Why is My Air Conditioning Freezing Up?

Good Deals Heating and Cooking air conditioning repairFreezing up or icing up of air conditioners is a frequently encountered problem. Irrespective of the fact, whether the unit is a window AC or central AC, the reasons and the solutions are similar.  One cannot ignore freezing up in an air conditioner. It gives rise to two problems: inefficient cooling and potential damage if not corrected.  The key is to know when to call for air conditioning repair.

To understand why an air conditioner is freezing up a thermodynamics principal needs to be understood. The Joule-Thomson effect states, that when a gas expands, its pressure as well as temperature decreases. This result happens when all the other parameters are kept constant. Similarly, when a gas is compressed, the temperature increases. In other words, molecules of the air feel hot when they are moving rapidly and when they move slowly, the air feels cold.

On this basis, the evaporator coil in an AC expands the refrigerant. This expansion causes the coil to cool. The cold coil then mixes with the air at room temperature, and the coolant absorbs the heat. The now heated refrigerant is then thrown out of the house by compressing it, which heats it up and transfers it outside. The cycle gets repeated many times, and the room gets cold. When there is a problem, the air conditioner’s evaporator coil gets much colder than it should, thus freezing up the AC. This freezing up happens due to several reasons:

No Enough Airflow Across the Evaporator Coil: ACs are meant to bring down the temperature by drawing away the heat. If the AC is not blowing the internal air correctly over the coil, the exchange of heat does not take place. Over time, the coil temperature will drop, and the AC freezes up.

Low Refrigerant: When the amount of refrigerant (freon) in the system is low, it still expands to the same amount. As stated above when gas expands, the temperature drops. As the temperature of the coil drops below the freezing point, the moisture in the air freezes when it contacts the coil, thus icing it up.

Mechanical Problems: If an air conditioning repair is required then the pressure change in the system leads to freezing up. The problem may include an obstacle in the refrigerant, a non-working blower, or a blocked filter.

High Outside Temperatures: When the outside air temperature is extremely high, and the AC is continuously running, the system pressure inside the unit will drop and cause freezing up.

For an air conditioner freezing up on a consistent basis, call for air conditioning repair to get to the root of the problem. For assistance in the Philadelphia area, contact Good Deals Heating and Cooling at 215-947-1166.