A multi-type air conditioner is provided including an outdoor unit and a plurality of indoor units connected to the outdoor unit by a liquid pipe and a gas pipe. The plurality of indoor units includes a first indoor unit including first and second heat exchangers and first and second heat exchanger connecting pipes, and a second indoor unit. An indoor heat exchanger connecting pipe connects the first and second indoor units, and a liquid pipe connecting tube connects the first indoor unit and the liquid pipe. Opening amounts of a first indoor expansion valve, and first and second bypass expansion valves provided in the first indoor unit are opened selectively to operate the first heat exchanger as a condenser and the second heat exchanger as an evaporator to continuously drive a dehumidification mode while maintaining a room temperature within a predefined range.

Detector (300) detects information regarding air quality. First communicator (330) is compatible with a first system for controlling equipment. Second communicator (340) is compatible with a second system for accumulating the information regarding the air quality. Controller (310) transmits the information regarding the air quality to the second system based on a state of the information regarding the air quality having been detected.

Detector (300) detects information regarding air quality. First communicator (330) is compatible with a first system for controlling equipment. Second communicator (340) is compatible with a second system for accumulating the information regarding the air quality. Controller (310) transmits the information regarding the air quality to the second system based on a state of the information regarding the air quality having been detected.

A residual value calculation system is for an air conditioner including an indoor unit and an outdoor unit. The residual value calculation system includes a management device that manages the air conditioner. The management device includes an obtaining unit and a calculating unit. The obtaining unit obtains first environment information related to an installation environment of the indoor unit, and second environment information related to an installation environment of the outdoor unit. The calculating unit calculates a residual value of the air conditioner after use over a set period based on the first environment information and the second environment information, the residual value including at least one of an initial estimation residual value and an actual estimation residual value based on actual use.

A residual value calculation system is for an air conditioner including an indoor unit and an outdoor unit. The residual value calculation system includes a management device that manages the air conditioner. The management device includes an obtaining unit and a calculating unit. The obtaining unit obtains first environment information related to an installation environment of the indoor unit, and second environment information related to an installation environment of the outdoor unit. The calculating unit calculates a residual value of the air conditioner after use over a set period based on the first environment information and the second environment information, the residual value including at least one of an initial estimation residual value and an actual estimation residual value based on actual use.

An actuator in a HVAC system includes a mechanical transducer, an input connection configured to receive a power supply line voltage, and a voltage divider circuit. The voltage divider circuit includes a first capacitor in series between the input connection and the mechanical transducer, a second capacitor in parallel with the first capacitor between the input connection and the mechanical transducer, and a first transistor operable to connect and disconnect the first capacitor and/or the second capacitor from the voltage divider circuit based on the power supply line voltage, thereby adjusting a capacitance between the input connection and the mechanical transducer. The voltage divider circuit is configured to receive the power supply line voltage from the input connection, use at least one of the first capacitor or the second capacitor to reduce the power supply line voltage to a reduced voltage, and provide the reduced voltage to the mechanical transducer.

An actuator in a HVAC system includes a mechanical transducer, an input connection configured to receive a power supply line voltage, and a voltage divider circuit. The voltage divider circuit includes a first capacitor in series between the input connection and the mechanical transducer, a second capacitor in parallel with the first capacitor between the input connection and the mechanical transducer, and a first transistor operable to connect and disconnect the first capacitor and/or the second capacitor from the voltage divider circuit based on the power supply line voltage, thereby adjusting a capacitance between the input connection and the mechanical transducer. The voltage divider circuit is configured to receive the power supply line voltage from the input connection, use at least one of the first capacitor or the second capacitor to reduce the power supply line voltage to a reduced voltage, and provide the reduced voltage to the mechanical transducer.

A heating and cooling system that includes a condenser coil configured to receive a refrigerant. A first compressor and a second compressor that pump the refrigerant through the condenser coil. A first condenser fan and a second condenser fan that push air over the condenser coil. A controller that receives a signal indicative of an ambient air temperature, a signal indicative of an operational status of the first compressor, and a signal indicative of an operational status of the second compressor. The controller controls operation of the first condenser fan and the second condenser fan in response to the signal indicative of the ambient air temperature, the signal indicative of the operational status of the first compressor and the signal indicative of the operational status of the second compressor.

A heating and cooling system that includes a condenser coil configured to receive a refrigerant. A first compressor and a second compressor that pump the refrigerant through the condenser coil. A first condenser fan and a second condenser fan that push air over the condenser coil. A controller that receives a signal indicative of an ambient air temperature, a signal indicative of an operational status of the first compressor, and a signal indicative of an operational status of the second compressor. The controller controls operation of the first condenser fan and the second condenser fan in response to the signal indicative of the ambient air temperature, the signal indicative of the operational status of the first compressor and the signal indicative of the operational status of the second compressor.

A thermostat is disclosed. The thermostat can include one or more temperature sensors configured to measure one or more temperature values. The thermostat can include a processing circuit. The processing circuit can receive the one or more temperature values from the one or more temperature sensors. The processing circuit can receive one or more central processing unit (CPU) usage values, wherein the one or more CPU usage values indicate computing usage of the processing circuit. The processing circuit can determine, based on an empirical model comprising one or more gain values and one or more filters and based on one or more signals, a temperature of the building. The one or more signals comprise the one or more temperature values and the one or more CPU usage values. The empirical model accounts for dynamics of heat generated by the processing circuit and airflow acting on the thermostat.