A heat pump water heater and a method for servicing the heat pump water heater are provided. The heat pump water heater includes an evaporator, a condensate collection tray, and a condensate pump for discharging collected condensate. Notably, the operating time of the condensate pump correlates to the amount of wet operation of heat pump water heater, and increased wet operation may correlate to corrosion and wear on the heat pump water heater. Therefore, an exemplary method contemplates determining an operating time of the condensate pump and, based on the operating time, determining and communicating a recommended service schedule. In addition, an operating parameter of the heat pump water heater may be adjusted, such as switching to electric heating when the operating time exceeds a predetermined threshold.

A water mixing system attached to an existing plumbing system supplying ambient temperature water and providing temperature regulated water to a user. The water mixing system includes an insulated water tank, a heat pump connected to the insulated water tank with a heat rejecting radiator inside the insulated water tank and a heat absorbing radiator outside the insulated water tank, a temperature detector in the insulated water tank, and one outlet of the insulated water tank connected to a first inlet of a first dispensing water tank. Having a second inlet to receive the ambient temperature water from the existing plumbing system and at least one dispensing outlet, the first dispensing water tank provides mixed water of a desirable temperature from heated water from the insulated water tank and the ambient temperature water via control of the valves attached to the first inlet and the second inlet.

A heat pump heating and hot-water system includes a water heating heat exchanger for heating water by heat exchange with a heating medium heated by a heat pump unit, an indoor heating unit, a heating circulation circuit for selectively pumping the heating medium to either of the water heating heat exchanger and the indoor heating unit using a heating medium pump, and a hot-water accumulating circuit that sends water in a hot-water storage tank to the water heating heat exchanger and returns water having passed through the water heating heat exchanger to the hot-water storage tank using a water pump. The volumetric flow rate of the heating medium pumped to the water heating heat exchanger by the heating medium pump is higher than or equal to the volumetric flow rate of the water pumped to the water heating heat exchanger by the water pump.

Disclosed are a method and a system for controlling frequency of a variable-frequency compressor in a heat pump water heater. The method includes: detecting water temperature of water flowing out from a heat exchanger and water tank temperature of a water tank; determining preset water temperature of the water flowing out from the heat exchanger according to the water tank temperature; and controlling the frequency of the variable-frequency compressor according to the water temperature and the preset water temperature. The present method and system propose a control mode of frequency of the compressor based on the water temperature of the water flowing out from the heat exchanger.

A system for conditioning air circulated from an interior of a building includes a refrigerant path, an air-cooled condenser in the refrigerant path, a water-cooled condenser in the refrigerant path that transfers heat from refrigerant in the refrigerant path to the building water, an evaporator in the refrigerant path, and a control system. The control system moves the system between operation of the air-cooled condenser and the water-cooled condenser based upon predetermined system conditions.

A hot water unit fluid supply control system for a hot water unit is disclosed. The hot water unit has a heating system that is operable in a heating cycle to heat up water in at least a first region of the water unit, and a sensor arrangement for sensing a temperature of water of the hot water unit. The control system comprises a control unit configured to: receive operational data relating to an operation of the heating system; receive temperature data from the sensor arrangement; and allow for a volume of water from the first region to be released from the hot water unit as treated water or usable water based on: the operational data, and the temperature data from the sensor arrangement.

A hot water unit fluid supply control system for a hot water unit is disclosed. The hot water unit has a heating system that is operable in a heating cycle to heat up water in at least a first region of the water unit, and a sensor arrangement for sensing a temperature of water of the hot water unit. The control system comprises a control unit configured to: receive operational data relating to an operation of the heating system; receive temperature data from the sensor arrangement; and allow for a volume of water from the first region to be released from the hot water unit as treated water or usable water based on: the operational data, and the temperature data from the sensor arrangement.

An air conditioning system includes a heat pump unit including a radiator usable with a refrigerant, a gas furnace unit including a heating section arranged to heat passing air, a blower arranged to generate an air flow that passes through the radiator and the heating section, and a controller configured to control each action of the heat pump unit, the gas furnace unit, and the blower. The controller operates either the heat pump unit or the gas furnace unit as a heat source unit, generates a capacity command used to variably adjust operating capacity of the heat source unit, and executes switch control in order to switch the heat source unit from either one of the heat pump unit or the gas furnace unit to the other when an operating capacity level designated in the capacity command is within a predetermined numerical range for a predetermined time.

An air conditioning system includes a heat pump section performing indoor air-warming by using a vapor-compression refrigeration cycle, a separate heat source section performing indoor air-warming by using a heat source separate from the heat pump section, and a control unit configured to control actions of the heat pump section and the separate heat source section. When a heat pump air-warming operation is being performed, and when a first switching condition is met, the control unit switches from the heat pump air-warming operation to a separate heat source air-warming operation. The first switching condition is that an outside air temperature reaches a first switching outside air temperature and an air-warming capability of the heat pump section reaches an upper limit.

The hot and cold water air conditioning system includes a water temperature sensor configured to detect a temperature of water flowing out of the heat pump heat source apparatus by an operation of the water circulation pump, and a controller configured to perform, in a heating operation, on/off normal control that turns on a compressor when the water temperature detected by the water temperature sensor becomes lower than a target water temperature and turns off the compressor when the water temperature becomes higher than a first temperature value higher than the target water temperature, and to switch from the on/off normal control, upon repeating the on/off operation of the compressor at a minimum frequency necessary for an operation of the compressor in the on/off normal control, to on/off restriction control that turns on the compressor when the water temperature becomes lower than a second temperature value lower than the target water temperature and turns off the compressor when the water temperature becomes equal to or higher than a third temperature value higher than the target water temperature.