Last summer my AC was working over time and I experienced the dreaded air conditioner freeze!, Naturally, I wanted to know why it froze and how to prevent a recurrence. Here is what I found out. Its the evaporator coil in the central A/C unit that actually freezes. This component of the air conditioner transfers heat from the inside to the outside of your area home.
Here are the most common reasons an Air Conditioner freezes!
- Insufficient or restricted air flow:- Now, although I know better, I neglected changing my A/C filter – oops!. If the filter in your Air conditioning unit is dirty or clogged, then the air will not be able to pass through it at an efficient rate. When air passes too slowly across the cooling coil, moisture accumulates and freezes. As the ice builds up, the systems cooling capacity diminishes. The same would happen if I had obstructed and undersized ducts; damaged blower motors; dirt build-up on the evaporator coil or if too many of the vents in the home is closed off.
- Not enough refrigerant in your A/C system:- The second most common reason for air conditioning freeze-ups is a loss of refrigerant. Refrigerant leaks can cause pressure drops in the air conditioner’s evaporator coil. When this happens, it allows moisture in the air to freeze and accumulate on the coil. Refrigerant should not leak in well-maintained systems. However, under-serviced AC systems can leak due to wear and tear.
- Thermostat and Outdoor Temperature Issues:- If your thermostat is malfunctioning, then this can cause your A/C Unit to freeze up. Your thermostat should switch off at the correct temperature. If it does not shut off and the AC continues to run, then you know you have a problem with the thermostat. This is especially true of very old models.
Did you know that Most outdoor air conditioning units do not function well in temperatures below 60 degrees F. If night-time temperatures are too low, the system will not operate properly and freeze-ups can occur.
What Should You Do When Your Air Conditioner Freezes?
Turn it off! don’t try to thaw the system by increasing the temperature at the thermostat. Just turn it off and allow the unit to defrost completely. Once it has defrosted, check the airflow. Clean or replace dirty filters or remove any visible dirt or obstructions; in some cases, this could be all that is needed, if this is the case, time to do a happy dance:) ’cause you just saved a fortune. Next, set up an alert on you smart phone to remind you to change the filter – you are welcome.
More serious airflow and refrigeration problems require professional intervention. Schedule a Service Call with your HVAC company. Certified technicians should have all the tools necessary to troubleshoot serious air flow problems and repair refrigerant leaks.
If your icing problem is due to drops in the outdoor air temperature, be sure to turn your air conditioner off when the mercury takes a drop. You should also consider installing a special ambient temperature control that will allow the unit to run properly in cooler temperatures.
