heat pump 
Device exchanging heat between two environments of different temperatures; it can either heat or cool a house, depending on how the circuit is set.
Device compressing the refrigerant to the desired pressure.
Propeller-shaped blades drawing in outdoor air (heating mode) or expelling indoor air (cooling mode).
Mechanism automatically cutting off the power supply in the event of overload.
Part of the pump in which, depending on the setting, the outside air is tapped (heating mode) or the indoor air is cooled (cooling mode).
Conduit connecting the heat pump to the dwelling’s electric system.
Conduit circulating a refrigerant, thus enabling the heat transfer.
Duct carrying forced hot air (heating mode) or cool air (cooling mode) into the house.
Part of the pump that, depending on the setting, either transfers outdoor heat into the house (heating mode) or transfers heat from the indoors to the outdoors (cooling mode).