When the weather starts to cool off, you might be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses can add up to a big piece of your monthly electric bill. To learn new ways to reduce costs, some homeowners take a closer look at their thermostat. Could there be a setting they can use to improve efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what does the fan setting provide for your HVAC system? This guide will help. We’ll share just what the fan setting is and how you can use it to cut costs over the summer or winter.

Should I Use My Thermostat's Fan Setting?

For the majority of thermostats, the fan setting signifies that the air handler’s blower fan stays on. Certain furnaces will operate at a low level with this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will run the fan over a heating or cooling cycle and switch it off after the cycle is finished.

There are advantages and disadvantages to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your personal comfort requirements.

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more balanced by permitting the fan to keep circulating air.
  • Indoor air quality will be highest since continuous airflow will keep forcing airborne particles through the air filter.
  • A smaller number of start-stop cycles for the system's fan helps lengthen its life span. Since the air handler is typically part of the furnace, this means you can avoid needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A nonstop fan could increase your energy costs somewhat.
  • Nonstop airflow may clog your air filter soon, increasing the frequency you’ll need to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

Through the summer, warm air can linger in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system can pull this warm air into the rest of your home, pushing the HVAC system to work harder to maintain the preferred temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear grows.

The opposite can occur in the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually flow into the rest of your home. Leaving the fan running will sometimes pump more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to decide if you should try the fan/on setting, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be best for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. All kinds of homes wrestle with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help limit these changes by consistently refreshing each room’s ventilation.