Home Improvement Tips & Advice Provided by the Home Service Doctors

My Air Conditioner Keeps Freezing: Here's Why It Happens

Your air conditioner is in charge of keeping you happy, cool, and comfortable in the hot days of summer. Although, sometimes things can get out of hand and it can get too cool. In fact, it is possible that your air conditioner can freeze or ice over.

AC units work by utilizing a physics fundamental – the Joule-Thomson Effect in particular – that states expanding gas loses temperature, or energy. The AC coil in your system is the component of the system that helps regulate the expansion of the air flowing through the system. If a part is defective in the system, though, it could overwork the coil, causing it to eventually freeze.

Here are a few reasons that can trigger an AC coil to freeze:

  • A weak flow of air through the evaporator coil imbalances the heat exchange.
  • Low refrigerant levels drop the total pressure of the system, which further cools the air inside it due to the Joule-Thomson Effect.
  • You are trying to drop the temperature to or below 60 degrees, give or take a few degrees. Overworking an AC unit to such a low room temperature is likely to freeze it.
  • A break in the AC system can cause the refrigerant line to malfunction, an internal fan to short circuit, and so on. There are so many moving parts and electrical components in an AC system. If just one glitches, then the consequences can be varied and many, including freezing or icing.

How to Fix a Frozen Air Conditioner

There are a few solutions you can try on your own to fix an iced AC:

  • Change the air filter
  • Clean accessible air ducts and ports
  • Check the evaporator coil, if possible

Most of the time, though, an AC unit that repeatedly freezes up is indicative of a system that needs maintenance or repairs from a service professional. Otherwise, any fix you make will probably just be temporary, and the overall problem will just get worse.

Home Service Doctors in Fairfax offers AC de-freezing and repair services at competitive prices. Be sure to call us at (703) 997-1660 if you live in the Fairfax area and need HVAC help.