Air conditioning coil cleaning is an important air conditioning maintenance procedure that sometimes takes some patience, and usually takes a lot of water.

First, you have to make some common sense evaluations.

• Can you wash the coil right where it is?

• Is there anything under it that needs to be moved or covered or protected?

• Is it so dirty that it will need several treatments with a foaming type of cleaner?

• Is there a floor drain under it where the water will drain?

• Would it actually be more efficient to pump the system down and take the coil outside for cleaning?

You will have to make sure that the water you use will drain to somewhere acceptable. If there is no drain, run a wet/dry vacuum cleaner and vacuum the water as you wash and rinse the coil.

Let’s get down to the air conditioning coil cleaning procedure.

Wherever the coil might be, if it’s plugged up with mold and other assorted microorganisms, spray it thoroughly with a foaming coil cleaner, and wait for the cleaner to work for a few minutes.

Rinse it off thoroughly, and inspect the coil. You may have to repeat this procedure several times, or many times, to get a plugged coil clean.

How can you tell if the coil is clean?

On coils up to about 20 tons, you should be able to see light through the coil, unless it is an extra thick design. On extra thick designs, doubled coils, or larger commercial coils, you might not be able to see light through the coils. In that case, if your water goes straight through the coil and comes out clean, my experience has been that the coil is clean.

Once again, use some common sense.

A coil may have never been thoroughly cleaned until you arrived to troubleshoot poor cooling, so you have to make up for poor, or no, prior air conditioning maintenance.

If possible, let the owner see the stuff washing out of the coil.

They always get a funny look on their face, and usually make a stronger effort to have their air conditioning coil cleaning done on a more regular schedule.

Air conditioning coil cleaning is messy, and can be a hassle, but if you’re a pro who can get a customer’s system cooling efficiently just by cleaning it, without telling them they need expensive parts, you’ll be the pro they want to talk to when something does break. (As long as you didn’t ruin their carpet, or parquet floor, or wall paint, or furniture, or lawn, etc.)

Publication date: 04/04/2011