How To Properly And Safely Clean The Evaporator Coils In Your Central Air Conditioner

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Before summer heat hits, you will need to take a closer look at your air conditioner's evaporator coils to see if they need cleaning. If they do, then you can safely clean them yourself as long as you pay attention to a few key details. Below is what you need to know and how to properly clean the evaporator coils in your central air conditioning unit:

What evaporator coils do and why keeping them clean is important

Your home's central air conditioner contains two sets of coils: condenser coils and evaporator coils. The condenser coils are located inside the outdoor unit that also houses the air conditioner compressor. The evaporator coils are inside the air handler, which is the indoor unit containing the blower that moves air through the ducts.

Evaporator coils perform a simple, but critical role in cooling your home. Refrigerant is pumped through the tubing inside the evaporator coils, and it absorbs heat from the ambient air that surrounds them. This cools the air and also removes moisture at the same time, since cooler air is unable hold as much water vapor as warmer air. The water vapor condenses on the evaporator coils and is drained from the unit.

It is important that evaporator coils be kept clean. Dust, dirt, pollen, dander or any other foreign debris are insulators when clinging to coils, and as a result, the necessary heat exchange between refrigerant and the air does not occur as it should. Bare coils are able to facilitate this exchange at a high level of efficiency.

How to clean your evaporator coils safely

Evaporator coils are fairly delicate equipment and are protected by a sheet metal cabinet in most air conditioning systems. An accidental blow can damage fins or puncture tubing, allowing refrigerant to escape, and the on-site repair of modern aluminum evaporator components can be difficult or even impossible. Not only that, but the thin, connective coating essential for heat transfer between fins and tubing can be damaged by harsh chemicals. Spraying or washing the coils with the wrong substance can cause expensive damage.

When cleaning evaporator coils, it is necessary to have the correct chemicals and tools available for use. You will need the following items:

  • Spray bottle filled with water and evaporator coil cleaner - Approximately half the bottle should be filled with water with the rest consisting of coil cleaner. Be sure to choose a proven safe, established brand of coil cleaner; never experiment with homemade coil cleaners that may cause serious, expensive damage to equipment.

  • Spray bottle filled with distilled water - Regular tap water contains minerals that can leave hard water stains.

  • Paper towels or cotton shop towels

  • Flashlight

Step-by-step procedure

1. Disconnect the power to the central air conditioning system - Before beginning, turn off the power to the entire central air conditioner at the circuit breaker panel. Leaving it connected could result in potential shock hazards or cause damage to the unit should it be activated. Be sure not to misplace the power disconnect handle.

2. Open the access panel to the evaporator unit - Locate the air handler unit, which is often in an attic or tucked behind an interior doorway, and remove the access panel that covers the evaporator. Using a flashlight for visibility, take a look at the evaporator coils and the surrounding area inside the unit. Make a mental note of any damage you see and contact a qualified air conditioning professional for assistance if necessary.

3. Spray the evaporator coils with cleaner - After inspecting the coils for damage, you will need to spray them with an approved coil cleaning solution. Be sure to thoroughly saturate the coils and allow the solution to soak deep into the fins and tubing.

4. Rinse the evaporator coils with water - Once the coils have soaked for several minutes, your next step is to rinse off the evaporator coils with water to remove the cleaner. The water will run off the coils and into the condensate drain pan. Keep an eye on the pan to be sure it isn't overflowing and check the drain line leading from the pan to remove clogs.

5. Wipe clean and dry - When the evaporator coils have been soaked and rinsed, you can use an old towel to clean off the interior of evaporator unit and remove loose dust. If there are any pools of cleaning solution or water, simply dry them up with paper towels.

For more information or if you need help with maintenance for your AC unit, contact a local HVAC company like Century Heating & Air Conditioning Services