What Makes An Air Conditioner Freeze?


What Makes an Air Conditioner Freeze?

In North Carolina, June thru August make for the worst possible times to endure a frozen home air conditioning system. It means that:

  • The AC blows hot air if any air at all
  • Perspiration becomes hard-boiled sweat
  • Your comfortable leather lounge chair takes on the feel of heated tarpaper against your bare back
  • T-shirts cling like wet flypaper
  • Free-standing fans merely circulate the heat
  • AND Your normally meek and loving family becomes an aggressive force for rapid household repairs.

In this article, the HVAC techs at Delta Heating & Cooling point out some of the things that can make your Raleigh home air conditioner freeze. But knowing the why is not so as important as knowing how to correct the why, so we also offer some tips on how to repair a frozen AC.

Raleigh Home AC Care – Frozen AC Defined

Window unit or central AC system, a freeze up occurs when layered ice forms on the outside of the unit. Cause and effects don’t change. However, central air conditioning systems can also freeze up when ice forms on the condenser coils within the air handling system. Even though the outside evaporator coils do not reflect evidence of a freeze up, a reduction in internal air distribution may suggest an AC freeze up within the air handler. In either event, a frozen air conditioning system puts stress on your HVAC components. If left unresolved, you may encounter costly repair or even the need to replace your condensing unit compressor.

Air Conditioner Freeze Causes and Solutions

1. Obstructed Air Flow

  • A dirty air filter – Fix by cleaning or replacing the filter
  • Closed or blocked air vents – Repair by opening the vent or removing the obstruction
  • Dirt on the evaporator coils – Disconnect electrics. Use water pressure to clean
  • Dirt on coils in air handler – Cleaning is the answer, but this service is better left to your Raleigh Delta Heating & Cooling HVAC professional
  • Damaged ductwork – May cause excessive running time on the AC. This too is an Air Conditioning repair problem best left to pros.

2. Excessive Outdoor Temperatures

In Raleigh, the average summer temperature peaks in mid July at 89.1 degrees Fahrenheit. But if you don’t find that sufficient stifling, consider that on any given day the average NC temperature can easily be topped. The hottest day in recorded North Carolina history came in at 110 degrees back in 1983, this according to WRAL Weathercenter.

The hotter the outside, the harder your Raleigh home air-conditioning system must work. The harder the system must work, the greater the possibility of a freeze up. When dealing with extensive external temperatures:

  • Clean the filter more often than normal
  • Ensure that the thermostat setting remains no lower than 74 degrees.

3. Loss of Refrigerant Coolant

If properly sealed, your Raleigh home AC system should not loose coolant. However, leaks do develop, and low coolant can cause a drop in evaporator coil pressure. Moisture invades the system. Your air conditioning unit undergoes system freeze up.

Solution to low refrigerant coolant:
Contact Delta Heating & Cooling. Our certified HVAC techs will examine your AC, find and repair the leak, and then balance your refrigerant to factory specs. Click here for more information on our Raleigh, NC residential heating and air conditioning sales, installation and maintenance services.