Menu

Why You Should Wash Your AC’s Outside Unit Before Summer Starts

August 04, 2016

Summer’s coming quickly (thank goodness). But is your air conditioner ready?

If it’s like most AC units in Kansas City, it probably isn’t because it hasn’t had its outdoor coil cleaned.

And ignoring this maintenance task can cost you in 2 ways:

We’re going to show you why this is and how to clean the coils yourself (if you’re so inclined).

How a dirty outside unit increases your electric bills

Dirt on your outside unit makes it more difficult for your air conditioner to remove heat from your home. So it has to work longer and harder, which can cause the AC to break down and increases your electric bills.

You see, your air conditioner works like a heat sponge by absorbing heat from inside your home and dumping it outside. Your AC does this by using refrigerant to absorb and carry the heat outside.

An abstract image

The air conditioning process, simplified, by Energy Vanguard

And once in the outside unit, here’s what happens:

  1. The hot refrigerant flows through an array of metal tubes (called the condenser coil). 
  2. A fan pulls outside air over this coil, allowing the air to absorb heat from the refrigerant. 
  3. The refrigerant then cools and returns to the indoor unit, restarting the cycle.
A cute kitten

The inside of the outdoor AC unit showing condenser coils via inspectapedia

An abstract image

An outside unit with cover removed showing a dirty coil via Air Repair Pros in Texas

That dirt is an insulating barrier between the refrigerant-filled coils and the outdoor air, preventing the refrigerant from releasing heat. (Think of it like wearing a thick jacket in summer, making it hard for your body to release heat.) 

Leaving this insulating barrier on the AC unit creates a chain reaction that destroys your AC’s energy efficiency:

  1. The refrigerant can’t get rid of as much heat outside so...
  2. When it returns to the indoor unit, it can’t absorb as much heat
  3. This increases the temperature of air coming out of your vents (by as much as 5 degrees, according to the study by SEC)
  4. Since air isn’t getting as cold, your AC has to run longer to provide the same cooling
  5. You spend more to cool your home

If you’re lucky, increased energy costs is the only problem you’ll have from an AC with a dirty condenser coil. Many homeowners who don’t clean their coils also experience problems like:

An air conditioner that keeps tripping your breaker
Since the air conditioner has to work harder and longer to cool your home, it can overheat and trip the breaker.

Warm air coming out of your air vents 
A dirty condenser coil struggles to get rid of the heat in the refrigerant, which means less heat is pulled from your home’s air, resulting in warmer air coming from your vents.

Blown compressor
The compressor is the pump that moves the refrigerant. It’s the heart of your air conditioner. The SEC study found that a dirty condenser coil caused the compressor to lose up to 70% of its power. That means it's working harder and, if left like that, will likely break down sooner.

And compressor’s aren’t cheap. If if breaks and isn’t covered under warranty, you should probably think about replacing the whole unit.

Luckily, though, the solution to all these problems is simple: clean your outside AC unit’s coil.

How to clean your air conditioner’s outdoor unit

We’re going to show you how to do this. But to be 100% honest, we usually recommend that a professional AC tech takes care of this maintenance for you because:

  • You can damage the small fins on the coil
  • You can also flood the AC fan with water and kill it 
  • Pros have a special coil cleaning chemical that will clean even better than water alone

But, if after all of that, you still want to tackle it yourself, we want to make sure you’re doing it right. So here’s how to do it.

Note: Cleaning the coil is included as part of our yearly maintenance visit. So if you have a planned maintenance agreement with us, we do this for you already!

1. Find your air conditioner’s outdoor unit and shut off the power to it. You can do this at the disconnect located right next to the AC unit.

An abstract image

The AC disconnect box. Open this and pull the fuse or flip the breaker.

2. Brush off any leaves, branches and/or weeds that are in or on the outside unit.

A cute kitten

Get the leaves out of the grill

3. Remove the outer cover. This varies from model to model, but usually consist of removing a few sheet metal screws and then the cover just comes off. (Don’t lose the screws!)

4. Starting at the top and working your way down, spray the coils from the inside out with a hose. This will help wash the debris out of the AC unit.

Caution: Do not use a powerwasher or high-pressure hose attachment as the high water pressure can bend and damage the delicate fins on the coil.

5. Go over the coil again, spraying at a different angle until the water leaving the coil is clear.

6. Replace the AC cover and turn the power back on.

Get a pro to take care of all your AC maintenance

This is only part of the regular maintenance an air conditioner needs. An annual maintenance plan takes care of the condenser coil cleaning as well as the evaporator coil cleaning and AC check-up that manufacturers recommend.

Contact Santa Fe Air and have us take care of your air conditioning maintenance today.

Santa Fe Air Conditioning and Heating serves the Kansas City area. For more information, contact us online