When the weather begins to cool off, you are probably thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely add up to a significant piece of your monthly electric bill. To learn new ways to reduce costs, some people take a closer look at their thermostat. Maybe there’s a setting they can use to boost efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what will the fan setting provide for an HVAC system? This guide should help. We’ll review precisely what the fan setting is and when you can use it to reduce costs in the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting means that the system’s blower fan keeps running. Some furnaces may continue to generate heat at a low level in this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will run the fan over a heating or cooling cycle and turn it off when the cycle is finished.

There are benefits and drawbacks to trying the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort preferences.

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 since continuous airflow will keep forcing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps expand its life span. Since the air handler is usually connected to the furnace, this means you could prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A nonstop fan will likely raise your energy bills somewhat.
  • Continuous airflow could clog your air filter in a shorter amount of time, increasing the frequency you’ll need to replace it.

Should My Thermostat Be on? Fan or Auto in Summer/Winter

In the summer, warm air will sometimes linger in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system can gradually move this warm air into the rest of your home, pushing the HVAC system to work harder to preserve the preferred temperature. In severe heat, this can result in needing AC repair more often as wear and tear gets worse.

The opposite can happen in 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 setting on could draw more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to decide 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 could be best for you if:

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

Your home experiences hot and cold spots. All kinds of homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help limit these changes by consistently refreshing each room’s ventilation.