In order to avoid causing damage to the air conditioning unit do not operate, test or inspect the equipment when exterior temperatures are too cold (less than 65 F degrees for the last 24 hours)reguardless of the interior temperature. To operate the air conditioning when it is cold risks causing permanent damage to the unit. If you operate the air conditioning system when it is too cold out, it may function for a short time, but may NOT function next time it is operated. If you are buying a home during colder weather obtain a written representation from the seller indicating the system will be functioning properly during your walk through and or have it further evaluated by an air conditioning professional (who has the equipment and capability to test it during cold weather). Check the operation of the air conditioning during your walk through if the exterior temperature has been warm enough. If an air conditioning unit is functioning properly, the air temperature at a supply register will be 14 to 20 F degrees cooler than air at the return register.
