A frozen air conditioner isn’t only frustrating on a hot summer day—it can be damaging to the unit. But why does it happen, and what steps should you take if it does? There are a few simple solutions to do the trick.

3 Main Parts of Your Air Conditioner 

At the most basic level, the three main parts of your air conditioner include the evaporator coil, compression coil, and refrigerant. Refrigerants are compounds that absorb heat and easily change from gaseous to liquid forms—the process of changing from one state to another causes heat or coolness (evaporation causes coolness while condensation causes heat) which is essential for your air conditioner to work.

The refrigerant enters your evaporation coil and cools it. Hot air from your home blows on this coil and is absorbed by the refrigerant, which then returns to its liquid form. The heat during this change is pushed outside, leaving your home with only cool air.

Reasons Your Air Conditioner Freezes

Your air conditioner freezes up when something is wrong with one of these parts, causing the heating and cooling process to be thrown off-balance. Check your air conditioner’s filter. It should be cleaned or replaced every two to three months because a dirty filter stops the air that usually blows onto the evaporation coil.

When the refrigerant has no hot air to absorb, it stays cold and drops the temperature of the coil to below freezing. Humidity in the air builds up on the coil and freezes there, causing ice to form. If your filter is fine, check your evaporation coil—if it’s dirty, this can also prevent the hot air from reaching the refrigerant.

Another reason your air conditioner might freeze up is if you’re running low on refrigerant in the system. The refrigerant cools as it expands, and if there’s less refrigerant expanding into the same amount of space as before, it will expand further and cool more, causing the evaporation coil to freeze. Since the same refrigerant is used over again in the cycle of evaporating and condensing, a lack of refrigerant means there’s a leak somewhere. Have a professional inspect and fix the source of the leak to make sure it doesn’t continue.

Luckily, insufficient airflow is one of the most common causes of a freezing air conditioner, so it should be an easy fix. However, if your filter and coil are both squeaky clean, it’s time to call a professional to make sure your air conditioner is fixed before the frost damages it. 

If you need help with air conditioner repair, call the HVAC experts at Duncklee Cooling & Heating Inc in southeastern Connecticut and western Rhode Island. With 44 years of experience, they offer fast, efficient service, so you can stay cool all summer. For questions about repairs, or to schedule preventative maintenance, call Duncklee Cooling & Heating Inc at (860) 535-2552, or visit the website to learn more about the products and services available.