How to Clean an A/C Condenser Coil

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Improve air conditioning efficiency by cleaning your A/C condenser coil.

Cleaning an A/C condenser coil is a major part of keeping a system efficient. The condenser coil is part of the condensing unit which sits outside. A dirty coil can greatly decrease efficiency. Efficiency goes down when a coil gets dirty because more and more heat transfer is lost as a coil gets plugged. An air conditioning system works by absorbing heat in the coil inside and getting rid of heat in the condenser coil. The better the heat transfer at the condenser the better the efficiency of the system.

plugged condenser coil

A plugged condenser coil can cause all kinds of problems. Pressure in the condenser coil will increase and possibly trip a high pressure switch that will shut down the air conditioner. If the unit does not have a high pressure switch the unit will continue to run at poor efficiency with the possibility of permanently damaging the compressor. A completely plugged condenser coil offers virtually no cooling.

dirty and clean condenser coil

Some plugged condenser coils are easy to spot. Coils can be plugged even if there is not a blanket of dirt on the outside. One way to tell if a coil is plugged is to hold your hand over the top of the condenser fan. If the coil is clean the air will be blowing straight out. If the coil is plugged it will blow out more to the side. If you can't tell just clean it.

Cleaning a A/C condenser coil is a fairly easy task. Some condensing unit have screens around the coil that need to be removed. A chemical foaming cleaner is also recommended once a year. Coil cleaning should be done about once a month when the air conditioning is in use, but just once a year with the chemical cleaner. Cotton wood gives coils the most problems. If a condenser coil is near cotton wood, it may need to be cleaned more frequently.

coil cleaner

How to Clean an A/C Condenser Coil

1. Set thermostat to off and turn power off at disconnect by condensing unit.

2. Remove any covers or screens blocking condenser coil.

3. Use a hose with a spray nozzle and jet stream.

4. Start at the top and work down the coil going side to side with the water stream at a downwards angle. Clean the coil in sections.

5. Apply coil cleaning spray and repeat step 3.

Note: If a hose and water is not an option, use compressed air or CO2 to blow out coil. Just be careful not to bend fins.

1 comment

Donata L.
Posted on Sep 16, 2011