A central air conditioning unit can be one of the biggest investments you’ll make in your home. The average cost of a new central air conditioner is about $5,043, according to a survey by Angie’s List. The good news is that quality central air conditioning units can last 10 to 15 years, if properly cared for.

Air conditioning units require some basic cleaning and maintenance that homeowners can do themselves. It’s a good idea to clean and inspect your air conditioning unit twice a year, once at the beginning of the summer months, and once at the end. Cleaning your air conditioner involves removing dirt and debris from both the outside and inside of the unit, and cleaning or changing the air filter. You should also make sure that air flow into the air conditioner remains unobstructed, and that it’s not being exposed to any potentially corrosive elements.

Clean the Exterior of the Air Conditioning Unit

Before you begin cleaning your air conditioning unit, turn it off. You may have an on/off switch on your unit, but if not, you’ll need to turn off the unit at the breaker box. This protects you from electric shock while you’re working on your unit.

Start by examining the outside of your unit. Remove any leaves, twigs, lumps of dead grass, or other debris from the outside of the unit. Debris on the outside of the unit can hamper airflow, forcing your air conditioner to work harder and shortening its lifespan. Once you have removed any debris from the outside of the unit, go ahead and spray it with a garden hose to remove any exterior dirt.

Clean the Inside and Change the Air Filter

Next you’ll want to access the inside of the air conditioning unit so you can service the condenser. Remove the nuts, screws, or clips that hold the exterior protective grille in place. Once you have removed this grille, you should be able to see the condenser coil.

Remove debris from the condenser coil by carefully vacuuming it with a soft, bristle-brush attachment on a shop vacuum. The fins are delicate, so take care not to damage them. Once you have vacuumed the condenser coil, remove the covering at the top of the condenser. This protects the condenser’s fan, which may or may not be attached to the protective covering itself. Use a damp cloth to wipe the fan’s blades clean.

Now, it’s time to change the air filter. Some units have disposable cardboard filters that need to be entirely replaced, but others have reusable filters that can be washed out. If your unit has a metal and plastic filter, there’s a good chance it’s meant to be washed and reused.

To find the air filter, look for a slot inside your home, usually at the place where the return air duct from the air conditioner enters your furnace’s blower chamber. Most central air conditioners make use of your central heating’s blower and ductwork. If you have a reusable filter, you can wash it outside, using your garden hose. If it’s a disposable filter, just throw it away and replace it with a new one. If you are changing your air filters often enough — every 90 days or 60 days if you have pets – you’ll find that the condenser coils and fan blades inside the air conditioner stay much cleaner, and may not even need to be cleaned annually.

Check for Obstructions

Before you turn your air conditioner back on, make sure that nothing is blocking the air flow into the unit outside. Any bushes, trees, vines, or fences should be planted far enough away from the unit to allow air to flow freely into it.

If you have a dog or there’s a dog in your neighborhood, you may want to erect a small fence around your central air conditioning unit. That’s because dog urine can corrode and damage the condenser coils inside the unit, and you may end up needing to replace them. If you see any signs of corrosion on your condenser coils when you clean them, consult our service department.

Before you turn your air conditioner back on, you may need to let it warm up. If you’ve had the air conditioner turned off for more than four hours, turn off your thermostat, restore power to the air conditioner, and let it warm up for at least 24 hours before turning your thermostat back on. This way, heating elements inside the condenser will have a chance to re-warm the lubricating oil that the condenser needs to function.

Central air conditioning units require cleaning and maintenance, just like any other part of your home. You can clean debris from your air conditioner yourself, but make sure to call us for regular maintenance. Keeping your air conditioner clean will lower your electricity bill, and extend your unit’s life.