How To Remove Dog Urine From Air Conditioner Coils

If you live with a dog, you probably know that you need to pay attention to certain canine activities so your dog stays out of trouble and doesn't damage something that's costly to fix. If he's marked your AC unit, for example, and you have to remove dog urine from the air conditioner coil, you'll need to approach the project quickly and carefully and take steps to prevent it from happening again.

The coil on the air conditioner unit is critical to its function. The AC system circulates a refrigerant that is heated and cooled with each cycle. The refrigerant draws heat from the house and, in the outdoor unit, passes through the coil, an assembly of winding copper tubing surrounded by thin metal fins. The fins disperse heat from the tubing to quickly cool the refrigerant inside the tubing. At the same time, a fan pulls outdoor air through the fins to facilitate cooling. The cooled refrigerant then re-enters the home for the next stage of the cycle.

Believe it or not, dog urine is corrosive to certain metals, including aluminum and copper. Unfortunately, most air conditioner coils are made from copper tubing, and the fins attached to the coil are usually made of aluminum. This means that a dog simply intending to mark its territory can cause extensive corrosion to the coil with enough time and enough urine.

At first, corrosion will start on the aluminum fins. The unit will still be able to operate, but efficiency will take a hit, meaning the air conditioner will need more energy to produce cooling at the same rate. Your electric bill may start to go up. Eventually, corrosion will eat away at the fins and reveal the copper tubing underneath. If the copper coil corrodes, refrigerant could leak from the system.

A large leak can have an environmental impact as well as repair or replacement of the coil itself. If a large enough portion of the coil is damaged, it may need replacements. Depending on your model, it may be more cost effective to replace the entire compressor/condenser unit at that point.

If you catch the problem early enough (for example, if you catch the canine in the act), you can probably clean off most of the urine before it starts to eat away at anything. First, turn off the power to the air conditioning unit, using the outdoor AC disconnect switch or the circuit breaker in your home's breaker box. You don't want to have any power going to the unit during cleaning.

Next, remove any protective grills and hose them down with a light spray from a garden hose. You should be able to see visible evidence if there's urine buildup on the grates. Gently spray the air conditioner coil in the area of the accident. You can clean the internal or external fins of the air conditioner with an air conditioner fin cleaning brush, a tool designed for this part specifically. Take time to clean out other debris that may be stuck in the coils, like leaves or pollen. Let the air conditioner dry for one hour before restoring power to the unit.

Better than having to clean your air conditioner unit at all is to keep your dog from visiting it to do its business in the first place. You can create a barrier around the unit (providing at least 3 feet of space for ventilation) using a fence or wire mesh. Make sure the barrier allows for plenty of airflow for the unit. You can also supervise your dog while it plays outdoors and ensure it doesn't go near the air conditioner, but a barrier is probably a more foolproof option.