Once the weather starts to cool off, you may be concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills can make up a large chunk of your monthly electric bill. To try and find ways to reduce costs, some owners look closer at their thermostat. Is there a setting they could use to improve efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what does the fan setting offer for the HVAC system? This guide should help. We’ll share precisely what the fan setting is and whether you can use it to cut costs in the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting indicates that the system's blower fan keeps running. Certain furnaces may continue to run at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will start the fan through a heating or cooling cycle and switch it off after the cycle is complete.

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

Advantages to utilizing 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 will be highest as steady airflow will keep passing airborne contaminants through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is often part of the furnace, this means you might minimize the risk of needing furnace repair.

Disadvantages to using the Fan/On setting:

  • A nonstop fan can add to your energy bills slightly.
  • Nonstop airflow may clog your air filter up more quickly, increasing the frequency you will want to replace it.

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

Through the summer, warm air may stick around in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system might pull this warm air into the rest of your home, forcing the HVAC system to work more to keep up with the desired temperature. In severe heat, this may lead to needing AC repair more regularly as wear and tear gets worse.

The opposite can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running may pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to determine 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 might be ideal for you if:

Someone in your household has allergies. Allergies and similar 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 deals with hot and cold spots. Many homes wrestle with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help limit these changes by steadily refreshing each room’s airflow.