Understanding A/C: What’s the Difference Between Evaporator and Condenser Coils?

  • Plumbing Preventative Maintenance

  • To most folks, the science behind air conditioning is pure magic. The process cools your house and that’s all you care about… until it stops working. However, a basic understanding of the process behind air conditioning will provide you with a better ability to troubleshoot problems. Evaporator and condenser coils are at the heart of this process.

    coils

    Source: Freedigitalphotos

    Why Refrigerant Is So Important

    First, it’s important to understand how refrigerant plays a role in air conditioning. It easily transitions between liquid and gas, and when it does, it either extracts heat from the air or releases heat into the air. Pressure aids the process.

    How an Air Conditioner Works

    In a split-system central air conditioner, liquid refrigerant, also called coolant, is pumped into the home. It flows through an evaporator coil, which is either located in a dedicated air handling unit or attached to the furnace plenum.

    Before the coolant flows into the evaporator coil, an expansion valve reduces pressure on the refrigerant, causing it to evaporate into a gas. As this happens, the refrigerant extracts heat energy from the surrounding air. The removal of heat from the air cools it off, and that cooled air is blown away from the coil and circulated throughout the home via a blower fan and air ducts.

    At this point, the A/C pumps the gaseous refrigerant back outside to the condenser/compressor unit, usually located on a concrete pad next to the house. The compressor squeezes the gas, turning it back into a liquid. As the gas returns to a liquid state , heat is released into the outside air, blown away by an exhaust fan.

    All air conditioning systems — central, portable and package units — operate on the same principle. Electric, air-source heat pumps cool homes in this manner as well, using a reversing valve to switches the process from indoor cooling to heating. When this happens, the indoor evaporator coil operates as a condensing coil during heating, and the outdoor condenser coil becomes an evaporator coil.

    For more information on how evaporator and condenser coils cool your greater Cincinnati home, please contact us at Apollo Heating, Cooling and Plumbing.