Once the weather is cooling off, you are probably concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely contribute a big piece of your monthly electric bill. To learn new ways to reduce costs, some people take a closer look at their thermostat. Is there a setting they should use to boost efficiency?

The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what will the fan setting provide for your HVAC system? This guide should help. We’ll walk through what exactly the fan setting is and when you can use it to save money during the summer or winter.

Should I Use My Thermostat's Fan Setting?

For the bulk of thermostats, the fan setting signifies that the air handler’s blower fan keeps running. Some furnaces can operate at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will start the fan through a heating or cooling cycle and turn it off once the cycle is finished.

There are benefits and drawbacks to trying the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your personal comfort preferences.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by enabling the fan to keep circulating air.
  • Indoor air quality will be highest since continuous airflow will keep moving airborne pollutants into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is typically a component of the furnace, this means you might avoid needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A nonstop fan could add to your energy bills somewhat.
  • Continuous airflow could 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 may stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system might draw this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the preferred temperature. In serious heat, this could lead to needing AC repair more quickly as wear and tear increases.

The reverse can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually flow into the rest of your home. Leaving the fan setting on will sometimes pump more cold air upward, increasing the amount of heating you need to keep 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 not the same. Leaving the HVAC system’s fan on might be ideal for you if:

Someone in your household has allergies. Allergies and similar respiratory conditions can be hard 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. Many homes wrestle with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help minimize these changes by constantly refreshing each room’s airflow.