Understanding HVAC Coils and How They Work

Coils are the most important part of your HVAC (heating, ventilation and air conditioning) system. They make your home cool in the summer and warm in the winter. Understanding how your HVAC coils work and what to do to maintain them play a big role in saving you from a broken heat pump or air conditioner.

Types of HVAC Coils
There are two coils inside a central air conditioner or heat pump system that make it possible for these systems to complete the heat exchange process, which is the basis of refrigerated cooling and, in the case of heat pumps, heating. The coils form a loop and, even though they’re continuous, each has a different function.

The evaporator coil absorbs heat and moisture from the air to cool your home. It is located inside the air handler or attached as a separate piece attached to the furnace and is made up of copper, steel, or aluminum.

The condenser coil removes heat from the refrigerant and releases that heat outdoors. The condenser coil is located outside the home and is part of the air conditioner or heat pump. It is often made of copper or aluminum tubing with aluminum fins so heat can be rapidly transferred.

In a heat pump system, the evaporator and condenser coils are flipped when operating in heating mode. The indoor coil becomes the condenser and releases the heat into the airstream to warm the home.

Exclusive to Lennox, the Quantum coil is made up of an all-aluminum design with a proprietary aluminum alloy that has been tested under extreme conditions to reduce corrosion and improve durability.

How Do They Work?

These two coils work together to reach the temperature set on your thermostat. The system removes heat from the air in your home, carries the heat through the air conditioner and sends that warm air outside. To do this, refrigerant (a cooling agent) passes through the evaporator coil in the air conditioning system, carrying and releasing heat through the condenser coil, to cool the air. This cycle repeats until enough heat is taken out of the air in your home so that the temperature matches what is set on your thermostat.

Maintaining HVAC Coils for Optimal Performance

Dirt or dust buildup on the coils can act as insulation, keeping the heat in and the air away, resulting in your system working harder to heat or cool the air. If the coils get dirty, the refrigerant running through it won’t be able to warm up as much, which can cause the water to freeze, reducing efficiency, capacity, or both. Change your air filter regularly to keep excessive dust free from the coils.

Having your coils serviced and cleaned once or twice a year by a licensed HVAC technician will help your system run more efficiently and at the temperature you desire. 

Reach out to a Lennox Dealer near you to ensure regular maintenance of your HVAC coils.