An interesting thing about Arizona HVAC is the weird connection between high daytime temperatures and frozen air conditioners. If you find your air conditioner frozen, you will notice frost on the coils but little or no cool air in your home. It is a frustrating problem, but one Phoenix HVAC contractors see every day.

Do this first: Switch your cooling system to fan or “on” and let the system run on this setting until the ice melts and the system unfreezes. Please note that this is not a permanent solution; it will prevent further damage being caused to your HVAC unit.

An Air Conditioner Freezing During Summer is Real Science

A central air conditioner is a marvel of technology that taps the power of science. Refrigerant in your AC lines in intentionally compressed (by a compressor) and then allowed to expand.

Liquid refrigerant confined under pressure, then allowed to expand under low pressure in an evaporator, cools. This is the Joule-Thomson Effect; it allows your central air conditioner to chill your Phoenix home’s air efficiently and repeatedly with the same refrigerant.

The laws of thermodynamics mean the cooling refrigerant cools your home’s air by absorbing heat from that air. The warmed refrigerant is pumped outside, where the heat is released, and the cycle continues.

Frozen Coils

Howard Air - Causes of Frozen A/C Coils During Summer Time Infographic

Seeing frozen coils on air conditioner parts, either inside or outside your home, is a little unsettling in summer, especially in the desert. The indoor evaporator coils could freeze up if too little home air is blowing across them.

Other causes for frozen coils on air conditioner components:

  1. Too little refrigerant, which implies a dangerous leak in a line; this requires professional servicing quickly.
  2. Running the AC when outdoor temperatures (at night, for example) are low.
  3. Blower fan problems.
  4. Kinked refrigerant line preventing smooth flow of the liquid.
  5. Clogged air filters that impede air flow.

Solving Your Frozen Coils

Because one cause of frozen coils in an air conditioner could be a refrigerant leak, you should contact your HVAC contractor for a service call. The trained technician will diagnose the cause of the freezing and then repair air conditioner parts as needed.

Refrigerant cannot legally be released into the atmosphere because of its role in harming our environment. A trained technician can find and fix any leak, and then provide the right amount of refrigerant. This is usually between two and four pounds per ton of cooling, which translates to six to 12 pounds for a typical Phoenix area home.

Howard Air

For frozen coils and all your air conditioning needs, please contact us today. We will be happy to inspect and diagnose your entire system.