Hansberger Refrigeration Blog: Your AC Repair Resource

Why Is It That You Find Your AC Unit Freezing Up in Summer?

Though your air conditioner is designed to provide ample coolness, an AC unit freezing up in summer is a symptom of malfunction in the system. Air conditioners are actually heat movers. Coolness is simply the natural result after heat extracted inside the house is moved outdoors. This process relies on refrigerant circulating through coils that absorb heat inside the home and release heat outside. However, certain issues may cause temperatures inside the system to drop too low, triggering ice formation in the indoor evaporator coil.

Consequences of an AC unit freezing up in summer include:

  • Declining cooling performance.
  • Longer cooling cycles and higher operating costs.
  • Damage to critical components, including the system compressor.
  • Total system shutdown and loss of cooling in hot weather.

Why Is Your AC Unit Freezing Up in Summer?

Low Airflow

If system airflow drops below specifications, the evaporator coil temperature may drop too low. Condensation forming on the coil then turns to ice that slowly strangles airflow through the coil passages. A frozen air conditioner may initially run nonstop — causing severe damage to components like the compressor — then eventually shut down entirely.

The most common cause of low system airflow and an AC unit freezing up in summer is a dirty or clogged air filter. During the summer cooling season, the air filter should be replaced monthly with a quality pleated cotton or polyester filter with a MERV (Minimum Efficiency Reporting Value) rating around 8.

Refrigerant Leaks

If the volume of circulating refrigerant drops below specifications, the refrigerant cannot extract sufficient heat, and it becomes overly frigid. Ice crystals form on the coil, eventually accumulating into a thick layer, culminating in an AC unit freezing up in summer. Since leaks are the usual cause of low refrigerant, simply adding more refrigerant is not a viable solution. Professional service to detect and repair these tiny leaks, then restore proper refrigerant levels, is required.

An AC unit freezing up in summer jeopardizes indoor comfort as well as vital system components. Contact the professionals at Hansberger Refrigeration and Electric Company for qualified, experienced service.