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.

An outdoor unit includes a heat exchanger, a fan having a motor having coils to blow air to the heat exchanger, a connection switching unit to switch a connection state of the coils between a first connection state and a second connection state in which a line voltage is lower than a line voltage in the first connection state, and a temperature sensor to detect a temperature. When the motor is not driven, the connection switching unit sets the connection state of the coils to the second connection state. When the motor rotates, the connection switching unit sets the connection state of the coils to the first connection state if a detected temperature by the temperature sensor is higher than or equal to a threshold, and the connection switching unit sets the connection state of the coils to the second connection state if the detected temperature is lower than the threshold.

A method for controlling an air conditioner includes, after the air conditioner is turned on, controlling an indoor ambient temperature sensor, an indoor heat exchanger temperature sensor, an outdoor heat exchanger temperature sensor, an outdoor ambient temperature sensor, and an exhaust gas temperature sensor to determine an indoor ambient temperature, an indoor heat exchanger temperature, an outdoor heat exchanger temperature, an outdoor ambient temperature, and an exhaust gas temperature, respectively, determining a first, second, third, fourth, and fifth compressor frequencies based on the indoor ambient temperature, the indoor heat exchanger temperature, the outdoor heat exchanger temperature, the outdoor ambient temperature, and the exhaust gas temperature, respectively, determining a minimum compressor frequency based on the first, second, third, fourth, and fifth compressor frequencies, and controlling a compressor of the air conditioner to operate at the minimum compressor frequency.

A method for controlling an air conditioner includes, after the air conditioner is turned on, controlling an indoor ambient temperature sensor, an indoor heat exchanger temperature sensor, an outdoor heat exchanger temperature sensor, an outdoor ambient temperature sensor, and an exhaust gas temperature sensor to determine an indoor ambient temperature, an indoor heat exchanger temperature, an outdoor heat exchanger temperature, an outdoor ambient temperature, and an exhaust gas temperature, respectively, determining a first, second, third, fourth, and fifth compressor frequencies based on the indoor ambient temperature, the indoor heat exchanger temperature, the outdoor heat exchanger temperature, the outdoor ambient temperature, and the exhaust gas temperature, respectively, determining a minimum compressor frequency based on the first, second, third, fourth, and fifth compressor frequencies, and controlling a compressor of the air conditioner to operate at the minimum compressor frequency.

An environmental control system comprises a fluid flow path which has a pump and circulates liquid to a first heat exchanger in a first room and to a second heat exchanger in a second room. The fluid flow path comprises a pump. A user inputs a target temperature for the first room via a first user interface that is located in the first room, which is communicated to the control unit and a sensor located in the room communicates the temperature in the first room to the control unit. A user inputs a target temperature for the second room via a second user interface that is located in the second room, which is communicated to the control unit and a sensor located in the room communicates the temperature in the second room to the control unit. The control is physically isolated from the user interfaces and temperatures sensors.

An environmental control system comprises a fluid flow path which has a pump and circulates liquid to a first heat exchanger in a first room and to a second heat exchanger in a second room. The fluid flow path comprises a pump. A user inputs a target temperature for the first room via a first user interface that is located in the first room, which is communicated to the control unit and a sensor located in the room communicates the temperature in the first room to the control unit. A user inputs a target temperature for the second room via a second user interface that is located in the second room, which is communicated to the control unit and a sensor located in the room communicates the temperature in the second room to the control unit. The control is physically isolated from the user interfaces and temperatures sensors.

A single unit HVAC system for a unit in a multi-unit building comprises a first heat exchanger thermally connected to a riser stack, a plurality of fan coils, each fan coil comprising a unit heat exchanger and a motor and fan assembly wherein, in operation, the motor and fan assembly delivers air to a location in the unit, and a closed loop fluid flow path extending between the first heat exchanger and the plurality of unit heat exchangers. In operation, the first heat exchanger exchanges heat between the riser stack fluid and the closed loop fluid, each unit heat exchanger exchanges heat between the closed loop fluid and air that is delivered to a different room in the unit.

A single unit HVAC system for a unit in a multi-unit building comprises a first heat exchanger thermally connected to a riser stack, a plurality of fan coils, each fan coil comprising a unit heat exchanger and a motor and fan assembly wherein, in operation, the motor and fan assembly delivers air to a location in the unit, and a closed loop fluid flow path extending between the first heat exchanger and the plurality of unit heat exchangers. In operation, the first heat exchanger exchanges heat between the riser stack fluid and the closed loop fluid, each unit heat exchanger exchanges heat between the closed loop fluid and air that is delivered to a different room in the unit.

The present disclosure provides materials and methods related to passive cooling systems. In particular, the present disclosure provides a condensorator heat exchanger with a single microchannel coil that integrates the evaporator and condenser into one assembly. The passive heat exchanger systems of the present disclosure provide enhanced cooling capacity and airflow in environments ranging from outdoor electronic enclosures to commercial and residential buildings.

The present disclosure provides materials and methods related to passive cooling systems. In particular, the present disclosure provides a condensorator heat exchanger with a single microchannel coil that integrates the evaporator and condenser into one assembly. The passive heat exchanger systems of the present disclosure provide enhanced cooling capacity and airflow in environments ranging from outdoor electronic enclosures to commercial and residential buildings.