When the weather begins to cool off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC costs can make up a significant portion of your monthly electric bill. To try and find ways to reduce costs, some owners look closely at their thermostat. Could there be a setting they can use to increase efficiency?

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

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting means that the HVAC blower fan stays on. Certain furnaces may continue to run at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will run the fan through a heating or cooling cycle and turn it off once the cycle is complete.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more balanced by enabling the fan to keep running.
  • Indoor air quality can increase because continuous airflow will keep moving airborne contaminants into the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is typically part of the furnace, this means you might prevent the need for furnace repair.

Downsides to utilizing the Fan/On setting:

  • A continuous fan can increase your energy bills by a small margin.
  • Nonstop airflow may 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 Each Season

During the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system might draw this warm air into the rest of your home, forcing the HVAC system to work harder to keep up with the desired temperature. In extreme heat, this can lead to needing AC repair more often as wear and tear grows.

The reverse can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan setting on will sometimes pull more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide 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 could 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 deals with hot and cold spots. Many homes wrestle with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help lessen these changes by constantly refreshing each room’s airflow.