With a frozen air conditioner, you have an airflow blockage. When air cannot flow freely over the evaporator coils and through the fins, they freeze, and the unit stops working. Consequently, according to Ask This Old House’s video, How to Repair a Frozen Air Conditioner, check the air filter first and replace it if necessary. Otherwise, check for other issues: supply ducts in disrepair, refrigerant leaks, or mismatched evaporator coils and condensers.
Ideally, says air conditioner repair expert Richard Trethewey, the condenser provides one ton of cooling for every 500 to 600 square feet of indoor space on the hottest day of the year. Tons refers to the cooling provided by one ton of ice.
The condenser dumps heat and returns cool air after passing through the evaporator coil again.
Size matters, but oversized condensers do not provide better cooling. When the condenser is too large, it freezes the evaporator coils, blocking airflow. Matching the condenser and evaporator to the house size often solves that problem.
Contact your local air conditioner repair expert if you see ice or other signs of a frozen AC. Let them troubleshoot your unit and keep your home cool.