What is an evaporator coil?

An evaporator coil, also known as an evaporator core or cooling coil, is a key component of an air conditioning or refrigeration system. It is located on the indoor unit of the system and works to absorb heat from the surrounding air or liquid.

The evaporator coil consists of a network of small tubes or pipes that are often made of copper or aluminum. These tubes are typically arranged in a serpentine pattern to maximize surface area. Fins or plates are attached to the tubes to further increase the surface area available for heat transfer.

When the air conditioner or refrigeration system operates, a refrigerant (such as R-410A or R-22) flows through the evaporator coil. The refrigerant, in its liquid state, enters the coil at a low pressure and temperature. As the warm air from the surroundings passes over the coil, the refrigerant absorbs the heat from the air, causing the refrigerant to evaporate and change into a gas.

During this process, the heat energy is transferred from the air to the refrigerant, which cools down the air. The cooled air is then circulated back into the space, providing a cooling effect. The now-gaseous refrigerant then travels to the compressor where it is pressurized and sent to the condenser coil to release the absorbed heat.