Once the weather starts to cool off, you may be thinking about how you’ll make the most of your heating and cooling. After all, HVAC costs frequently make up a big portion of your monthly electric bill. To figure out new ways to save, some homeowners take a closer look at their thermostat. Maybe there’s a setting they can use to boost efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what can the fan setting offer for the HVAC system? This guide should help. We’ll walk through what exactly the fan setting is and whether you can use it to save money over the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For most thermostats, the fan setting signifies that the air handler’s blower fan keeps running. Some furnaces may continue to run at a low level with this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will run the fan during a heating or cooling cycle and shut it off when the cycle is finished.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by allowing the fan to keep generating airflow.
  • Indoor air quality should improve as steady airflow will keep moving airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps lengthen its life span. Because the air handler is typically connected to the furnace, this means you might avoid needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan will likely increase your energy bills slightly.
  • Nonstop airflow may clog your air filter up more quickly, increasing the frequency you should replace it.

Which Setting for My Thermostat? Fan or Auto in Each Season

In the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system can pull this warm air into the rest of your home, forcing the HVAC system to work more to preserve the desired temperature. In serious heat, this could result in needing AC repair more regularly as wear and tear grows.

The opposite can occur over the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan setting on may pump 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 try the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could be ideal for you if:

Someone in your household deals with 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 deals with hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help lessen these changes by steadily refreshing each room’s supply of air.