Advice for making sure your air conditioner is the right size for your living space usually revolves around window units rather than a central air conditioner. But an improperly sized central unit can cause a wide range of problems that can leave your house too hot, too humid, or too costly with utility bills. If you're experiencing any of the problems below, call an air conditioning repair and installation company like Shivani Refrigeration & Air Conditioning for a consultation, troubleshooting, and a new unit, if needed.
Unit Constantly Runs—or Shuts Off Too Quickly
Does your air conditioner run most of the time yet the indoor temperature never seems to reach the number on the thermostat? This can be an issue with the compressor or with the thermostat sensor. But it is also one of the most common signs that your air conditioner is too small for your living area.
An undersized unit has to work overtime to try and get the air cold enough in your home to match the thermostat. Depending on how low the thermostat is set, your unit might not ever be able to get the indoor temperature to match and will just keep running -- and sending your utility bills up through the roof.
While constantly running units are a problem, a unit that shuts off too quickly isn't good, either. Rapid cycling can be a sign that the unit is too large for your home. So the unit cools quicker than average, which means it conducts more but shorter cycles over the lifespan of the unit. That rapid cycling can actually shorten the lifespan of the unit.
Excess Indoor Humidity
Is the air inside your home humid and clammy even when the air conditioner is running? The rapid cycling of an oversized unit can cause this problem.
A normal cooling cycle provides enough time from the air conditioner to strip moisture out of the air that's coming into the air handler then passing over the cool and damp evaporator coils. But if the air is moving too quickly through the system—or less air is entering at all—then you can be left with excess humidity inside your home.
This problem can persist even if your unit has a built-in dehumidifier as the principles of rapid cycling still apply.
Frozen Evaporator Coils
You might be happy at this point if your problem isn't rapid cycling. But constant running can pose its own problems inside your system. The frequent passing through of refrigerant can end up freezing up the evaporator coils inside the air handler. Eventually, the frozen coils will no longer let the refrigerant pass through properly and your unit will become less efficient.
Contact an HVAC company if you suspect your unit is the wrong size. The technician can perform troubleshooting to make sure it isn't a more minor problem and advise you on the best unit size for your home.