Air conditioning systems have two coils that work in tandem to remove heat from within the building and then release it outside. The condenser and evaporator coils are two of the most important parts of an AC system and need to be cleaned regularly for the system to work effectively. In this article, we’ll explain what role each of these coils plays and why cleaning them regularly is so important.
Understanding the Role That AC Coils Play in Cooling
The evaporator coil is the primary indoor component of a central AC system. When an AC system runs, warm air is blown over this coil, and the cold refrigerant pumped through the coil naturally draws and absorbs heat out of the air. Ductless mini-split systems also have an evaporator coil in each of the indoor air handlers or head units, which work the same way.
The second coil is the condenser coil, which is located outside the AC condenser unit. Before the refrigerant gets pumped into this coil, it is first condensed. Condensing the refrigerant instantly increases its pressure, which in turn increases its temperature and causes it to boil and change into an extremely hot gas. As the fan in the AC condenser blows air over the condenser coil, most of the heat stored in the refrigerant is released into the air.
Why Dirty Coils Are Such an Issue
Evaporator and condenser coils consist of a series of aluminum or copper tubes that the refrigerant flows through. These tubes are surrounded by thin strips of metal known as fins, which help transfer heat to or away from the refrigerant tubes. The fins in an evaporator coil draw heat out of the air and transfer it to the tubes, while the fins on a condenser coil capture heat from the tubes and transfer it into the air.
The refrigerant tubes and the fins tend to collect lots of dust and debris over time. Condenser coils are especially prone to collecting lots of dust and dirt since they’re located outside, but evaporator coils can also get fairly dirty. Another issue is that mold, mildew, and bacteria can sometimes grow on an evaporator coil. This happens because the coil is often damp due to all of the water that condenses on it as the AC cools.
Buildup on an evaporator or condenser coil creates a layer of insulation that interferes with the heat transfer process by preventing the fins and tubes from capturing or releasing as much heat. If the evaporator coil isn’t capturing as much heat as it should, the refrigerant flowing through it can make it so cold that the condensation starts to freeze. When this happens, the system will stop cooling altogether since the ice prevents the coil from capturing any heat.
If the condenser coil is dirty, it makes it far more difficult for all of the heat to flow out of the coil into the air. That means the refrigerant will still contain a lot of latent heat when pumped back into the evaporator coil. This also leads to the system cooling more slowly since the warmer refrigerant won’t be able to draw in and hold as much heat. If the system can’t release all of the heat, it can cause the AC condenser to shut down due to overheating.
DIY vs. Professional Coil Cleaning
While some coil cleaning sprays are available, these are mostly meant for window or portable air conditioners. Cleaning the coils in a central AC or mini-split is a job that should always be done by a certified AC technician. Part of the reason is that you could easily damage the fins or put a hole in the coil, leading to the system leaking refrigerant. Another issue is that cleaning the condenser coil usually requires first removing the entire fan assembly from the AC condenser unit since this is the only way to access the coil. Trying to do this yourself is not recommended since you could easily damage the fan motor or wiring.
Since 1945, WK Mechanical, Inc. has provided reliable air conditioning and heating services in Middletown and the Hudson Valley area. We offer expert maintenance services and are ready to help with coil cleaning and all of your other maintenance needs. For more information on the importance of coil cleaning or to schedule any HVAC maintenance, repair, or installation service, contact us today.
