How to Clean an Outdoor Air Conditioning Coil (Trane unit example)

September 13, 2011 | by Ethan (email) |

Twice in five years I’ve cleaned my outdoor AC condenser, and both times I’ve been amazed by the amount of dirt and  leaves I’ve found. Fortunately, cleaning your outdoor coil is a task that any homeowner can accomplish, and it doesn’t take very long. A good cleaning will help your AC unit to function more efficiently, and potentially make it last longer too. Read on to learn how I removed the fan, outside panels and scrubbed away a lot of dirt and debris from my outdoor AC condenser.

Editors note: This post originally ran in August 2009. In a related post about AC maintenance, one reader asked about cleaning an outdoor condenser unit, which prompted us to update this post with more pictures and information. If you find it helpful, give it a +1. Else, leave a comment and we’ll try to make it better.

Outdoor Condenser Coil

The coil transfers heat from your home to the outside, and this process works best when air can move freely. That’s why outdoor units have those big ‘ol fans. When dirt and leaves block up air passages, it’s that much harder to cycle enough air. Plus, dirt and even dust can settle on the AC fins making them much less efficient. This in turn raises operational costs and shortens the lifespan of your compressor.

How to Clean your AC Unit (Trane XE1200 as example)

This project doesn’t require much in the way of tools. You’ll need a nut driver to remove some metal screws, a hose, and a scrubber. I’ve got a handy brush that allows me to attach the hose and pump water through the bristles. Cleaning my condenser is pretty much the perfect application for it.

Cleaning the Unit
It’s best to start by turning off the breaker supplying power to the unit, and hopefully your panel is labeled better than mine. Next, remove any nearby obstructions. Most installation manuals will let you know the minimum clearance around and above the unit. If you don’t have access to the manual, try for at least two feet.

My unit has louvered sides held together with a lot of metal screws, and I’d estimate I removed about 30 screws all together. Fortunately, they’re all the same. Just keep track of where they all go. If your unit has a grill instead of louvers, don’t even bother taking the sides off. You can effectively clean everything as is.

You’ll see screws around the perimeter, at the corner where the top and sides meet (not the screws circling the fan). After you remove all those screws, the top (and fan) can be lifted off. Be careful because the fan is tethered with electrical wires. If the installers had any sense, they left a generous length of wire and you can lean the top nearby.

This picture shows the electrical compartment.

And here you see the compressor.

The side grills have more screws at all the corners and along the bottom edge. After you remove these screws you’ll see how the sides overlap and can be lifted up and off. It’s a good idea to remember where each panel was located. They should be identical, but this’ll help ensure that screw hole line up when you put it back together.

Use your hose and brush to clean the grills, and hose down the fins (do not scrub the fins!). The fins maximize surface area for the heat exchange so if you accidentally mash them together, they won’t work nearly as well. Even an invisible layer of dust decreases efficiency so run your hose over everything (except the electric).

I think this was the beginnings of a nest.

You can see the fins and a few places where the fins are bent- probably from when the previous owner had the compressor replaced.

This shows some of the gunk I found on the fins.

And here’s everything bright and clean.

Tips for Cleaning Your AC Unit

• Some of the parts are heavy or awkward. A second pair of hands is a good idea.
• Compressed air can be useful to clean around electrical parts. It’s also a good alternative if you can’t use a water hose.
• You can also spray your coil with a cleaning solution such as AC cleaner or soapy water.

What do you think? When was the last time you cleaned your outdoor unit?