When the weather starts to cool off, you might be wondering about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely add up to a large chunk of your monthly electric bill. To learn new ways to reduce costs, some people take a closer look at their thermostat. Maybe there’s a setting they could use to boost efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what will the fan setting offer for the HVAC system? This guide will help. We’ll review what exactly the fan setting is and whether you can use it to cut costs during the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting means that the system’s blower fan stays on. Certain furnaces may continue to generate heat at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will run the fan during a heating or cooling cycle and turn it off once the cycle is complete.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more uniform by allowing the fan to keep generating airflow.
  • Indoor air quality should improve because continuous airflow will keep passing airborne particles into the air filter.
  • Fewer start-stop cycles for the HVAC fan helps lengthen its life span. Because the air handler is typically connected to the furnace, this means you might minimize the risk of needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A nonstop fan can raise your energy expenses somewhat.
  • Nonstop airflow can clog your air filter up more quickly, increasing the frequency you’ll need 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 may persist in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system may gradually move this warm air into the rest of your home, pushing the HVAC system to run longer to keep up with the desired temperature. In extreme heat, this can lead to needing AC repair more often as wear and tear grows.

The reverse can occur in the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually flow into the rest of your home. Keeping the fan on will sometimes pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to decide if you should use the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be best for you if:

Someone in your household suffers from allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on can help to enhance indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help minimize these changes by constantly refreshing each room’s supply of air.