Heat pump system (100) comprising at least one heat medium circuit (210,220,230,240,250,310,320,410,420,430,440,450,460) in turn comprising a compressor (211), an expansion valve (232,242), at least two different primary heat sources or sinks selected from outdoor air, a water body, the ground or exhaust air, at least one of two different secondary heat sources or sinks selected from indoors air, pool water and tap water, a respective temperature sensor (412,432) at each of said primary heat sources or sinks, a valve means (421,431,451) for selectively directing the primary-side heat medium to at least one of said primary heat exchanging means, and a control means (500). The invention is characterised in that, in a secondary-side heating operating mode, the temperature of said primary heat sources or sinks is measured, and in that the primary-side heat medium is directed only to available primary heat exchanging means associated with the heat sources or sinks with the highest temperature. The invention also relates to a method.

An air conditioning system according to an embodiment may include an outdoor unit including a compressor; at least one distributor connected to the outdoor unit and including a condenser and an evaporator that exchange heat between a refrigerant and water with each other; a plurality of heating pipes in communication with the condenser; a plurality of cooling pipes in communication with the evaporator; a plurality of fan coil units connected to the heating pipes or the cooling pipes; and a controller configured to perform a heating pipe search operation for matching a portion of the plurality of fan coil units with the plurality of heating pipes, and a cooling pipe search operation for matching another portion of the plurality of fan coil units with the plurality of cooling pipes, in parallel.

A refrigeration system includes a free cooling system having an air-cooled heat exchanger, where the air-cooled heat exchanger includes a fan configured to move air over coils of the air-cooled heat exchanger to remove heat from a coolant flowing through the air-cooled heat exchanger, and a mechanical cooling system with a refrigerant loop that includes an evaporator, a compressor, and a condenser disposed along the refrigerant loop, where the compressor is configured to circulate a refrigerant through the refrigerant loop, and wherein the evaporator is configured to receive the coolant and transfer heat from the coolant to the refrigerant. The refrigeration system also includes a controller configured to adjust a fan speed of the fan up to a threshold fan speed, to initiate operation of the compressor when the fan speed reaches the threshold fan speed, wherein the fan speed and a compressor speed of the compressor are based at least on an ambient air temperature and a cooling load demand.

A method for controlling a fan (6) of a vapour compression system (1) is disclosed, the fan (6) being arranged to provide a secondary fluid flow across a heat rejecting heat exchanger (3). A temperature difference, T=T.sub.outT.sub.amb, between a temperature, T.sub.out, of refrigerant leaving the heat rejecting heat exchanger (3) and a temperature, T.sub.amb, of ambient air of the heat rejecting heat exchanger (3) is established. A setpoint value, T.sub.setp, for the temperature difference, T, is obtained, the setpoint value, T.sub.setp, being dependent on the fan speed of the fan (6) in such a manner that the setpoint value, T.sub.setp, increases as the fan speed increases. The fan speed of the fan (6) is controlled in order to control the temperature difference, T, in accordance with the obtained setpoint value, T.sub.setp.

Devices, systems, and methods are disclosed for cooling using both air and/or liquid cooling sub circuits. A vapor compression cooling system having both an air and liquid cooling sub circuit designed to service high sensible process heat loads that cannot be solely cooled by either liquid or air is provided.

Devices, systems, and methods are disclosed for cooling using both air and/or liquid cooling sub circuits. A vapor compression cooling system having both an air and liquid cooling sub circuit designed to service high sensible process heat loads that cannot be solely cooled by either liquid or air is provided.

An air-conditioning apparatus according to the present invention includes: a heat-source-side unit including a heat-source-side heat exchanger and a compressor; a plurality of load-side units including respective load-side heat exchangers and respective load-side expansion devices; and a relay unit connected between the heat-source-side unit and the plurality of load-side units by a first gas pipe and a first liquid pipe. The relay unit includes a gas/liquid separator which separates refrigerant supplied from the heat-source-side unit into gas refrigerant and liquid refrigerant, a gas-refrigerant supply pipe and a liquid-refrigerant supply pipe which are connected to the gas/liquid separator and each of the plurality of load-side units, a drain pan which is provided in a housing of the relay unit and which receives dew-condensation water, and a heat transfer body which is provided in the drain pan and which is in contact with the liquid-refrigerant supply pipe.

A method of initiating a low-energy cooling mode using a controller of an HVAC system includes measuring a temperature of ambient air proximal to a condenser coil and determining whether the temperature of the ambient air proximal the condenser coil is less than a temperature threshold. If the temperature of the ambient air is less than the temperature threshold, the HVAC system is configured to operate in a low-energy cooling mode. In the low-energy cooling mode, the controller opens a first bypass valve to allow a refrigerant to bypass a compressor and the compressor is powered off. The HVAC system is operated until a cooling demand has been met.

In an operation mode in which an indoor heat exchanger is used as a condenser, a refrigeration cycle apparatus changes to an operation state in which a water heat exchanger provided to a hot water storage tank is used as an evaporator and refrigerant flowing through the water heat exchanger is evaporated by heat generated by a heat source such as an electric heater, under a low outdoor air temperature condition.

A method for controlling a supply of refrigerant to an evaporator of a vapour compression system, such as a refrigeration system, an air condition system or a heat pump. During normal operation, the opening degree of the expansion valve is controlled on the basis of an air temperature, T.sub.air, of air flowing across the evaporator and/or on the basis of superheat of refrigerant leaving the evaporator. If at least one sensor used for obtaining T.sub.air or the superheat is malfunctioning, operation of the vapour compression system is switched to a contingency mode. A reference temperature, T.sub.out, ref, is calculated, based on previously obtained values of a temperature, T.sub.out, of refrigerant leaving the evaporator, during a predefined previous time interval, and subsequently the opening degree of the expansion valve is controlled on the basis of the obtained temperature, T.sub.out, in order to reach the calculated reference temperature, T.sub.out, ref.