Abstract: An HVAC system is provided. Embodiments of the present disclosure generally relate to heat exchangers having tubing with a reduced diameter compared to traditional systems. In one embodiment, a ducted HVAC system comprises an outdoor heat exchanger with tubing that has an outer diameter of eight millimeters (8 mm) or less and an indoor heat exchanger with tubing that has an outer diameter of nine millimeters (9 mm) or less. Additional systems, devices, and methods are also disclosed.

Abstract: An HVAC system having a fixed orifice expansion device coupled to an evaporator coil is provided. In one embodiment, an expansion device coupled to an evaporator coil includes a flow restrictor and an evaporator inlet manifold. The flow restrictor includes multiple fixed orifices aligned with the refrigerant distribution tubes to restrict flow of refrigerant from the evaporator inlet manifold into the refrigerant distribution tubes through the multiple fixed orifices. Additional systems, devices, and methods are also disclosed.

Abstract: The present disclosure relates to a heating, ventilation, and air conditioning (“HVAC”) system include a supply damper, a return damper, and a defrost damper which are operable to control a supply airflow, a return airflow, and a defrost airflow to flow between a supply duct, a return duct, and an indoor heat exchanger without substantially flowing into and substantially cooling an indoor space. A reheat coil may also warm the supply air flow and a defrost return line may be used to bypass a bi-flow expansion device and an indoor heat exchanger.

Abstract: An HVAC system with an integrated source of outdoor air is provided. In one embodiment, an HVAC system includes an outdoor unit, having a compressor and a heat exchanger, and a ventilation unit to receive and provide outdoor air to a structure. The ventilation unit has a blower, a dehumidifying coil, and a reheat coil installed in a housing. The HVAC system also includes a first electronic expansion valve coupled outside the housing of the ventilation unit to control refrigerant flow into the dehumidifying coil and a second electronic expansion valve coupled outside the housing of the ventilation unit to control refrigerant flow into the reheat coil. An electronic expansion valve controller is connected to control operation of the first electronic expansion valve and the second electronic expansion valve. Additional systems, devices, and methods are also disclosed.

Abstract: An HVAC system is provided. Embodiments of the present disclosure generally relate to heat exchangers having tubing with a reduced diameter compared to traditional systems. In one embodiment, a ducted HVAC system comprises an outdoor heat exchanger with tubing that has an outer diameter of eight millimeters (8 mm) or less and an indoor heat exchanger with tubing that has an outer diameter of nine millimeters (9 mm) or less. Additional systems, devices, and methods are also disclosed.

Abstract: An authentication method and system for an HVAC system are provided. Embodiments of the present disclosure generally relate to an access-control or authentication system for an HVAC system, in which access to certain functions of the HVAC system is conditioned on a user performing certain basic operational instructions for the HVAC system in a provided sequence, thereby providing evidence that the user has authorization to access and operate the HVAC system wirelessly.

Abstract: An authentication method and system for an HVAC system are provided. Embodiments of the present disclosure generally relate to an access-control or authentication system for an HVAC system, in which access to certain functions of the HVAC system is conditioned on a user performing certain basic operational instructions for the HVAC system in a provided sequence, thereby providing evidence that the user has authorization to access and operate the HVAC system wirelessly.

Abstract: The present disclosure relates to a multi-circuit heating, ventilation, and air conditioning (“HVAC”) system for use with a first refrigerant in a first refrigerant circuit and a second refrigerant in a second refrigerant circuit. The second refrigerant circuit is fluidically isolated from the first refrigerant circuit. Additionally, a first sensor is operable to detect a leak of at least one of the first and second refrigerants or is operable to measure temperature or pressure from the first refrigerant circuit or the second refrigerant. The multi-circuit HVAC system further including a controller programmed to receive the measurement from the sensor to identify the circuit or circuits that are leaking, to turn off operation of the leaking circuit or circuits, and if only one circuit is leaking, operate only the other of the circuits.

Abstract: The present disclosure relates to a heating, ventilation, and air conditioning (“HVAC”) system include a supply damper, a return damper, and a defrost damper which are operable to control a supply airflow, a return airflow, and a defrost airflow to flow between a supply duct, a return duct, and an indoor heat exchanger without substantially flowing into and substantially cooling an indoor space. A reheat coil may also warm the supply air flow and a defrost return line may be used to bypass a bi-flow expansion device and an indoor heat exchanger.

Abstract: A heating, ventilation, and air-conditioning (HVAC) system that includes an outdoor heat exchanger (HX) and outdoor fans. The outdoor fans are arranged in either an in-line configuration or a staggered configuration to satisfy one or more requirements to optimize the airflow across the outdoor HXs.

Abstract: A heating, ventilation, and air-conditioning (HVAC) system that includes an outdoor heat exchanger (HX) and outdoor fans. The outdoor fans are arranged in either an in-line configuration or a staggered configuration to satisfy one or more requirements to optimize the airflow across the outdoor HXs.

Abstract: The present disclosure relates to a heating, ventilation, and air conditioning (HVAC) system, and more particularly a method of detecting and mitigating refrigerant leaks in an HVAC system. The HVAC system includes a leak detection system for detecting a leak of the refrigerant from the refrigerant circuit. The leak detection system includes a collection chamber locatable proximate a component of the HVAC system. The leak detection system also includes a sensor assembly including an enclosure comprising a sensor and a fan. The leak detection system also includes a flowline connecting the collection chamber with the sensor assembly such that the sensor assembly may be located away from the collection chamber and the component. The fan is operable to induce fluid flow from the collection chamber into the sensor assembly and the sensor is operable to analyze the fluid flow and detect a leak of the refrigerant from the component.

Abstract: A furnace assembly for use with a gas fuel that includes a cabinet and a burner located in the cabinet that is operable to ignite the gas fuel. The furnace also includes a heat exchanger assembly in communication with the burner and open to receiving the ignited gas fuel, the heat exchanger assembly including tubes. Each tube includes a first section with an inlet, a horizontal section having a first internal diameter, and a vertical section. Each tube also includes a second section extending from the first section and having a second internal diameter less than the first internal dimeter. The second section also includes a serpentine flow path up and down in the vertical direction and an outlet. The gas fuel entering a tube stays in the tube until flowing out of the tube. The furnace also includes a blower operable to move air through the cabinet and over the heat exchanger assembly.

Abstract: An HVAC system with a refrigerant gas sensor is provided. In one embodiment, an HVAC system includes a heat exchanger coil installed within a housing. The heat exchanger coil is operable to exchange heat with air in the housing via a refrigerant passing through the heat exchanger coil. The system also includes an HVAC sensor assembly installed within the housing. The HVAC sensor assembly includes a refrigerant gas sensor and an orientation sensor positioned to detect an orientation of the refrigerant gas sensor. The HVAC system may also or instead include a position sensor to detect the position of the refrigerant gas sensor within the system. Additional systems, devices, and methods are also disclosed.

Abstract: An HVAC system is provided. Embodiments of the present disclosure generally relate to heat exchangers having tubing with a reduced diameter compared to traditional systems. In one embodiment, a ducted HVAC system comprises an outdoor heat exchanger with tubing that has an outer diameter of eight millimeters (8 mm) or less and an indoor heat exchanger with tubing that has an outer diameter of nine millimeters (9 mm) or less. Additional systems, devices, and methods are also disclosed.

Abstract: A reversible heat pump system with one bi-flow expansion device. A four-way valve in the refrigerant circuit may be configured in either a cooling mode or a heating mode. In the cooling mode, a compressor is operable to flow a refrigerant out a compressor outlet and through the bi-flow expansion device in a first direction. In the heating mode, the compressor is operable to flow the refrigerant out the compressor outlet and through the bi-flow expansion device in a second direction, opposite the first direction. Thus, only one thermal expansion device is needed for a reversible heat pump heating, ventilation, and air conditioning (HVAC) system without the need for bypass lines and check valves around the bi-flow expansion device. Further, if an accumulator is included before the compressor, the bi-flow expansion device may be controlled to store at least some refrigerant in the accumulator, thus allowing the evaporator superheat to be lower than if the accumulator were not used.

Abstract: A heating, ventilation, and air conditioning (HVAC) system includes one or more compressors, one or more outdoor heat exchangers, and one or more indoor heat exchangers. The HVAC system also includes a base pan on which the one or more compressors are mounted. The base pan includes a base level and one or more tier levels higher than the base level. The distance from any point on a perimeter of the first-tier level to a nearest point on a perimeter of the base level is based on the smallest bolt circle diameter of the one or more compressors mounted on the base pan. Also, the perimeter lengths of the tier levels are based on a percentage of the base level perimeter length.

Abstract: A drain pan and a method for fabricating a drain pan for use with an air conditioner, the drain pan having a plastic drain having plastic threads, with an insert disposed within the plastic drain to prevent the fracturing of the plastic threads when a steel pipe is threaded into the plastic drain. The insert may be a metal insert.

Abstract: A warm air furnace and method for securing a thermostat to a wall of a warm air furnace utilizes a thermostat mounting flange which has its ends forced inwardly into openings formed in a wall of the furnace, and the thermostat may be secured to the wall of the furnace without the use of screws.

Abstract: A warm air furnace and method for securing a thermostat to a wall of a warm air furnace utilizes a thermostat mounting flange which has its ends forced inwardly into openings formed in a wall of the furnace, and the thermostat may be secured to the wall of the furnace without the use of screws.