Abstract: There is provided a heat pump installation for the heating of tap water and for room heating purposes e.g., associated office spaces in large warehouses where a number of refrigerators are operating. The heat pump receives its input heat from the heat liberated by the refrigerators.

Abstract: Waste heat from paper mills, for example, is used partly as energy input to a heat motor, partly as energy input to a heat pump. The heat motor drives the compressor of the heat pump which means that no external high grade energy has to be supplied to drive the heat pump. The heat leaving the hot side of the heat pump can be utilized readily, directly or after heating of feed water, for example, possibly for vaporization thereof, for example, in the process that left the waste heat.

Abstract: There is provided a method and an apparatus for controlling the temperature of a plurality of rooms having mutually different and varying heat requirements, among which rooms at least one normally has a cooling requirement.The common input air flow to the rooms passes a heat exchanger and is cooled to the requisite temperature for the room having a cooling requirement, while the separate input air flows to the respective rooms are afterheated by means of after heating banks, one for each room, to the desired temperature. The heat exchanger is, or is connected to, an evaporator in a refrigerator (heat pump) the condenser of which is located in the common output airflow from the rooms. The heating banks are heat supplied by part of the condensation heat of the refrigerant vapor.

Abstract: In an apparatus for defrosting an evaporator in a heat pump which is driven by a compressor, the evaporator consists of a fan and a heat exchanger through which the fan drives air for heat exchange with the heat transport medium flowing through the heat exchanger. A pressure sensitive switch is arranged to actuate a member for reversal of the pumping direction of the compressor when the pressure differential .sigma. p of the air over the heat exchanger has reached a predetermined value, and a temperature sensitive switch which senses the temperature at the heat exchanger, is arranged to actuate the reversal member to maintain the reversed pumping direction of the compressor as long as the temperature at the heat exchanger is less than or equal to 0.degree. C.

Abstract: There is provided a method and apparatus for heating tap water and radiator water by means of a heat pump, and complementarily also by means of a conventional fuel fired furnace. The condensor unit of the heat pump is divided into two heat exchangers. The first heat exchangers takes care of the superheat, and some of the condensation heat of the coolant vapor of the heat pump, and heats the tap water to a temperature which is higher than the condensation temperature. The second heat exchanger condensor heats the radiator water to a temperature corresponding to the condensation temperature of the coolant vapor.

Abstract: There is provided a heating installation comprising a heat pump and a fuel-fired boiler to which a radiator circuit is connected. A separate hot water heater may be coupled in parallel with the boiler. The hot side of the heat pump is connected to a first shunt pipe in the radiator circuit and is thus coupled in parallel with the boiler. A second shunt pipe is coupled in parallel with the boiler and a third shunt pipe is connected between the hot side of the first shunt pipe and the second shunt pipe. A first threeway shunt valve is connected between the first and third shunt pipes and a second threeway shunt valve is connected between the second shunt pipe and the hot side of the radiator circuit. These two shunt valves may be interlocked.Further the compressor of the heat pump may be arranged to be controlled by the pressure of the refrigerant in the heat pump circuit between the evaporator and the compressor.

Abstract: There is provided a heat pump system comprising two cascade coupled heat pumps. The hot side of the system may be connected in series with an oil-fired boiler in a radiator circuit of conventional water heating installation, wherein a hot water heater is coupled in parallel to the boiler. The low temperature heat pump has two series connected condensors of which one is connected to the evaporator of the high temperature heat pump, while the other is useful for heating radiator water flowing in a shunt pipe parallel with the boiler. A threeway shunt valve controls the mix of water of different temperatures from the boiler and the shunt pipe respectively, so that water of a desired temperature is let into the raiser pipe of the radiator circuit.