Air Conditioner Evaporator Coil Cleaning

Posted on: November 24, 2016
By: Alan O'Neill
Posted in: Air Conditioning

Air Conditioner Evaporator Coil Cleaning For Houston Homeowners

Many people mistakenly assume that the frigid refrigerant circulating through the evaporator coil adds coolness to the air in your home. Actually, it extracts heat energy. After the heat energy is removed from the air, coolness is just what’s left behind. Anything that interferes with the transfer of heat from the air to the refrigerant, such as a layer of dust or dirt on the coil surfaces.

This video shows Air Conditioner Evaporator Coil cleaning.

How to Clean Air Conditioner Evaporator Coils

In these systems, the refrigerant becomes a liquid when compressed and evaporates when released from the pressure. Your evaporator coil releases pressure from the refrigerant allowing it to evaporate. This is when the gas that is released gets really cold and absorbs the heat coming from your return ducts. After the gas gets warmer, it gets sent to the condenser coils where it releases the heat to the air outside.

After releasing the captured heat from the home outdoors, the cooled liquid travels back to the indoor unit, where the process begins all over again. So what exactly happens? The heat from your home gets captured by the evaporator coils inside and then gets distributed outdoors.

Since the evaporator coil is installed directly in the airstream of your system, it’s a magnet for accumulation of dust or other contaminants. An annual inspection of the evaporator coil is critical. The external surfaces of the evaporator coil that face the airflow in the duct are accessible and cleaning is generally within the skill level of most do-it-yourselfers. However, if dust or dirt contamination is so extensive that the inside coil surfaces are affected, too, schedule a more extensive, heavy-duty cleaning procedure with your HVAC contractor. Here’s a basic primer on how to clean air conditioner evaporator coils.

1. Purchase a can of commercially available no-rinse coil cleaner. This is normally a foamy substance in a spray can that is applied directly to the coil surfaces.
2. Locate the air handler unit, usually installed in a closet or attic. 
3. Turn off power to the air handler at the main switch or circuit breaker.
4. Remove the metal reflective tape that seals the seams around the coil access panel.
5. Remove the screws that secure the coil access panel to the air handler. 
6. The evaporator coil is configured in an A-frame design with two sides. Examine the external surfaces of the coil for dirt or dust residue. Also be alert to any signs of mold growing on the coil. Mold contamination will need to be treated by your HVAC contractor using biocides approved for use in cooling systems.
7. Spray the coil cleaner on all exposed surfaces of the coil. Allow the cleaner adequate time to soak in and drip down into the condensate drain pan below the air handler. 
8. While the cleaner is soaking the coil, examine the drain pan. Look for any evidence of mold growth or algae. Minor contamination can be treated with a 50/50 mix of bleach and water. Severe contaminations, however, should be addressed by your HVAC contractor.
9. Pour some water down the condensate drain tube that leads away from the drain pan to verify that the tube is open and drains properly. If you see evidence that the condensate drain tube is blocked, such as standing water in the drain pan, discontinue use of the A/C and call your HVAC contractor to clear the blockage.
10. After the coil cleaner has dripped off the coils, examine the coil surfaces for any areas that may need another application of cleaner and re-apply as necessary.
11. Reinstall the coil access cover and tighten the screws. Tape the seams around the access cover with metal tape. Restore power to the air handler and turn on the system to generate condensation on the coils for additional rinsing. 

Purpose Of Evaporator Coil

The evaporator coil works by drawing hot air over the coil, which is filled with refrigerant, to cool the air. Once air has passed over the evaporator coil, a fan is used to circulate the cooled air throughout the house. The evaporator coil is located inside the house. Call (713) 812-7070 us for your home service and repair needs.

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