How to clean your AC coils like an HVAC technician
Cleaning your AC coils is easy, effective, and saves you money.
Is your AC running all of the time or not cooling as well as it should? There’s a good chance you have dirty AC coils. As you run your AC, debris slowly builds up on your coils, making it harder for your AC to cool your home. A quick cleaning will do wonders for your comfort and your utility bill.
NOTE: Cleaning air conditioner coils is not difficult, but please don’t do it unless you feel comfortable working around your AC system. It is a serious piece of machinery and you can get hurt if you aren’t careful.
Tools & materials needed:
- Reversible hex chuck + impact driver or a set of SAE nut drivers (need 1/4” & 5/16” specifically)
- Bristle brush
- Access to water & water hose (if cleaning condenser coil)
- No-rinse evaporator coil cleaner (if cleaning evaporator coil)
Homemade AC coil cleaner
If you don’t want to buy specialized coil cleaner, you can mix warm water with detergent and put it in a spray bottle. It won’t work quite as well, but it’s easy to make, cheap, and readily available in most every home.
How to clean an AC evaporator coil
The steps below describe how to clean an evaporator coil without removing it from it’s housing. The vast majority of coils can be cleaned in this manner. That said, if your coil is so dirty that it needs to be removed, you will need to call a professional HVAC technician. Removing a coil is labor intensive and involves removing refrigerant, which is a federally regulated material, not to mention dangerous to handle.
1. Turn your AC off at the breaker panel. First things first, let’s make sure your AC is off. To do that, go to your breaker panel and find the switches that control your HVAC system. Usually you will have two, one labeled AC and the other labeled furnace. Turn them both off.
2. Locate your evaporator coil. Your evaporator coil is typically in the attic but may also be in a closet or crawlspace. You’ll be looking for something that looks like the below picture. Once you find it, move on to the next step.
3. Take off your coil’s access panel. Your evaporator coil is hidden behind a panel secured by a few screws. Remove them and take off the panel.
4. Remove any hair on the coil. If you have pets, you may find a good bit of hair on your coil. No big deal, just use a soft bristle brush to gently remove it. Be careful not to cut yourself while doing so as the coil fins are quite sharp.
5. Clean with coil cleaner. There’s not much to this part, simply spray the coil cleaner over as much of the coil as possible. Let the foam do the work. Always wear gloves while handling coil cleaner as it is acidic and can hurt you.
6. Wash with water. Despite it’s name, evaporator coil cleaner should still be rinsed off after using. If it’s warm enough outside to run your AC, you can simply turn your AC on because the condensation produced by running your air conditioner will rinse the coil cleaner off. If it’s too cold to run your AC, just take a spray bottle and spritz water on your coil.
7. Reinstall the coil panel and turn your AC back on. Voilà! Your AC should now cool better and more efficiently.
How to clean an AC condenser coil
The below steps describe how to clean your outside AC coil (technically called a condenser coil). Cleaning it is not too difficult, just take your time and be careful not to damage the fins of the coil.
1. Turn your AC off at the breaker panel. For safety, start by turning your HVAC system off at the breaker panel. You probably have two switches, one labeled AC and one labeled furnace. Turn them both off.
2. Take your panels off. If you want a truly deep clean, you need to take the panels off your air conditioner. Doing so isn’t hard, but it does take a little bit of time to locate and remove all of the screws. Easy route: If you don’t want to go through the trouble of removing your panels, a quick rinse of the coil with a garden hose will take some of the debris off.
3. Thoroughly wash the coils with water. Professionals typically rinse condenser coils three times: once from the inside, once from the outside, and one last time from the inside to get any debris that made its way inside after the previous wash. Be careful not to bend the coils, using only regular water pressure out of a garden hose during the cleaning. Never use a pressure washer — the high pressure will flatten the coil fins and ruin your AC.
4. Reinstall the panels and turn your AC back on. After cleaning the coil, put your panels back on the same way you took them off. Then, go back to the breaker panel and turn your AC back on. You did it!
Does cleaning AC coils really help?
Yes. Cleaning your AC coils is one of the most helpful things you can do for your air conditioner. A system with clean coils will cool better and run less, saving you money. Past utility studies have found regular AC maintenance (of which cleaning coils is the most important part) improves AC efficiency up to 30%. Depending on where you live and the type of AC you have, that could mean saving hundreds of dollars a year.
How do AC coils work?
AC coils work by absorbing and releasing heat, thereby cooling your home. The basic process goes something like this: your home’s hot air is passed over the evaporator coil, which removes said heat and transfers it to refrigerant. The hot refrigerant then travels outside to your condenser coil, where the heat is removed from the refrigerant and released into the air. The now cool refrigerant then travels back to the evaporator coil inside to repeat the process.
What is an evaporator coil?
The evaporator coil is what removes the heat from your home’s air. As air is blown over it, the cold refrigerant in the evaporator coil absorbs the heat from the air. The hot refrigerant then travels outside to your condenser to be cooled (the part of your AC system that sits outside). Location wise, your evaporator coil is typically inside, either attached to your furnace or, if you have a heat pump, inside the air handler.
What is a condenser coil?
The condenser coil removes heat from your refrigerant, so that is can be sent back to your indoor system to pull more heat out of home’s air. It’s part of your outdoor AC unit, which is technically called a condenser. If you’re looking at a condenser, you’ll usually see a metal cage and then right behind that, a bunch of little metal fins. That’s the condenser coil.
How often should you clean your AC coils?
Recommendations differ but a once a year deep clean is fine for most situations. If you have pets or you live in a high pollution area, you might step it up to twice a year cleanings.
What do professionals use to clean ACs?
Professionals clean AC coils basically the same way as described above, with coil cleaner, a soft bristle brush, & water. The only difference is that an AC technician has the ability to remove the evaporator coil if need be.