As the weather starts to cool off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC costs can add up to a large piece of your monthly electric bill. To figure out new ways to reduce costs, some homeowners look closely at their thermostat. Is there a setting they can use to boost efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what can the fan setting offer for an HVAC system? This guide should help. We’ll share what exactly the fan setting is and when you can use it to save money in the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting means that the system’s blower fan keeps running. Certain furnaces can operate at a low level with this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will turn on the fan over a heating or cooling cycle and switch it off after the cycle is finished.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more uniform by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest as steady airflow will keep passing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps expand its life span. Because the air handler is usually a component of the furnace, this means you might avoid needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A continuous fan will likely increase your energy bills by a small margin.
  • Continuous airflow can clog your air filter in a shorter amount of time, increasing the frequency you should replace it.

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

During the summer, warm air will sometimes persist 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 severe heat, this may result in needing AC repair more regularly as wear and tear grows.

The reverse can occur 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 setting on may pump more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide if you should use the fan/on setting, don’t forget that every home and family’s comfort needs will vary. 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 tough on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help minimize these changes by steadily refreshing each room’s ventilation.