As the weather starts to cool off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC costs frequently add up to a big portion of your monthly electric bill. To learn new ways to reduce costs, some homeowners take a closer look at their thermostat. Is there a setting they could use to boost efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what can the fan setting provide for the HVAC system? This guide should help. We’ll walk through what exactly the fan setting is and whether you can use it to reduce costs during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting signifies that the air handler’s blower fan remains on. Some furnaces will operate at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and shut it off once the cycle is over.

There are advantages and disadvantages to switching on the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your unique comfort preferences.

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by permitting the fan to keep running.
  • Indoor air quality will be highest because constant airflow will keep forcing airborne particles through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps expand its life span. Since the air handler is often connected to the furnace, this means you could minimize the risk of needing furnace repair.

Downsides to using the Fan/On setting:

  • A continuous fan will likely increase your energy expenses somewhat.
  • Constant airflow may clog your air filter soon, increasing the frequency you should replace it.

Which Setting for My Thermostat? Fan or Auto in Summer/Winter

In the summer, warm air will sometimes stick around in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system might pull this warm air into the rest of your home, forcing the HVAC system to run longer to preserve the set temperature. In serious heat, this can result in needing AC repair more quickly as wear and tear grows.

The reverse can happen in the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually drift into the rest of your home. Leaving the fan setting on may pump 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, don’t forget that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on might be best for you if:

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

Your home deals with 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 should help minimize these changes by constantly refreshing each room’s supply of air.