By: Patricia Cermignano

One of the biggest misconceptions when purchasing a new cooling or heating system is believing that an over-sized HVAC unit performs better than a correctly sized HVAC unit. However, this theory could not be further from the truth. In fact, having an over-sized HVAC system installed in your home could cause many issues to your home's overall comfort level. As we see value in understanding this concept, we wanted to focus on this topic for our September Tech Tip of the Month.


How Do You Know If Your Cooling System or Heating System Is Over-Sized?

Cooling System: If your cooling system is over-sized, it will cool your space in a very short amount of time; however, as a result, the system tends to short cycle more frequently. When your cooling system short cycles, it prevents your home from properly dehumidifying as the system does not run long enough to allow the air to blow across the indoor coil where the moisture condenses into water and drains into your system. This excess moisture in the air can lead to mold and mildew problems. Another issue with your cooling system short cycling is that it requires more energy to start and stop the unit more often. This also leads to a greater chance of your system sustaining more wear and tear.

Heating System: If your heating system is over-sized, it will warm your space in a very short amount of time; however, this may result in greater temperature swings in your home. When your heating system quickly turns on and off, not only does it require more energy to run, but the house often heats too quickly for the thermostat to adjust to the temperature change. This leaves some rooms uncomfortably warm and others uncomfortably cold.

Other issues we tend to see with over-sized HVAC systems are:

  • Frequent system breakdowns
  • Reduced life span on the equipment
  • Increase in utility bills
  • Inconsistent temperatures throughout your home
  • Noisy system
  • Indoor air quality issues
  • Higher price to purchase, operate and maintain


If you are in the market for having a new HVAC system installed in your home, we recommend calling the HVAC professionals at Bob Cermignano Air Conditioning in Heating, Inc. With over 37 years of experience, our HVAC professionals know how to properly measure the space in your home to help find the properly sized cooling or heating system. For more information, please give our office a call at 610-642-6323 or visit our website at