Before you start cleaning your AC unit, it helps to understand a bit about how the system works. Air conditioners have an indoor component and an outdoor component, and each contains a different type of coil you’ need to clean.
You will find evaporator coils in the interior portion of the unit. These coils are usually made of copper, which conducts heat easily, and they contain coolant. The coils absorb heat as warm air passes over them, and the refrigerant evaporates to a gas state.
From there, the refrigerant transfers the warm air to the outside unit, where it passes through the compressor to the condenser coil. At this point, the compressor returns the refrigerant to a liquid state. The condenser coil then releases heat into the surrounding air with the help of an exhaust fan.
In order to clean your air conditioner, you have to work on both the indoor and outdoor components of your unit.
How to Clean Your AC Unit Inside?
It’s up to you whether you want to start with the outdoor or indoor portion of the unit. We’ll begin with directions for the inside portion.
1. Turn Off the Power to the Air Conditioner
Air conditioners have a lot of moving parts, and because safety is paramount, you should turn off the power at your breaker box. This means you won’t have any lights, so this is definitely a daytime project. If your indoor unit is somewhere dark, like the attic, you will want to set up adequate lighting.
2. Open Up the AC Unit
Your blower unit will have a door to the evaporator coil. Depending on your unit, you might have to remove the foil duct tape. There are often a few bolts or screws holding the door in place.
3. Clean the Air Conditioner Evaporator Coils
If you have a soft brush, use it to remove dust from the coil. This dust will consist of whatever particulates populate the inside of your home. This includes skin cells and sometimes pollen, so if you’re prone to allergies, you may want to wear a mask.
The best cleaning solution is a no-rinse coil cleaner you can buy at your local home improvement store. This spray foams up and then drips into the unit’s drain pan, taking dirt and dust with it. Spray the foam on as evenly as you can, and get it in all the small areas you can’t reach by hand.
The best time to do this is on a warm day so that when you turn the unit back on, the AC condensation rinses off the coils.
4. Clean the AC Drain Pan
Once the coil cleaner has completely done its job, clean out the drain pan. Soap and hot water are good places to start, and bleach helps with sanitization. Go for a 50/50 mixture of bleach and water. Pour the solution down the drain to make sure it’s clear.
If you want a longer-term way to keep your drain from growing algae, you can purchase AC drain pan tablets at most home improvement and hardware stores.
5. Clear the Air Conditioner Drain If It Is Plugged
If your bleach solution washes easily down the drain, you can skip this step. If it’s sluggish, your drain may be plugged. Without regular cleaning and maintenance, mold and algae can build up in the drain. It’s usually a PVC pipe around an inch wide, so it doesn’t take much buildup to clog.
Your drain may end outside, often around the condenser unit. Otherwise, it will let out into a utility sink or a drain in the basement floor. If your unit is in the attic, it may drain down one of your exterior walls. Follow the drain to where it ends and bring a wet/dry vacuum with you. If you are concerned about soiling the filter, you can remove it from the vacuum.
Take the vacuum hose and hold it to the end of the drain tube. You can prevent air leakage by holding a towel around the gap. If you want the tightest seal, duct tape the hose and drain together. Turn on the vacuum and let it run for two or three minutes to clear out any buildup that has accumulated.
6. Close the AC Access Panel
Reattach the access panel, using the same screws you took out in the beginning of the procedure. If you have HVAC metal foil tape, use it to seal the top and bottom of the access panel. Don’t cover up the manufacturer’s label, as a technician may need it to perform maintenance or make repairs on the unit.
This is all you need to do for regular cleaning, but you may encounter challenges you can’t handle on your own. If you have A-frame evaporator coils, you may find parts you can’t access because the coils are enclosed on both ends. If you haven’t cleaned your A-frame coils in a while, there’s a good chance you will need to enlist the help of professionals to get them completely clean.
How to Clean Your AC Unit Outside?
Keeping your air conditioner’s condenser coils clean and free from debris can allow your unit to run more efficiently and extend its lifespan. Many people choose to clean their air conditioners in the springtime, ensuring it is in top condition just before the heat of summer hits.
Here are a few steps on keeping your outside unit clean and keeping your system running efficiently for the warmer season and avoiding costly AC repairs.
Step 1: Disconnect Power.
Most central air conditioners are equipped with a shutoff box next to the unit itself, as shown above. Depending on your unit’s brand and model, you may need to pull out the shutoff box, remove a fuse, or flip a switch to shut the power to the unit. If your particular heating and cooling unit do not have a shutoff box, turn off the power from the circuit breaker panel that controls your unit.
Step 2: Trim Plant Growth.
Make sure that any grass, weeds, bushes, or other foliage are trimmed a minimum of two feet away from your unit to prevent them from getting inside.
Step 3: Detach Outer Case.
Depending on your type of unit, you will either need a nut driver or a screwdriver to remove the outer casing or access panel.
Step 4: Remove the top of the AC.
You may need to lift the fan assembly off your unit in order to remove the top of the air conditioner. If so, be careful not to stretch and damage the fan wires.
Step 5: Clean & Lubricate Fan Assembly.
Use a rag, broom, or shop vacuum to clear any dirt and debris that have accumulated on the fan motor and shaft. This is also a good opportunity to apply a small drop of oil to each lubrication port in your motor. If your unit does not have lubrication ports, skip this step.
Step 6: Brush Away Dirt.
Using a brush or a broom, gently brush away dirt from the coils.
Step 7: Spray Clean Coils.
Trapped dirt can be sprayed away with just water, while more substantial dirt may require you to use a biodegradable foaming cleaner. Always cover any wires or motors with plastic before you spray! Spray the coils from the outside and allow them to soak for about 15 minutes, repeating as necessary. Rinse away any remaining cleaner from the coils until the runoff is clear. Do not power wash your coils, as this will damage your unit.
Step 8: Inspect for Damage.
If any coil fins are bent, they can be combed straight using a special “fin comb” which can be purchased at any air conditioning supply store.
Step 9: Reassemble.
Make sure that you get all the screws back on! Now you can turn back on the power and enjoy your nice, clean unit.
How to Clean Your Air Filter?
Air conditioning units don’t require a lot of maintenance, but it’s important to clean or replace your unit’s air filters regularly to reduce the likelihood of airborne mold and common allergens through forced air systems.
There are different types of air filters available, and though many are disposable and can’t be cleaned, thanks to changes in technology and related efficiencies, washable air filters are more common than ever. If you’ve previously used disposable filters, this might even be the perfect time to upgrade.
Step 1: Turn Off Your AC Unit
Keeping the unit off ensures that you’re not letting dirty air circulate through your home while the filter is being cleaned.
Step 2: Remove the Filter
Some units can have multiple filters, so be sure you check all vents.
Step 3: Vacuum the Filter
To reduce the amount of dusty buildup, the first thing you can do is use a hand vacuum to lift allergens. Use the microfiber cloth to clean any dust along the frame. Getting this top layer of sediment and anything loose makes the next step clean and easy.
Step 4: Wash the Filter
In a deep sink or outdoors with your hose, rinse the filter gently and thoroughly, and allow it to dry. If you need to provide a deep clean, soak the filter in a flat bin with 1-part white vinegar and 1-part warm water for an hour, and then rinse it gently with the hose.
Never use a pressurized cleaner on an air filter; they’re simply too delicate for any high-pressure hose.
Step 5: Reinstall the Filter
Check the dry filter for any signs of damaged holes, dirt that could not be cleaned thoroughly or rips in the material. If it’s in good condition, you can put it back in the unit. Refer to any expiration dates on the product or its original packaging to make a note of when it needs to be fully replaced.