How Your Dog Can Destroy Your Air Conditioner (And How to Protect It) - Coolray Atlanta

Dogs are notorious for destroying your lawn and digging holes. But they can also do this to your air conditioner. For example:

Air conditioner damaged by dog urinating on it. Source: cspi2002 on YouTube

A dog (or multiple) decided to mark this air conditioner. And, as you can see, dog urine is quite corrosive.

If you have a newer AC, it likely has a heavy-duty protective grates. But even that won’t protect your AC from dog urine. It just hides it. Check out the AC below that was found by a home inspector.

Dog urine destroyed the coil under this AC’s grate. Photo source: Inspectopia

Damage like this can be expensive. Depending on the amount of deterioration, you have 3 possible outcomes:

  • You can leave it, but your efficiency will suffer
  • You’ll have to replace the condensing coil
  • You’ll have to replace the whole outdoor unit

Below, we’ll explain each of these outcomes in more detail and give some advice on when to choose each option. But first, you need to understand what it is that your outside unit even does.

What your outside AC unit does

The outside air conditioning unit’s primary job is to get rid of the heat your AC collected from inside your home. Here’s how it works:

  1. Hot refrigerant flows through a copper tube (called the condensing coil).
  2. A fan blows air over the coil.
  3. The air absorbs heat from the coil, cooling the refrigerant.
  4. The compressor pumps the cool refrigerant back into your indoor unit to absorb more heat
  5. Repeat.

Related: How an Air Conditioner Works

Diagram of an outside AC unit from Inspectapedia.

Now, attached to the condensing coil are aluminum fins (that’s the grey part you see in the photo below). These fins help improve the AC’s energy efficiency by increasing the surface area of the coil. Increased surface area helps the coil dump the heat faster.

Damaged outdoor AC unit showing fins. Original image source: cspi2002 on YouTube

Now, let’s look at the different possible outcomes from dog urine damage on this outdoor unit.

Leave it and suffer decreased energy efficiency

If only a small area of aluminum fins (less than 25%) are damaged and the coil is not leaking, you may choose to just leave your AC alone for now.

While the fins are important (they increase energy efficiency), missing some of them doesn't make the air conditioner inoperable.

So long as you do something to keep your dog from making the damage worse, your AC should continue to work fine. Of course, you will have higher AC bills. But they will likely be less than the cost of a new coil or unit.

Cost of damage: 2-10% decrease in energy efficiency

But if there’s damage to the coil itself, you may need to...

Replace condensing coil

The condensing coil is the metal tube you’re seeing when the fins have disintegrated.

Damaged AC showing condensing coil. Original image source: cspi2002 on YouTube

As we mentioned before, the condensing coil’s job is to get rid of the heat your air conditioner absorbed from inside your home.

You should replace the coil when dog urine has caused extensive damage to the coil or more than 25% of the fins are missing AND:

  • Your air conditioner is still relatively new.
  • A replacement coil can be found and installed for no more than 50% of what it’d cost to replace the whole outside unit.

Cost of damage: $600 to $2,000+ to replace coil

But sometimes you have to...

Replace entire outdoor AC unit

Replacing the whole outside unit is usually the best option when the coil needs to be replaced and at least one of the following is also true:

  • The air conditioner is old (10+ years) and near replacement age anyway
  • Replacing just the coil will cost more than 50% of replacing the whole outdoor unit
  • There’s no replacement coil available

Cost of damage: $1,500 to $3,000 to replace outdoor unit

How to keep your dog away from your AC

As you can see, dog urine can cost you hundreds—or even thousands—of dollars. Luckily, the solution is easy: keep your dog away from your air conditioner by installing a fence around it.

Caution: Most air conditioner fences are installed incorrectly. If the fence blocks airflow to the air conditioner, your air conditioner will work less efficiently. For that reason, we recommend that your fence be:

  • At least 3 feet from the air conditioner
  • Not solid, so air can flow through it

Here’s a good example we found at Lowe’s:

No Dig Powder-Coated Steel Decorative Metal Fence Panel from Lowe’s

Further reading:

Coolray is your Atlanta-area home comfort expert with specialists in heating, air conditioning, air quality and plumbing. Have more questions? We’d be happy to help – just contact us online.

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