If your air conditioner does not seem to be working as well as it should, your natural first reaction is to go out and take a look at the compressor to see if there is anything you can do quickly to correct the problem. Of course, you cannot assess the situation unless you know what you are looking for. For instance, if you see ice forming on the condenser coil or anywhere else on the air conditioning system, you will know you found the likely source of the problem.
Ice can form in your air conditioner for a number of reasons. The most common one is that your refrigerant levels are low. Since this refrigerant is contained in a closed system, a deficiency in refrigerant means that there must be a leak somewhere in that system. Only a certified professional can refill your refrigerant and determine where the leaks are in the system to make the necessary repairs.
Another reason that ice can develop in your air conditioner is because the air is not flowing fast enough through the system and across the coils. This can happen because of a problem with the fan or because there is an actual physical impediment to the air flow. Regardless of the reason, the ice will form because without adequate air flow the condenser coils will get too cold.
These coils are typically kept just above freezing by the constant flow of air across them. When the air passes by them at this temperature, the moisture from the air condenses on the surface of the coil. But because the coil is not quite freezing, the water then runs down into a collection pan. When the coil is too cold, however, the moisture from the air will freeze on the coil before it can run off.
This ice actually manages to insulate the coil and keeps it from properly cooling the air or removing any additional moisture. If left unattended, the ice in your central air conditioning system can cause real damage to the unit. Plus, it is not allowing the air conditioner to do its job and cool your house down. So if you notice any amount of ice at all beginning to form on any part of your air conditioner, be sure to call for professional service right away.