As the weather starts to cool off, you are probably thinking about how you’ll prepare your heating and cooling. After all, HVAC expenses routinely contribute a significant portion of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners take a closer look at their thermostat. Is there a setting they can use to boost efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what can the fan setting provide for an HVAC system? This guide will help. We’ll share just what the fan setting is and when you can use it to save money over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting signifies that the air handler’s blower fan keeps running. Certain furnaces will run at a low level with this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will turn on the fan through a heating or cooling cycle and shut it off once the cycle is over.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more balanced by allowing the fan to keep circulating air.
  • Indoor air quality can increase since steady airflow will keep moving airborne contaminants into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps extend its life span. As the air handler is typically part of the furnace, this means you can prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan can raise your energy bills slightly.
  • Constant airflow can clog your air filter soon, 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 Summer/Winter

In the summer, warm air will sometimes linger in unfinished spaces like 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, pushing the HVAC system to run longer to keep up with the set temperature. In serious heat, this could result in needing AC repair more often as wear and tear grows.

The opposite can occur in 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 may 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, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might work for you if:

Someone in your household has allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on is more likely to increase 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 lessen these changes by constantly refreshing each room’s ventilation.