Once the weather starts to cool off, you may be wondering about how you’ll make the most of your heating and cooling. After all, HVAC bills can add up to a significant chunk of your monthly electric bill. To figure out new ways to reduce costs, some homeowners look closely at their thermostat. Is there a setting they could use to boost efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what will the fan setting offer for an HVAC system? This guide can help. We’ll review just what the fan setting is and how you can use it to cut costs during the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the majority of thermostats, the fan setting indicates that the air handler’s blower fan remains on. Some furnaces may continue to run at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will run the fan over a heating or cooling cycle and shut it off after the cycle is over.

There are advantages and disadvantages to trying the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your personal comfort needs.

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more balanced by permitting the fan to keep generating airflow.
  • Indoor air quality can increase because continuous airflow will keep forcing airborne contaminants into the air filter.
  • Fewer start-stop cycles for the blower fan helps lengthen its life span. As the air handler is usually part of the furnace, this means you might minimize the risk of needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan can raise your energy expenses slightly.
  • Continuous airflow could clog your air filter soon, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

During the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system can pull this warm air into the rest of your home, forcing the HVAC system to work more to preserve the preferred temperature. In serious heat, this can result in needing AC repair more regularly as wear and tear grows.

The opposite can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually drift into the rest of your home. Leaving the fan setting on will sometimes draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may work for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on is more likely to increase indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Many homes wrestle with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help limit these changes by constantly refreshing each room’s airflow.