The lifespan of most modern high-efficiency, air conditioning units is typically measured in decades rather than just years. Even the best maintained unit will sometimes not provide air that is sufficiently cold. There are several reasons your air conditioning may be producing hot air.
From simplest to most difficult to repair, they are:
Condenser is Frozen
The lack of regular maintenance or operator error is the usual culprit in this situation. Air conditioning systems are designed to deliver a steady stream of cooled air and to maintain a reasonable level of comfort in the home. They are not, in fact, designed to run continuously.
To this end, regular maintenance must be performed to ensure that the unit runs at an optimal level. Lacking this maintenance, dirty air filters, clogged drains and obstructed evaporator coils will eventually freeze up from overuse. The unit will cease to function adequately. If your coils are frozen, do some basic maintenance and your AC unit should again function properly.
Low Level or Lack of Refrigerant
Refrigerant is the “magic” ingredient that transfers heat from the exterior evaporator coils to the blowers inside the house. Without sufficient levels of this liquid, heat transfer is incompletely performed. Consequently, the entire system is overloaded and eventually shuts down.
A professional HVAC repair tech is usually needed to check and refill the refrigerant. Be sure that he also checks for any leaks in the line. By the way, regular maintenance should also eliminate this problem before it occurs.
The condenser is the part of the air conditioning unit that, unlike its name, expands a liquid to lower its temperature. It is the most essential part of the unit. If it fails, the air conditioning unit will not function at all. Condensers do not fail that often and are covered by all manufacturers’ warranties for a limited time. Unfortunately, as they age, HVAC units will eventually fail. Careful consideration should be given to upgrading an aged system when a condenser fails.
Homeowners usually know when their air conditioning unit is on its last legs. So, when an AC starts blowing hot air, the savvy homeowner should know whether the problem is easily fixed or more severe. In either case, the advice of a professional HVAC company is worth obtaining.