As the weather starts to cool off, you might be wondering about how you’ll make the most of your heating and cooling. After all, HVAC expenses routinely make up a significant piece of your monthly electric bill. To try and find ways to save, some people look closely at their thermostat. Could there be a setting they can use to increase efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what can the fan setting offer for an HVAC system? This guide should help. We’ll review just what the fan setting is and whether you can use it to save money in the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting indicates that the air handler’s blower fan keeps running. A few furnaces may continue to operate at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will turn on the fan through a heating or cooling cycle and switch it off once the cycle is over.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in each room more uniform by allowing the fan to keep generating airflow.
  • Indoor air quality should improve as constant airflow will keep forcing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps extend its life span. As the air handler is often connected to the furnace, this means you could avoid needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A continuous fan can raise your energy costs by a small margin.
  • Constant airflow can clog your air filter soon, increasing the frequency you should replace it.

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

During the summer, warm air may persist in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to work more to keep up with the set temperature. In severe heat, this can lead to needing AC repair more often as wear and tear gets worse.

The reverse can occur over 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 could pull more cold air upward, increasing the amount of heating you need to remain 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 will vary. Leaving the HVAC system’s fan on may be ideal for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be tough 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. All kinds of homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help lessen these changes by constantly refreshing each room’s supply of air.