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

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

It is most often the consequence of poor airflow.

Any time the airflow through an air conditioner is restricted 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 begin to operate as a refrigerator instead of an air conditioner. Instead of simply cooling the air it will collect and hold moisture. The moisture will freeze onto the cooling coil where it’ll appear as ice.

The principal job of an air conditioning equipment would be to de-humidify, not refrigerate, the room air. By detatching the moisture from the room air it gives us a sense 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 begin to produce ice.

With this information at heart the following are several problems that can lead to your air conditioner icing up:

1. Dirty filter.
To avoid this replace or clean your filter every couple of weeks of the cooling season. In case a smoker do it every week. To completely clean filter remove from air conditioning equipment, wet thoroughly, and lay in bottom of a sink. Sprinkle detergent (laundry detergent works well) onto filter surface. Allow to sit for a couple of minutes. Add tepid to warm water to sink in order that filter is totally covered. Soak for 15 minutes. Remove from water and rinse. Allow to air dry.

2. Dirty or blocked cooling coil.
An air conditioner requires regular maintenance. Usually every several years. Every year will be best, but this could 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 essential to eliminate any coatings on the coil. Or even 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 will produce a lower airflow.

3. Dirty or blocked condenser coil.
The condenser coil may be the one guiding the air conditioner. Its job would be to dissipate the heat that is being removed from the room. Similar to the cooling coil it too must be cleaned every few years. Since the condenser is on the outside of the home it becomes exposed to a great deal of dirt, pollen, and smog. Since airflow direction is from inside to outside it’s the inside surface of the condenser that becomes dirty. Therefore to completely clean this part the air conditioner must be completely disassembled. Or even cleaned regularly an airflow blockage here may also burn out the compressor. Before this happens though the lowering of airflow will affect the overall operation. This can result in 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 might not get cold enough to shut off the cold control. It could hover just above the cut off point. At these times 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 on this page.

5. Not enough refrigerant. An excessive amount of refrigerant.
Both scenarios can lead to and icing condition. If your air conditioning equipment was repaired recently suspect too much refrigerant. Mixed with an airflow problem this can be difficult to diagnose. Or even repaired recently then suspect airflow problems before considering a refrigerant imbalance.

6. Outdoor temperature too low.
Icing can occur if the exterior temperature falls below 60 Degrees Fahrenheit. If the outside temperature is too low the air conditioning equipment pressure-temperatures can be affected. When the outside temperature falls the cooling coil temperature may also fall. So much that the coil will refrigerate the room air. This will result in the cooling coil beginning to produce ice. This problem is more frequent in the fall. If it’s hot throughout the day but cold during the night suspect this problem as the cause of icing up. If 坐地冷氣機 is suspected try running the air conditioner in the fan only position. Leave the re-circulating vent open. This will circulate the room air without cooling it, while bringing in a small amount of outside air at night time.