Abstract: An apparatus for reducing discharge pressure includes a compensator reservoir and a compensator line. The compensator line connects the compensator reservoir and a liquid line. The liquid line connects an outdoor heat exchanger and an indoor heat exchanger of a reversible HVAC system. The compensator line includes a connection to the compensator reservoir and a connection to the liquid line. A first expansion device is disposed in the liquid line and configured to only act on refrigerant flowing towards the outdoor heat exchanger. A second expansion device disposed in the liquid line and configured to only act on refrigerant flowing towards the indoor heat exchanger. The compensator is operable to receive refrigerant, driven by pressure, from the HVAC system, and further operable to allow refrigerant to flow back into the HVAC system.

Abstract: Systems and methods are presented for improving stabilization of a heating, ventilating, and air conditioning (HVAC) system. More specifically, the systems and methods include a heat-flow modulator for regulating an exchange of thermal energy between a flow of refrigerant and a sensory bulb. The exchange of thermal energy allows an expansion valve to respond to a refrigerant temperature using an actuator, which is coupled to the sensory bulb. The heat-flow modulator is formed of a body that includes a first contact surface and a second contact surface. The first contact surface is thermally-coupled to a suction line of the HVAC system, which conveys the flow of refrigerant. The second contact surface is thermally-coupled to the sensory bulb. In one instance the heat-flow modulator has variable volume depending on how installed. Other systems and methods are presented. Variable heat-flow modulators are also presented.

Abstract: In various implementations, a request for operation of an air conditioner may be received. The air conditioner may include a cooling mode and/or a dehumidifying mode. In some implementations, a compressor speed for a compressor of the air conditioner may be determined, and which mode(s) of the air conditioner to allow may be determined based at least partially on the determined compressor speed.

Abstract: The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.

Abstract: One aspect presents an controller that comprises a control board, a microprocessor located on and electrically coupled to the control board, and a memory coupled to the microprocessor and located on and electrically coupled to the control board. The controller is configured to receive a trip signal from a refrigerant high pressure sensor and set a maximum heating % demand of the heat pump system based on the trip signal, recalculate a heating % demand based on at least one of the recalculated heating % demand or the maximum heating % demand.

Abstract: The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.

Abstract: One aspect presents a controller that comprises a control board, a microprocessor located on and electrically coupled to the control board, and a memory coupled to the microprocessor and located on and electrically coupled to the control board. The controller is configured to receive an operating parameter signal and recalculate a first maximum heating % demand to a second maximum heating % demand that is greater than the first maximum heating % demand, when a value of the operating parameter signal exceeds a predetermined value, and operate the HP system based on the second maximum heating % demand.

Abstract: In various implementations, a request for operation of an air conditioner may be received. The air conditioner may include a cooling mode and/or a dehumidifying mode. In some implementations, a compressor speed for a compressor of the air conditioner may be determined, and which mode(s) of the air conditioner to allow may be determined based at least partially on the determined compressor speed.

Abstract: The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.

Abstract: One aspect presents a controller that comprises a control board, a microprocessor located on and electrically coupled to the control board, and a memory coupled to the microprocessor and located on and electrically coupled to the control board. The controller is configured to receive an operating parameter signal and recalculate a first maximum heating % demand to a second maximum heating % demand that is greater than the first maximum heating % demand, when a value of the operating parameter signal exceeds a predetermined value, and operate the HP system based on the second maximum heating % demand.

Abstract: The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.

Abstract: The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.

Abstract: A method of initiating a defrost cycle using a controller of a heat pump system includes measuring a temperature of an evaporator coil and determining whether the temperature of the evaporator coil is less than a freezing temperature. Responsive to a determination that the temperature of the evaporator coil is less than the freezing temperature, determining whether a current dew point temperature of air is greater than the temperature of the evaporator coil. Responsive to a determination that the current dew point temperature of air is greater than the temperature of the evaporator coil, calculating a frost-collection rate. Determining whether the frost-collection rate is greater than a frost-collection-rate threshold, and, responsive to a determination that the frost-collection rate is greater than the frost-collection-rate threshold, initiating a defrost cycle.

Abstract: An HVAC system includes an indoor unit having a return air duct and a supply air duct in an enclosed space. The HVAC system includes an outdoor unit having a variable-speed condenser fan. A first temperature sensor is disposed in at least one of the return air duct, the supply air duct, or an enclosed space. A controller is operatively coupled to the first temperature sensor, and the variable-speed condenser fan. The controller is configured to determine whether at least one of over-cooling or over-heating of air in the enclosed space is occurring. Responsive to a determination that at least one of over-cooling or over-heating of air in the enclosed space is occurring, the controller adjusts a speed of the variable-speed condenser fan.

Abstract: The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.

Abstract: A heating, ventilation, and air-conditioning (HVAC) system comprises an outdoor unit with a fan and a coil, and a controller communicatively coupled to the fan and coil. The controller is operable to receive feedback data from the fan, where the feedback data from the fan corresponds to a power and a speed of the fan. The controller is further operable to store a fan model and a plurality of thresholds and determine a virtual sensor measurement, based at least in part upon the feedback data from the fan and the fan model. The controller is operable to determine that the virtual sensor measurement is greater than a frost threshold or a fouling threshold. The controller is finally operable to, in response to determining that the pressure difference is greater than the frost threshold or the fouling threshold, determine a blocked condition on the coil.

Abstract: Systems and methods are described herein for a self-referencing interferometer. The interferometer can comprise an improved spatial phase shifter that reduces the number of components, size and complexity of the spatial phase shifter and maintains a common path for a combined reference beam and signal beam. The self-referencing interferometer further comprises a single mode fiber shunt for filtering the reference beam and further reducing the size of the interferometer. The angle of the reference beam can be tilted before being recombined with the single beam which further simplifies the spatial phase shifting component of the interferometer.

Abstract: Described herein is a system for transmitting an optical signal from a first location to a second location. The system may include first and second mounting fixtures, a reception module, an optical fiber, and a transmission module. The first fixture may define at least a first cavity and a first aperture at the bottom of the cavity. The reception module may be disposed in the cavity, and include a reflector for receiving the optical signal from a first direction through the first aperture and redirecting the optical signal in another direction. The optical fiber may be for receiving the optical signal from the reflector. The second fixture may define at least a second cavity and a second aperture on the side of the cavity. The transmission module may be disposed in the second cavity and direct the optical signal from the optical fiber through the second aperture.

Abstract: Systems and methods are described herein for a self-referencing interferometer. The interferometer can comprise an improved spatial phase shifter that reduces the number of components, size and complexity of the spatial phase shifter and maintains a common path for a combined reference beam and signal beam. The self-referencing interferometer further comprises a single mode fiber shunt for filtering the reference beam and further reducing the size of the interferometer. The angle of the reference beam can be tilted before being recombined with the single beam which further simplifies the spatial phase shifting component of the interferometer.

Abstract: The present invention provides for a system for calibrating operation of a compressor unit in a heating, ventilation, and air conditioning (HVAC) system. A measuring device measures an operating parameter of the HVAC system at a position where the measuring device is mounted on a refrigerant line of the HVAC system. The measuring device switches states when the value of the measured operating parameter reaches a switching value. A controller estimates a value of the first operating parameter at the position where the first measuring device is mounted on the refrigerant line, and the controller determines whether the estimated first operating parameter is within a threshold percentage of the switching value.