Air Conditioner Freezing Up

Air Conditioner is Freezing

Freezing of your AC coil occurs when the refrigerant inside a central air conditioning unit falls below 32 degrees Fahrenheit, Canadians would measure it as 0 degrees Celcius. What is actually happening is the humidity that surrounds the coils is freezing up. The coils become encased in ice and the air conditioning unit fails to cool the home properly. Once you’ve thawed the coils, you have several options before calling a repair person to fix the unit. Just be sure to turn off the air conditioner first. Running the unit with the coils iced over can strain the compressor and cause major damage to the unit.

Usually Coils freezing up means low air flow or a slight undercharge of refrigerant. Low air flow is the most common. It could be a result of a dirty filter, dirty ductwork, damaged evaporator coil, restrictions in the ductwork or even a mismatched system where the outside unit is to large for the evaporator coil inside the furnace.

Thawing the AC Coil

Don’t be tempted to help the thawing process by removing chunks of ice by hand, resist that temptation. The coils and cooling fins in the evaporator portion of the central air conditioner can be easily damaged. Ice clings tightly to these components, and forcefully removing it can bend fins or rupture the coolant lines. It is a good idea to turn off the power to the the air conditioner and the fan on the furance. You do not want water to drip down into the furnace and possibly damage electrical component boards inside the furane . Thawing may still take several hours.

Possible Quick Fixes

One of the first things to check is the filter. If they are dirty or clogged, replace them with clean ones. Another cause of restricted airflow occurs when too many supply registers are closed. Check all the rooms in the house and make sure the supply registers are open. Clogged and dirty cooling fins in the frame that surrounds the coils might strain the system enough to cause icing. If outside air temperatures fall below 60 degrees Fahrenheit, 16 degrees Celsius most central air conditioners do not work properly. Consider shutting the system off when temperatures fall below 60 degrees.

Topping Up Refrigerant

This is not a Do It Your Self Job. Call your local qualified service technician to check and refill refrigerant. Air conditioning repair people understand how to work with the pressurized refrigerant system and will be able to quickly determine which type of refrigerant your system needs.


Cleaning The Ductwork

Frequently when Power Vac is cleaning ductwork we do find blockages in the evaporator coils inside the furnace. Blocked coils are a result of the fins of the evaporator coil getting plugged up . The close spacing of the aluminum fins on an evaporator coil makes it easy for dirt, dust and other debris to stick. Lodged debris causes blockages, affecting the overall performance and efficiency of your air conditioning. Air flow across the coil becomes blocked, degrading heat transfer. Blockages come in the form of build-up from skin cells, fabric fibers, pet hair, grass clippings, tobacco smoke, pollen, mud, rust and bacteria.


Dirty AC Coil

Published by darwyn mcdowell

Darwyn has been involved with Power Vac since 1989. He has an extensive marketing background in the HVAC Remediation industry . He holds his ASCS and VSMR through NADCA. Connect with Darwyn at Google +