One of the most frustrating problems with a window air conditioning equipment is if it starts to ice up. For the owner of the air conditioner is could be perplexing.

When this problem occurs a lot of people immediately think it is the fault of the refrigerant gas. More regularly the cause is the result of other difficulties.

It is most often the result of poor airflow.

Any time the airflow via an air conditioner is fixed the coolant system becomes affected. If taken up to extremes the critical pressure-temperature balance of the cooling coil can be changed. If they drop too low the cooling coils surface temperature can drop below the dew point temperature of the room. When this happens the cooling coil will quickly operate as a refrigerator instead of an air conditioner. Rather than simply cooling the air it will collect and hold moisture. The moisture will freeze onto the cooling coil where it’ll appear as ice 坐地冷氣機.

The principal job of an air conditioner would be to de-humidify, not refrigerate, the room air. By removing the moisture from the room air it gives us a feeling of comfort. To get this done though the temperature of the cooling coil must always be higher than the room’s dew point. If it’s allowed to drop below the dew point the air conditioning equipment will start to produce ice.

With this information in mind the following are several problems that can result in your air conditioner icing up:

1. Dirty filter.
To avoid this replace or clean your filter every little while of the cooling season. In case a smoker do it weekly. To clean filter remove from air conditioning equipment, wet thoroughly, and lay in bottom of a sink. Sprinkle detergent (laundry detergent is effective) onto filter surface. Allow to sit for a few minutes. Add tepid to warm water to sink so that filter is completely covered. Soak for a quarter-hour. Remove from water and rinse. Allow to air dry.

2. Dirty or blocked cooling coil.
An air conditioning equipment requires regular maintenance. Usually every two or three years. Every year will be best, but this can be costly unless you do it yourself. During cleaning the cooling coil ought to be degreased and washed to eliminate accumulated dirt and debris. Degreasing is important to eliminate any coatings on the coil. If not done greasy residue can trap and hold air borne particles. They will build-up on the coil and affect heat transfer. If left too long this can result in the cooling coil becoming partially blocked . This can produce a lower airflow.

3. Dirty or blocked condenser coil.
The condenser coil may be the one at the rear of the air conditioning equipment. Its job is to dissipate the heat that is being removed from the area. Similar to the cooling coil it too must be cleaned every few years. Since the condenser is externally of the house it becomes exposed to plenty of dirt, pollen, and smog. Since airflow direction is from inside to outside it is the inside surface of the condenser that becomes dirty. Therefore to completely clean this part the air conditioning equipment must be completely disassembled. Or even cleaned regularly an airflow blockage here can even burn up the compressor. Before this happens though the lowering of airflow will affect the entire operation. This can bring about the compressor efficiency dropping, the inner pressure-temperature relationships being affected, and the resultant production of ice on the cooling coil.

4. Inefficient compressor.
As describe above an inefficient compressor could cause icing up. If the compressor struggles to pump the refrigerant properly the cooing coil may not get cold enough to shut down the cold control. It can hover just above the take off point. When this happens the cooling coil will begin to refrigerate. Ice on the cooling coil will result. If the compressor itself is at fault the air conditioner will have to be replaced. But remember that many icing problems are misdiagnosed as bad compressors when they were actually one of the other faults discussed in this article.

5. Not enough refrigerant. An excessive amount of refrigerant.
Both scenarios can lead to and icing condition. If your air conditioner was repaired recently suspect an excessive amount of refrigerant. Blended with an airflow problem this is often difficult to diagnose. If not repaired recently then suspect airflow problems before considering a refrigerant imbalance.

6. Outdoor temperature too low.
Icing can occur if the outside temperature falls below 60 Degrees Fahrenheit. If the outside temperature is too low the air conditioner pressure-temperatures can be affected. When the outside temperature falls the cooling coil temperature will also fall. So much that the coil will refrigerate the area air. This will result in the cooling coil beginning to produce ice. This issue is more prevalent in the fall. If it is hot throughout the day but cold during the night suspect this problem as the cause of icing up. If this problem is suspected try running the air conditioning equipment in the fan only position. Leave the re-circulating vent open. This will circulate the area air without cooling it, while attracting handful of outside air during the night.