When the weather is cooling off, you might be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills can make up a large portion of your monthly electric bill. To figure out new ways to reduce costs, some owners look closer at their thermostat. Could there be a setting they could use to boost efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what does the fan setting provide for an HVAC system? This guide can help. We’ll walk through just what the fan setting is and whether you can use it to cut costs during the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting means that the HVAC blower fan stays on. Certain 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, in contrast, will start the fan through a heating or cooling cycle and shut it off after the cycle is over.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature in each room more uniform by enabling the fan to keep running.
  • Indoor air quality should improve since continuous airflow will keep moving airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps expand its life span. Since the air handler is often part of the furnace, this means you might avoid needing furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A constant fan could increase your energy bills by a small margin.
  • Nonstop airflow could 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 Each Season

During 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 maintain the desired temperature. In serious heat, this can lead to needing AC repair more regularly as wear and tear grows.

The opposite can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually drift into the rest of your home. Leaving the fan running may 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, don’t forget that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may work for you if:

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

Your home experiences hot and cold spots. Lots of homes deal with difficult hot and cold spots that quickly return 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.