The Importance of a Clean Indoor HVAC Coil

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In a previous blog, we discussed how having a clean outdoor coil helps you achieve maximum air conditioning capacity and energy efficiency, which in turn means lower operating costs. However, this is only half of the equation for your air conditioner—you also have an indoor coil that you depend on, known as your evaporator coil.

What Does the Evaporator Coil Do?

Your evaporator coil is located in the large box that is your indoor unit. Just like your outdoor coil, the evaporator coil’s main job is to transfer heat. Only unlike your outdoor coil that’s responsible for shedding heat and expelling it into the atmosphere, the evaporator coil’s job is to absorb the heat, sucking it out of the air around you so it can be absorbed by the refrigerant that runs through it. Once it does, the refrigerant is then pumped outside where the heat dissipates, and the cycle starts over.

However, your indoor coil also has a second job that the outdoor coil does not—dealing with humidity. Your indoor coil turns water vapor in the air that passes over it into a liquid form through a process known as condensation. As water vapor makes contact with the cold coil, it condenses into water, which then accumulates and builds on the coil’s surface. Once it grows in size, it turns into drops, and as those drops accumulate they begin to drip out of your air conditioner, and then out of your building through your condensation drain. This is how air conditioners also dry out the air that they cool.

Maintaining Your Evaporator Coil

One of the major differences between your indoor and outdoor coil is the protection they are afforded. Your outdoor coil essentially has no protection, and the air that passes over it is unfiltered. Conversely, your indoor coil is protected by an air filter. This is because the air that circulates over this coil is also then sent back into your home once it’s cooled. Straining the air with a filter helps improve your indoor air quality, and helps keep your indoor coil cleaner.

However, this also means that one of the reasons why your indoor coil can get dirty is because your air filter has either filled up or is not properly installed. Another reason why this can happen is that your return ducts are not properly sealed. Some systems have your air filter positioned in a way that seals the space between the filter and the equipment. However, as the motor turns and the fan pulls the air through, a small crack or hole could pull in unfiltered air which then causes the coil to become dirty.

How to Clean a Coil

A dirty indoor coil has many of the same effects on your home as a dirty outdoor coil—it leads to inefficient cooling, heavy energy usage, and much greater strain on your system through longer and rougher cycles. Thus, keeping it clean is important. Likewise, a dirty coil can continue to allow dust and dirt to swirl throughout your home.

In most cases, your air filter does its job and keeps the coil clean so your system works as intended. However, it can only do this so long as the coil stays clean. Over time, any coil is going to get dirty, and that means you should clean it. Your indoor coil should be inspected at least once per year as a part of your annual maintenance service, and we recommend having it cleaned every 3 to 5 years.

Schedule your maintenance service by calling the experts at Standard Heating, Cooling & Plumbing! Our Birmingham HVAC professionals have proudly served the entire metro area with quality HVAC services for both homes and business since 1939. 

Call us at (205) 386-4001 today or contact us online if you would like more information about our maintenance plans.

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