Originally Posted by Shadowcatche
Two possible causes, fan not working properly (easy to tell) or freon charge is low (most likely). I know sounds counter intuitive but a low freon charge will cause an AC to freeze up. A competent HVAC place should be able to service the unit.
Actually, low refrigerant (Freon) is the least likely reason for the A/C freezing. 9 time out of 10 the issue if low air flow. Save your self some money and do some simple maintenance on your A/C.
-Take off the inside cover and clean the filters. They need to be cleaned about every 2 weeks of normal use.
-Next, look up in the unit to the evaporator coil. It should be clear of any lint built up.
-Check the unit housing for any internal bypass leaks of the air. Air leaking from the outlet side of the fan assembly to the inlet will cause it to freeze up.
-DO NOT run the fan on low speed.
-Check to see that the freeze sensor bulb is located correctly and embedded in the evaporator coil.
-DO not try to run the unit at 72 deg F. Raise the T'stat a couple of degrees and let the unit cycle off..
I have been working with refrigeration and A/C for over 40 years and have heard about every wives tale there is for A/C. The most common one is low Freon which is most often not the case with a hermetic (sealed) unit.