Once the weather begins to cool off, you may be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses can contribute a large piece of your monthly electric bill. To try and find ways to reduce costs, some people look closer at their thermostat. Is there a setting they should use to boost efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what will the fan setting offer for the HVAC system? This guide can help. We’ll review just what the fan setting is and when you can use it to cut costs over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting signifies that the air handler’s blower fan keeps running. A few furnaces may continue to operate at a low level in this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will run the fan through a heating or cooling cycle and shut it off after the cycle is over.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more consistent by permitting the fan to keep generating airflow.
  • Indoor air quality should improve since continuous airflow will keep moving airborne pollutants into the air filter.
  • Fewer start-stop cycles for the system's fan helps extend its life span. As the air handler is typically a component of the furnace, this means you might avoid needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A continuous fan can raise your energy expenses slightly.
  • Constant airflow can clog your air filter soon, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

Through the summer, warm air may stick around in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system might draw this warm air into the rest of your home, forcing the HVAC system to work more to keep up with the preferred temperature. In serious heat, this can result in needing AC repair more regularly as wear and tear gets worse.

The reverse can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Keeping the fan on will sometimes draw more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to determine if you should switch to the fan/on setting, keep in mind 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 other respiratory conditions can be hard on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. All kinds 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 might help limit these changes by consistently refreshing each room’s airflow.