What happens to the refrigerant after it passes through the evaporator coil?

After the refrigerant passes through the evaporator coil, it undergoes a phase change from liquid to gas, which is the primary function of the evaporator in a heat pump system. During this process, the refrigerant absorbs heat from its surroundings, which is typically the indoor air. This absorption of heat lowers the temperature of the air and provides effective cooling for the space being conditioned.

This process is crucial because it allows the heat pump to extract heat from the indoor environment, even when heating in colder climates, thereby improving energy efficiency. The refrigerant's phase change and heat absorption enable the system to efficiently transfer thermal energy and contribute to the heating or cooling of residential spaces.