The heat pump consists of the condenser, expansion valve, evaporator, and compressor. The environment around the heat pump refers to the outdoor and indoor spaces where heat absorption and heat release occur during the heating mode.
In the context of a heat pump system, the heat pump itself consists of four basic components, which are the condenser (1), the expansion valve (2), the evaporator (3), and the compressor (4).
Specifically, the evaporator and the compressor are crucial components for absorbing heat from the environment and raising its temperature and pressure respectively, while the condenser is integral for transferring heat into the inside space and the expansion valve aids in the regulation of refrigerant flow back to the evaporator.
The environment around the heat pump is represented by the source of heat transfer; in the heating mode, this is the colder outdoor air from which heat is absorbed at the evaporator (3) and the indoor space into which heat is released at the condenser coils (1).