Once the weather is cooling off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills can add up to a significant portion of your monthly electric bill. To learn new ways to save, some owners look closer at their thermostat. Is there a setting they should use to boost efficiency?

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what will the fan setting offer for an HVAC system? This guide can help. We’ll walk through just what the fan setting is and how you can use it to save money during the summer or winter.

Should I Use My Thermostat's Fan Setting?

For the majority of thermostats, the fan setting means that the system's blower fan keeps running. Some furnaces will generate heat at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will turn on the fan during a heating or cooling cycle and shut it off once the cycle is complete.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more balanced by permitting the fan to keep running.
  • Indoor air quality should improve since continuous airflow will keep forcing airborne contaminants into the air filter.
  • Fewer start-stop cycles for the system's fan helps expand its life span. As the air handler is typically part of the furnace, this means you could prevent the need for furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A continuous fan could increase your energy bills somewhat.
  • Nonstop airflow may 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 Summer/Winter

During 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 might gradually move this warm air into the rest of your home, compelling the HVAC system to work harder to preserve the set temperature. In serious heat, this could result in needing AC repair more quickly as wear and tear grows.

The opposite can take place in the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually flow into the rest of your home. Keeping the fan on could pump more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to determine 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 could work for you if:

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

Your home has hot and cold spots. Lots of homes wrestle with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help lessen these changes by steadily refreshing each room’s airflow.