Once the weather begins to cool off, you may be thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills can make up a significant portion 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 should use to boost efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what will the fan setting offer for an HVAC system? This guide will help. We’ll share just what the fan setting is and how you can use it to reduce costs in the summer or winter.

What Is the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting means that the HVAC blower fan keeps running. Certain furnaces will generate heat at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will run the fan during a heating or cooling cycle and turn it off after the cycle is complete.

There are advantages and disadvantages to switching on the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your distinct comfort preferences.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by permitting the fan to keep circulating air.
  • Indoor air quality can increase because continuous airflow will keep passing airborne contaminants through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. As the air handler is typically part of the furnace, this means you can prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A nonstop fan can raise your energy costs slightly.
  • Continuous airflow could clog your air filter up more quickly, increasing the frequency you’ll need to replace it.

Which Setting for My Thermostat? Fan or Auto in Summer/Winter

In the summer, warm air can persist 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, pushing the HVAC system to run longer to preserve the set temperature. In severe heat, this can lead to needing AC repair more quickly as wear and tear grows.

The reverse can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan running will sometimes pull more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide if you should switch to the fan/on setting, don’t forget that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be best for you if:

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

Your home experiences hot and cold spots. All kinds of homes wrestle with stubborn 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.