Abstract: An apparatus includes a compressor, a first heat exchanger, a reheater, a first valve, a second heat exchanger, a four-way valve, a cap tube, and a blower. The compressor compresses a refrigerant. The blower moves air proximate the second heat exchanger to the reheater. During a cooling mode of operation, the four-way valve is configured to direct refrigerant from the first heat exchanger to the compressor; the compressor compresses the refrigerant received from the first heat exchanger; and the cap tube is configured to allow refrigerant to bypass the reheater.

Abstract: An apparatus includes first and second microchannel heat exchangers and first and second pipes. The first heat exchanger includes a first inlet, a second inlet, a first tube, a second tube, a first outlet, and a second outlet. Refrigerant at the first inlet is directed through the first tube to the first outlet and the first pipe. Refrigerant at the second inlet is directed through the second tube to the second outlet and the second pipe. The second heat exchanger includes a third inlet, a fourth inlet, a third tube, a fourth tube, a third outlet, and a fourth outlet. The third inlet directs refrigerant from the first pipe through the third tube towards the third outlet. The fourth inlet directs the refrigerant from the second pipe through the fourth tube towards the fourth outlet. The first pipe overlaps the second pipe between the two heat exchangers.

Abstract: An apparatus includes a compressor, a first heat exchanger, a reheater, a first valve, a second heat exchanger, a four-way valve, a cap tube, and a blower. The compressor compresses a refrigerant. The blower moves air proximate the second heat exchanger to the reheater. During a heating mode of operation, the four-way valve is configured to direct refrigerant from the compressor to the second heat exchanger; the second heat exchanger is configured to use the refrigerant from the compressor to heat air proximate the second heat exchanger; and the cap tube is configured to allow refrigerant to bypass the reheater.

Abstract: A metering device may automatically control fluid flow through a valve. A control system may alter the automatic control of a metering device. In some implementations, a predetermined event may occur to alter the automatic control of the metering device.

Abstract: A system comprising a compressor, a first valve coupled to the compressor and coupled to a first coil, a first expansion valve coupled to the first coil, a second coil, and a second expansion valve. The second expansion valve coupled to a third coil, a second valve coupled to the compressor and the third coil. A controller operable to operate the first valve, the first expansion valve, the second expansion valve, and the second valve. The second coil is coupled to the compressor and the refrigerant flows from the second coil to the compressor.

Abstract: A metering device may automatically control fluid flow through a valve. A control system may alter the automatic control of a metering device. In some implementations, a predetermined event may occur to alter the automatic control of the metering device.

Abstract: A system comprising a compressor, a first valve coupled to the compressor and to a first coil, a first expansion valve coupled to the first coil, and a second expansion valve. The second expansion valve coupled to a second coil. A second valve is coupled to the second coil and the compressor. A third valve is coupled to the compressor and a third coil. In response to receiving a heating demand that is below a threshold heating demand, a controller induces an artificial heating demand.

Abstract: An HVAC system includes an outdoor heat exchanger. A first indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a first zone. A second indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a second zone. A compressor is fluidly coupled to the outdoor heat exchanger, the first indoor heat exchanger, and the second indoor heat exchanger. A first circulation fan is positioned to circulate air around the first indoor heat exchanger and a second circulation fan is positioned to circulate air around the second indoor heat exchanger. A first zone controller is electrically coupled to the first indoor heat exchanger.

Abstract: An apparatus includes first and second microchannel heat exchangers and first and second pipes. The first heat exchanger includes a first inlet, a second inlet, a first tube, a second tube, a first outlet, and a second outlet. Refrigerant at the first inlet is directed through the first tube to the first outlet and the first pipe. Refrigerant at the second inlet is directed through the second tube to the second outlet and the second pipe. The second heat exchanger includes a third inlet, a fourth inlet, a third tube, a fourth tube, a third outlet, and a fourth outlet. The third inlet directs refrigerant from the first pipe through the third tube towards the third outlet. The fourth inlet directs the refrigerant from the second pipe through the fourth tube towards the fourth outlet. The first pipe overlaps the second pipe between the two heat exchangers.

Abstract: An HVAC system includes an outdoor heat exchanger. A first indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a first zone. A second indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a second zone. A compressor is fluidly coupled to the outdoor heat exchanger, the first indoor heat exchanger, and the second indoor heat exchanger. A first zone controller is electrically coupled to the first indoor heat exchanger. The first zone controller is configured to measure a temperature in the first zone, compare the measured temperature to a setpoint temperature of the first zone, and responsive to a difference between the measured temperature and the setpoint temperature, adjust a speed of a first circulation fan independent of the speed of a second circulation fan.

Abstract: An apparatus includes first and second microchannel heat exchangers and first and second pipes. The first heat exchanger includes a first inlet, a second inlet, a first tube, a second tube, a first outlet, and a second outlet. Refrigerant at the first inlet is directed through the first tube to the first outlet and the first pipe. Refrigerant at the second inlet is directed through the second tube to the second outlet and the second pipe. The second heat exchanger includes a third inlet, a fourth inlet, a third tube, a fourth tube, a third outlet, and a fourth outlet. The third inlet directs refrigerant from the first pipe through the third tube towards the third outlet. The fourth inlet directs the refrigerant from the second pipe through the fourth tube towards the fourth outlet. The first pipe overlaps the second pipe between the two heat exchangers.

Abstract: An apparatus includes a compressor, a first heat exchanger, a reheater, a first valve, a second heat exchanger, a four-way valve, a cap tube, and a blower. The compressor compresses a refrigerant. The blower moves air proximate the second heat exchanger to the reheater. During a heating mode of operation, the four-way valve is configured to direct refrigerant from the compressor to the second heat exchanger; the second heat exchanger is configured to use the refrigerant from the compressor to heat air proximate the second heat exchanger; and the cap tube is configured to allow refrigerant to bypass the reheater.

Abstract: An apparatus includes a compressor, a first heat exchanger, a reheater, a first valve, a second heat exchanger, and a blower. The compressor compresses a refrigerant. The blower moves air proximate the second heat exchanger to the reheater. During a first mode of operation: the first heat exchanger removes heat from a first portion of the refrigerant from the compressor, the first valve opens such that a second portion of the refrigerant from the compressor flows to the reheater, the second heat exchanger uses the first portion of the refrigerant from the first heat exchanger and the second portion of the refrigerant from the reheater to cool air proximate the second heat exchanger, and the reheater uses the second portion of the refrigerant from the compressor to heat the air moved by the blower.

Abstract: A system comprising a compressor, a first valve coupled to the compressor and coupled to a first coil, a first expansion valve coupled to the first coil, a second coil, and a second expansion valve. The second expansion valve coupled to a third coil, a second valve coupled to the compressor and the third coil. A controller operable to operate the first valve, the first expansion valve, the second expansion valve, and the second valve. The second coil is coupled to the compressor and the refrigerant flows from the second coil to the compressor.

Abstract: A system comprising a compressor, a first valve coupled to the compressor and coupled to a first coil, a first expansion valve coupled to the first coil, a second coil, and a second expansion valve. The second expansion valve coupled to a third coil, a second valve coupled to the compressor and the third coil. A controller operable to operate the first valve, the first expansion valve, the second expansion valve, and the second valve. The second coil is coupled to the compressor and the refrigerant flows from the second coil to the compressor.

Abstract: An HVAC system includes an outdoor heat exchanger. A first indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a first zone. A second indoor heat exchanger is fluidly coupled to the outdoor heat exchanger and disposed in a second zone. A compressor is fluidly coupled to the outdoor heat exchanger, the first indoor heat exchanger, and the second indoor heat exchanger. A first circulation fan is positioned to circulate air around the first indoor heat exchanger and a second circulation fan is positioned to circulate air around the second indoor heat exchanger. A first zone controller is electrically coupled to the first indoor heat exchanger.

Abstract: A system comprising a compressor, a first valve coupled to the compressor and to a first coil, a first expansion valve coupled to the first coil, and a second expansion valve. The second expansion valve coupled to a second coil. A second valve is coupled to the second coil and the compressor. A third valve is coupled to the compressor and a third coil. In response to receiving a heating demand that is below a threshold heating demand, a controller induces an artificial heating demand.

Abstract: An apparatus includes a compressor, a first heat exchanger, a reheater, a first valve, a second heat exchanger, and a blower. The compressor compresses a refrigerant. The blower moves air proximate the second heat exchanger to the reheater. During a first mode of operation: the first heat exchanger removes heat from a first portion of the refrigerant from the compressor, the first valve opens such that a second portion of the refrigerant from the compressor flows to the reheater, the second heat exchanger uses the first portion of the refrigerant from the first heat exchanger and the second portion of the refrigerant from the reheater to cool air proximate the second heat exchanger, and the reheater uses the second portion of the refrigerant from the compressor to heat the air moved by the blower.

Abstract: An apparatus includes first and second microchannel heat exchangers and first and second pipes. The first heat exchanger includes a first inlet, a second inlet, a first tube, a second tube, a first outlet, and a second outlet. Refrigerant at the first inlet is directed through the first tube to the first outlet and the first pipe. Refrigerant at the second inlet is directed through the second tube to the second outlet and the second pipe. The second heat exchanger includes a third inlet, a fourth inlet, a third tube, a fourth tube, a third outlet, and a fourth outlet. The third inlet directs refrigerant from the first pipe through the third tube towards the third outlet. The fourth inlet directs the refrigerant from the second pipe through the fourth tube towards the fourth outlet. The first pipe overlaps the second pipe between the two heat exchangers.

Abstract: A temperature control system that includes a sensor, a variable speed blower, and a controller. The controller is configured to receive an air temperature measurement from the sensor and determine a temperature value based on the received air temperature measurement. The controller is further configured to compare the determined temperature value to a first threshold value and a second threshold value and to operate the variable speed blower based on the comparison. The controller is configured to set the variable speed blower to a first fan speed when the temperature value is below the first threshold value and to a second fan speed when the temperature value is above the second threshold value. The controller is further configured to set the variable speed blower to a third fan speed that linearly correlates with temperature when the temperature value is between the first threshold and the second threshold.