A micro environmental control system that can remove or add 30W from or to the near range personal microenvironment of a user. For cooling, the X uses a micro vapor compression system during the un-occupied period to freeze a phase-change-material in a thermal storage module. A fan then moves air over the phase-change-material to deliver cooled air. Heating is delivered by a small electric heater integrated into a condensing unit. The resulting system is inexpensive to build and uses a limited amount of energy.

The present disclosure discloses a control method for a multi-split air conditioning system and a multi-split air-conditioning system, the multi-split air conditioning system, including a compressor and a plurality of indoor units respectively arranged on a plurality of parallel branches, the indoor unit including a fan and the control method including: in a cooling mode, when the multi-split air conditioning system needs oil return, the multi-split air conditioning system opening a branch where an indoor unit in an off state is located, determining whether the indoor unit has reached a dewing condition, opening the branch on which the indoor unit is located, and controlling the fan of the indoor unit according to a determination result.

Described is a vector control system for a vapor compression circuit. The vector control system may monitor the vapor compression circuit and adjust the speed of one or more motors to increase efficiency by taking into account the torque forces placed on a compressor motor.

In one embodiment, an HVAC system includes an indoor unit having a furnace, an outdoor heat pump unit having a compressor and an outdoor coil, a refrigerant line coupled to the indoor unit and the outdoor heat pump unit, and an EEV coupled to the refrigerant line. The HVAC system further includes one or more controllers operable to determine an occurrence of a first event, initiate a closure of the EEV, initiate operation of the compressor at a completion of the air conditioning cycle to pump down a refrigerant to the outdoor coil, and cease operation of the compressor when a low-pressure switch is tripped.

An HVAC system includes a pressure sensor is disposed in a suction line between a compressor and an indoor heat-exchange coil. The pressure sensor is electrically coupled to a compressor controller. An HVAC controller is electrically coupled to the compressor controller. The HVAC controller is configured to transmit a signal to the compressor controller to activate and de-activate the compressor. The compressor controller is configured to receive a signal from the HVAC controller to activate the compressor, determine a start speed of the compressor, monitor a run time of the compressor, and modulate a speed of the compressor.

Provided is an air conditioning apparatus capable of sufficiently raising the temperature of hot air to be blown out when receiving a request for high-temperature air temporarily raising the temperature of the hot air. A first use side unit includes a first use side heat exchanger and a first use side fan. A second use side unit includes a second use side heat exchanger and a second use side fan. When the first use side unit receives a request for the high-temperature air and the second use side unit receives no request for the high-temperature air, the air conditioning apparatus shifts to a mode that performs control so as to reduce the airflow volume of the second use side fan or make the airflow volume of the second use side fan zero such as reducing the number of revolutions of the second use side fan in another room by 40 rpm in step (S7).

A vector control system is used to control a vapor compression circuit that includes a compressor motor. The vector control system is used to monitor the vapor compression circuit and adjust the speed of one or more motors within the vapor compression circuit to increase efficiency of the system by taking into account the torque forces placed on the compressor motor.

A method for controlling a heat pump is provided. A working mode of the heat pump is determined. Based on a determination that the working mode of the heat pump is a heating mode, an ambient temperature of the heat pump is determined. Based on a determination that the ambient temperature of the heat pump is higher than a first predetermined temperature, a first compressor of the heat pump is operated. Based on a determination that the ambient temperature of the heat pump is lower than the first predetermined temperature, both the first compressor and a second compressor of the heat pump are enabled to operate, in response to a two-stage thermostat. The first compressor and the second compressor are coupled in parallel. The method allows the heat pump to be suitable for a cold climate.

A system includes a condensing unit, a valve, and a unit cooler. The condensing unit is configured to condense refrigerant. The valve is configured to control the flow of the refrigerant from the condensing unit to the unit cooler. The unit cooler is configured to operate in a refrigeration mode and a stir-cycle mode. The unit cooler is configured to operate at a first speed during the refrigeration mode and at a second speed for a first period of time and at a third speed for a second period of time during the stir-cycle mode. The second speed is slower than the first speed and the third speed is slower than the second speed. Electric power is supplied to the unit cooler throughout the refrigeration mode and the stir-cycle mode.

An air conditioning system includes a bypass passage and a cooling-heating switching mechanism. The bypass passage is configured to be at least a part of a flow passage connecting a third port to a refrigerant inlet of a compressor. A linear expansion valve opens and closes the bypass passage. The cooling-heating switching mechanism includes check valves and four-way valves. The four-way valve causes a refrigerant outlet of the check valve to communicate with one of the refrigerant inlet and a refrigerant outlet of the compressor. The four-way valve causes a refrigerant inlet of the check valve to communicate with one of the refrigerant inlet and the refrigerant outlet of the compressor and causes a port to communicate with the other of the refrigerant inlet and the refrigerant outlet.