When 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 expenses routinely add up to a significant piece of your monthly electric bill. To try and find ways to save, some homeowners take a closer look at their thermostat. Could there be a setting they can use to increase efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what will the fan setting provide for your HVAC system? This guide should help. We’ll walk through just what the fan setting is and whether you can use it to reduce costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting indicates that the air handler’s blower fan remains on. Certain furnaces may continue to generate heat at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will start the fan over a heating or cooling cycle and turn it off once the cycle is over.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in each room more balanced by allowing the fan to keep circulating air.
  • Indoor air quality should improve as constant airflow will keep moving airborne particles through the air filter.
  • Fewer start-stop cycles for the blower fan helps lengthen its life span. Because the air handler is often a component of the furnace, this means you might avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A continuous fan can add to your energy expenses by a small margin.
  • Nonstop airflow may clog your air filter up more quickly, increasing the frequency you should replace it.

Should My Thermostat Be on Fan or Auto in Summer/Winter

Through the summer, warm air may persist in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system may draw this warm air into the rest of your home, compelling the HVAC system to work harder to preserve the desired temperature. In severe heat, this can lead to needing AC repair more regularly as wear and tear gets worse.

The opposite can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually drift into the rest of your home. Keeping the fan on will sometimes draw more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide if you should switch to the fan/on setting, keep in mind 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 suffers from allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. All kinds 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 lessen these changes by consistently refreshing each room’s ventilation.