The risk of oversized home HVAC systems


HVAC systems are present in most homes in the United States. They offer heating, ventilation, and air conditioning throughout the entire home, making them a necessity anywhere that experiences hot summers, cold winters, and high levels of pollution (including wildfire smoke). Click here to learn more about energy efficient HVAC in Portland and HVAC in Bend, Oregon.

Since HVAC units are such a boon, some people may want the biggest, strongest, and the best version available on the market -- because bigger is always better, right? Wrong! When it comes to your HVAC unit, efficiency depends entirely on matching your system to your home: if you have a small home and an oversized system, you may experience any number of the following problems and risks.

  • Inconsistent temperatures: Oversizing refers to the amount of energy needed to change the temperature and is typically measured in BTUs. By installing a 50,000 BTU unit in a home that only requires a fraction of that heating and cooling capacity, the temperature change won't be gradual. The system will work so quickly that you may find hot or cold spots throughout the home, as well as moisture-laden air that feels clammy (which most people find extremely uncomfortable).

  • Short cycling: By blasting your home with hot or cool air rather than a gradual change, the temperature swings will prompt your unit to start up and shut down in rapid succession (called short cycling). This can cause a tremendous amount of wear and tear on the compressor, blower fan motor, and other vital components -- all of which can be costly to repair and replace.

  • Shorter lifespan: The average residential HVAC system -- if it's the right size -- can last between 15 and 20 years as long as it receives the proper care and maintenance. Oversize units, however, suffer from the damage short cycling causes and degrade at a much faster rate.

If you're positive your HVAC system is the right size for your home yet you're still experiencing temperature problems, you may want to consider contacting insulation contractors; poorly insulated attics can account for 25% of a home's heat loss, and single-pane windows can contribute to heat loss and gain. Of course, it might also just be that you need to schedule HVAC repairs. Regardless of your needs, there is a company out there to lend a hand.

Steffan Kasula