Once the weather starts to cool off, you are probably wondering about how you’ll prepare your heating and cooling. After all, HVAC bills routinely add up to a big chunk of your monthly electric bill. To learn new ways to reduce costs, some owners look closely at their thermostat. Is there a setting they could use to increase efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what does the fan setting provide for the HVAC system? This guide can help. We’ll share just what the fan setting is and when you can use it to save money during the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the system’s blower fan stays on. A few furnaces can operate at a low level in this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and switch it off when the cycle is finished.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more uniform by enabling the fan to keep running.
  • Indoor air quality will be highest because continuous airflow will keep forcing airborne particles into the air filter.
  • Fewer start-stop cycles for the system’s fan helps extend its life span. Since the air handler is typically a component of the furnace, this means you might prevent the need for furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A constant fan could add to your energy bills slightly.
  • Nonstop airflow may clog your air filter in a shorter amount of time, 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

In the summer, warm air will sometimes persist in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system can draw this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the desired temperature. In extreme heat, this could result in needing AC repair more regularly as wear and tear grows.

The opposite can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually flow into the rest of your home. Keeping the fan on could draw more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to figure out 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 work 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 increase indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Lots of homes deal with difficult 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 constantly refreshing each room’s ventilation.