When the weather starts to cool off, you might be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC costs routinely add up to a big piece of your monthly electric bill. To figure out new ways to reduce costs, some homeowners look closer at their thermostat. Maybe there’s a setting they should use to boost efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what will the fan setting offer for your HVAC system? This guide can help. We’ll share what exactly 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 the majority of thermostats, the fan setting indicates that the HVAC blower fan stays on. A few furnaces may continue to operate at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will turn on the fan through a heating or cooling cycle and switch it off when the cycle is complete.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more balanced by permitting the fan to keep circulating air.
  • Indoor air quality should improve as steady airflow will keep moving airborne contaminants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps lengthen its life span. As the air handler is often a component of the furnace, this means you can minimize the risk of needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A nonstop fan could raise your energy bills somewhat.
  • Continuous airflow can clog your air filter soon, increasing the frequency you’ll need to replace it.

Should My Thermostat Be on? Fan or Auto in Each Season

In the summer, warm air can stick around in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to run longer to preserve the set temperature. In extreme heat, this can lead to needing AC repair more often as wear and tear grows.

The opposite can occur in the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Keeping the fan on could pump more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to determine if you should try the fan/on setting, remember 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 similar 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 has hot and cold spots. Many homes wrestle with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help minimize these changes by constantly refreshing each room’s supply of air.