Condenser Coil cleaning in air conditioners?

Air Conditioning works by exchanging heat from inside a building to the outside air. To do this some very basic refrigeration principles need to take place. One of the most critical pieces that make this happen is the condenser coil. This is usually the aluminum coil the surrounds the air conditioning compressor.
What happens inside this outdoor unit is a very basic state change of the refrigerant inside the air conditioning unit. The refrigerant that changes from a liquid to a gas inside the indoor coil moves to the outside where the compressor compresses the gas under high pressure. When this happens the gas also becomes very hot. The hot gas then leaves the compressor to start traveling through the many feet of tubing in the condenser coil. As the gas cools it changes back to a liquid form going back indoors to start the cycle all over again.
Big problems start when the condenser coil becomes so blocked up with dirt that the hot gas in the condenser coil does not cool enough to change the hot gas back to a liquid form. If this happens the cooling process does not happen and then air conditioner runs but is not cooling. The compressor starts to get very hot and the ultimate result will be the death of a compressor. For these reasons the condenser coil must be kept clean and free of debris at all times when the air conditioner is running. Cleaning the coil is a fairly simple process, Here are a few guidelines to follow when doing this.
To clean the coil a few simple tools are needed. A garden hose with a nozzle, wrenches to remove the condenser fan, a garden sprayer for applying the cleaning solution. The first thing is to disconnect the power to the outdoor unit. There should be a disconnect switch of some type near the condenser. Then remove the fan from the condenser unit. Usually this will be the top of the unit. The fan can usually be laid aside carefully without disconnecting the wires to the motor. Carefully wet down the coil with the garden hose. If you have very high pressure water where you live be careful that the water pressure does not bend over the fins on the coil. These are very thin and fragile. If they get bent over the air will not be able to freely flow through them. Using the cleaning solution from the garden sprayer, coat he inside and the outside of the coil. Let the solution work on the dirt build up before washing it off. If you use a foaming type coil cleaner then let the foam cook the dirt out of the coil. Then use the garden hose to wash the dirt out of the coil. I often work from the inside spraying out through the coil. This is the reverse of the usual air flow and it washes the dirt out easier. Rinse the coil with water till it is clean with no more dirt or cleaner coming out. Replace the fan and start the unit back up.
The cleaning solution for the condenser coil can be any good household cleaner. Many automotive type radiator cleaners will work well. For very dirty condensers it would be good to buy a foaming coil cleaner made specifically for cleaning condenser coils. A local plumbing and heating supply house should stock coil cleaning solutions. Most of these solutions are very strong chemicals. Be sure to wear gloves and eye protection when working with them.
By keeping your air conditioning condenser coil clean, you will help to have your air conditioner running at the best efficiency possible. A clean condenser coil is one of the easiest ways to save electric while running your central air conditioning system. A clean coil will allow your compressor to run cooler and help it to last longer. Your condenser coil should be thoroughly cleaned at least once a year. If in you live in very dirty areas like along a dirt road you may need to clean the condenser coil more often. Also do not do things that would clog up the coil. Blowing grass clippings into the condenser coil is one common thing that happens. Keep shrubbery from growing into and around the condenser coil. This stops the air flow to the coil. Large flowers planted too close to the coil can do the same thing.
As you can see there are many things that can cause your air conditioner to work harder and cost you more money. By taking a the time to look over things and give it a cleaning you can save a lot of money.

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The outdoor condenser coil of your air conditioner performs a tough job in warm weather. It takes the concentrated heat collected from your home and dumps it into the hot outdoor air. To get rid of the collected heat, your outdoor condenser coil has to move a lot of air. If the coil is dirty or if plants or other objects are too close to the conditioner unit, the fan in the outdoor coil can't move as much air as required for good performance and efficiency. This raises your electricity cost for air conditioning and may shorten the life of the outdoor condensing unit.

Your condenser coil should never have the visible buildup of dirt you see here.

Around the outdoor condensing unit of the air conditioner, remove plants and other debris from within 3 feet of the unit in all directions. Make sure the air's upward path in leaving the unit is unrestricted for at least 5 feet. If your outdoor unit is installed under a deck or if someone built a trellis or some other structure above it, either move that structure or hire an air-conditioning contractor to move the outdoor unit.

Most condenser coils are loaded with pollen and dust even when you can't see it. The longest a condenser should go without cleaning is 2 years, depending on how much it operates during the summer. If your cooling season is 4 months or more, annual cleaning is an excellent idea. Turn off the power to the unit, and remove any visible grass and lint from the fins and/or louvers with an old hairbrush or whisk broom. Then put on a pair of rubber gloves and spray biodegradable outdoor coil cleaner into the coil. Wait five or ten minutes and flush the coil with a gentle water spray.

If the aluminum fins on the outside of your outdoor coil have dirt, leaves, or lint stuck to them, it's time to clean the coil. If the coil is very dirty, it’s better to have a professional clean it. Before doing any cleaning work, shut the unit off at its main switch outside near the unit.

An old hairbrush works well for brushing surface dirt and lint off the fins. Brush in the same direction as the slots between the fins so the bristles go between the fins. You can do a better job if you remove the guard grill, which protects the coil. Wear a dust mask to avoid breathing the dust. When you've finished brushing out as much of the dirt as you can, spray a heavy-duty household cleanser into the coils. Let the cleanser sit for five minutes. Then, direct a light spray from a garden hose at the coil's interior through the fan opening in the top of the unit. Use a gentle spray because a strong spray could bend the aluminum fins.

Remove the surface dirt with an old hairbrush before spraying the coil with coil cleaner and rinsing it with a gentle spray of water.