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

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what will the fan setting provide for the HVAC system? This guide should help. We’ll review precisely what the fan setting is and when you can use it to cut costs in the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting means that the air handler’s blower fan stays on. A few furnaces will run at a low level with this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will run the fan through a heating or cooling cycle and turn it off when the cycle is complete.

There are benefits and drawbacks to using the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort requirements.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more balanced by allowing the fan to keep running.
  • Indoor air quality can increase as steady airflow will keep forcing airborne contaminants into the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps expand its life span. Because the air handler is often part of the furnace, this means you can avoid needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A nonstop fan could increase your energy expenses somewhat.
  • Continuous airflow could clog your air filter soon, increasing the frequency you will want to 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 can draw this warm air into the rest of your home, compelling the HVAC system to run longer to keep up with the set temperature. In serious heat, this can result in needing AC repair more regularly as wear and tear grows.

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

If you’re still trying to figure out if you should use the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could be ideal for you if:

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

Your home has hot and cold spots. Many homes deal with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help minimize these changes by consistently refreshing each room’s airflow.