What is the function of the evaporator coil in an HVAC system?

The function of the evaporator coil in an HVAC system is primarily to absorb heat from indoor air. When warm air from the interior space passes over the evaporator coil, which contains a refrigerant at low pressure and temperature, heat is extracted from the air. This process causes the refrigerant to evaporate as it absorbs the heat, effectively cooling the air that is then circulated back into the living space. This absorption of heat not only cools the air but also dehumidifies it, contributing to overall comfort in the environment.

In an HVAC context, this heat absorption is crucial because it is part of the refrigeration cycle, which also includes the compressor, condenser, and expansion valve. The evaporator coil is specifically designed for the initial stage of this cycle, where it transforms the refrigerant from liquid to gas by absorbing heat. This function is opposite to that of the condenser, which releases heat into the environment, thus highlighting the specific role of the evaporator coil in the overall process of heating and cooling within the system.