottom panels. The edge configuration provides reinforcement and rigidity to an otherwise flexible panel and also provides a mating surface for fastening the panels together. The enclosure includes an access opening that is covered by a removable access panel having a lining of sound and thermal insulating material. The access panel is installed by first sliding it upward into engagement with a top flange retainer and then sliding it back down into engagement with a bottom flange retainer. Upon engagement with both flange retainers, the lining of insulation is compressed against the perimeter of the access opening. This compression fit not only helps hold the access panel firmly in place but also provides a weathertight seal around the perimeter of the opening.

Abstract: A microprocessor based control for tempering supply air in a multi-stage temperature conditioning system. The temperature conditioning stages are normally controlled in response to a comfort temperature sensor to maintain the zone at a setpoint. However, if a sensor in the supply airstream indicates that the temperature of the supply air is less than a predetermined minimum, the primary control algorithm is overridden and the temperature conditioning stages are controlled to increase the supply air temperature. Tempering the supply air prevents personal discomfort due to excessively cold air being supplied to the zone.