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: The present invention provides a heating, ventilation, and air-conditioning (HVAC) system using an A2L refrigerant and a method of installing the HVAC system in a building. The HVAC system includes an indoor unit having a heat exchanger that uses an A2L refrigerant, a blower, an outdoor unit, an A2L control board, and one or more A2L sensors configured to detect an amount of A2L refrigerant. In one or more embodiments, the indoor unit is electrically coupled to the blower, the A2L control board, and the outdoor unit. Also, in one or more embodiments, the A2L control board is also electrically coupled to the blower and the one or more A2L sensors.

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: A system and method for controlling the air temperature in a building. The system includes one or more equipment of a heating ventilation and air-conditioning (HVAC) system, at least one of one or more thermostats or one or more temperature sensors, and a controller. The controller includes a communication module to exchange data with one or more devices and an equipment interface configured to communicate control signals to the one or more equipment. The controller is configured to obtain as user input a target rate of change (ROC) of air temperature in the building and operate the one or more equipment of the HVAC system to achieve the target ROC. The controller operates the one or more equipment at an initial capacity and adjusts the capacity of the one or more equipment to achieve the target ROC of the air temperature in the building.

Abstract: A system and method for controlling the air temperature of a building using a control plan based on a target time. The system includes a controller which may be connected to a number of indoor and outdoor heating ventilation and air-conditioning units. The system may include a thermostat. The system may also operate without a thermostat. The method includes determining a control plan to reach a desired temperature in a target time. The method also includes updating the plan by comparing the actual time to reach the desired temperature with the target time.

Abstract: A system and method for controlling the air temperature of a building using a control plan based on a target time. The system includes a controller which may be connected to a number of indoor and outdoor heating ventilation and air-conditioning units. The system may include a thermostat. The system may also operate without a thermostat. The method includes determining a control plan to reach a desired temperature in a target time. The method also includes updating the plan by comparing the actual time to reach the desired temperature with the target time.

Abstract: A system and method for controlling indoor climate of a building. The system includes one or more equipment of a heating ventilation and air-conditioning (HVAC) system, a thermostat configured to wirelessly transmit operational data and a controller communicatively coupled to the one or more equipment and the thermostat. The controller includes a communication module configured to exchange the operational data with the thermostat and an equipment interface configured to communicate control signals to the one or more equipment to control operation of the one or more equipment. The controller is configured to receive the operational data wirelessly transmitted from the thermostat using the communication module, determine based on the operational data a control plan to operate the one or more equipment of the HVAC system, and operate the one or more equipment of the HVAC system based on the control plan.

Abstract: A system and method for controlling the air temperature of a building using a control plan based on a target time. The system includes a controller which may be connected to a number of indoor and outdoor heating ventilation and air-conditioning units. The system may include a thermostat. The system may also operate without a thermostat. The method includes determining a control plan to reach a desired temperature in a target time. The method also includes updating the plan by comparing the actual time to reach the desired temperature with the target time.

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.