Abstract: A heating, ventilation, air conditioning or refrigeration system includes a refrigerant circuit having a compressor, a first condenser, and a second condenser arranged in parallel or in series with the first condenser. A first expansion valve is in fluid communication with the first condenser to selectably direct a refrigerant flow through the first condenser, and a second expansion valve is in fluid communication with the second condenser to selectably direct the refrigerant flow through the second compressor. An evaporator is configured to remove thermal energy from a fluid flow through the evaporator via the refrigerant flow through the evaporator. A fluid flow circuit includes a liquid cooler in selectable fluid communication with the second condenser and/or the evaporator and the evaporator, through which the fluid flow is directed for thermal energy exchange with the refrigerant flow.

Abstract: A heat pump system includes a refrigerant circuit, at least one compressor, an evaporator, and a controller programmed to defrost the evaporator in a defrost mode, wherein in the defrost mode the controller is programmed to monitor the evaporator to detect frost creation thereon, and reduce the speed of the at least one compressor and/or reduce the number of some, but not all operating compressors of the at least one compressor, if frost creation is detected on the evaporator. In some embodiments, the controller is programmed to defrost the evaporator in a second defrost mode. In the second defrost mode the controller is programmed to monitor the evaporator to detect frost creation thereon, turn off the at least one compressor when frost is detected on the evaporator, and operate a fan to force ambient air over the evaporator to defrost the evaporator.

Abstract: A heating, ventilation, air conditioning or refrigeration system includes a refrigerant circuit having a compressor, a first condenser, and a second condenser arranged in parallel or in series with the first condenser. A first expansion valve is in fluid communication with the first condenser to selectably direct a refrigerant flow through the first condenser, and a second expansion valve is in fluid communication with the second condenser to selectably direct the refrigerant flow through the second compressor. An evaporator is configured to remove thermal energy from a fluid flow through the evaporator via the refrigerant flow through the evaporator. A fluid flow circuit includes a liquid cooler in selectable fluid communication with the second condenser and/or the evaporator and the evaporator, through which the fluid flow is directed for thermal energy exchange with the refrigerant flow.

Abstract: A heat pump system includes a refrigerant circuit, at least one compressor, an evaporator, and a controller programmed to defrost the evaporator in a defrost mode, wherein in the defrost mode the controller is programmed to monitor the evaporator to detect frost creation thereon, and reduce the speed of the at least one compressor and/or reduce the number of some, but not all operating compressors of the at least one compressor, if frost creation is detected on the evaporator. In some embodiments, the controller is programmed to defrost the evaporator in a second defrost mode. In the second defrost mode the controller is programmed to monitor the evaporator to detect frost creation thereon, turn off the at least one compressor when frost is detected on the evaporator, and operate a fan to force ambient air over the evaporator to defrost the evaporator.