The air-conditioning unit is supposed to blow cool, refreshing air throughout your home, right? You can pretty much spot it right away if there is problem with the unit. Blowing warm air or the presence of a funky smell are noticeable indicators of a problem. But what if you don’t notice the problem occurring? To you and your family, it may seem as though you have a perfectly functioning AC unit, but if you take a closer look and find layers of ice or frost inside the unit, you have a problem that needs attending.

Whether your AC unit has a few ice chips here and there or it looks as though winter came over night, it’s time you have this checked out. It may not be noticeable or even as thick at first, but even the slightest indication of freezing should prompt immediate attention. When not taken care of, you are putting you and your family’s health at risk. The unit will eventually leak or break, emitting a foul smell throughout your home. Before it becomes noticeable, call your professional HVAC contractor today.

The Joule-Thomson Effect

While you may not feel this is an important element to know, this explanation will make more sense when you are dealing with a freezing AC unit. The Joule-Thompson Effect is the principle of thermodynamics. This means that when everything is kept constant, gas expands as the pressure decreases, and the temperature also decreases. When the air molecules are moving rapidly, you will have a warmer temperature. But if the molecules are moving slowly, the air will be cold. This is crucial to the understanding of how your AC works. Because your system works by allowing the coil to expand the refrigerant inside of it, you will experience cooler air as the refrigerant absorbs the heat from your home.


Your AC uses compression and expansion to heat and cool your air. Freon and coolant can spring a leak within your AC unit and cause automatic freezing in the refrigerant.


Did you know that your AC is made to function in a specific temperature range? If the air outside is lower than 64 degrees and you have your AC on, your unit will freeze due to the pressure inside of the system.

Mechanical Failures

You may not know that your system has a kink or two if you don’t regularly check or clean it. If you are noticing a change in the pressure within the unit, this could be due to a faulty blower fan, clogged filter dryer, or breakage in the refrigerant line.

Insufficient Airflow

You may experience a drop in temperature within your home. This is due to the fact that inside air isn’t blowing over the evaporator coil removing the heat from your home.

Low Refrigerant

Lower than usual pressure in the system will make your AC unit freeze. Again, set your AC to an appropriate temperature based on the outside air.

So, how do you fix this freezing problem? Call a professional to handle this delicate and tedious job. You may feel that watching your YouTube videos has paid off, but you may not be ready to handle a job that entails much in-depth mechanical detail. The Air Experts can walk you through their procedure and offer sound advice on your faulty and freezing system. Call for more information today!