Final answer:
The evaporator in a heat pump refrigeration cycle absorbs external heat, facilitating heat transfer to the indoor space. The coolant's phase change from liquid to gas, and subsequent increased pressure and temperature by the compressor, culminates in heat release inside via the condenser. The process's efficiency is quantified using a coefficient of performance.
Step-by-step explanation:
At temperatures above 45 degrees F, the heat pump refrigeration cycle allows the evaporator to absorb heat from the outside air. As a critical component of the heat pump system, the evaporator's role is to facilitate heat transfer. During milder temperatures, the air outside contains sufficient thermal energy that the evaporator can extract, even though it is colder than the indoor environment.
The process involves the refrigerant in the heat pump system. It absorbs heat from the environment and vaporizes within the evaporator coils. This gaseous refrigerant then travels to the compressor where its pressure and temperature are increased. The high-temperature gas is finally conveyed to the condenser within the heated space where it releases its heat as it condenses. These transferred energy changes during phase transitions can be represented on a heating or cooling curve.
Therefore, the heat pump functions by moving heat energy from the outdoor environment into the indoor space to provide warmth. The efficiency of this process is often represented by a coefficient of performance which measures the amount of heating or cooling provided divided by the electrical energy input required for the compressor.