Once the weather begins to cool off, you might be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC costs can contribute a large portion of your monthly electric bill. To learn new ways to lower their HVAC bill, some homeowners look closer at their thermostat. Maybe there’s a setting they could use to increase efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what can the fan setting provide for your HVAC system? This guide should help. We’ll review what exactly the fan setting is and whether 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 means that the system's blower fan remains on. Certain furnaces can operate at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will start the fan over a heating or cooling cycle and turn it off once the cycle is complete.

There are advantages and disadvantages to switching on the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more consistent by allowing the fan to keep circulating air.
  • Indoor air quality should improve as continuous airflow will keep moving airborne particles through the air filter.
  • Fewer start-stop cycles for the system's fan helps expand its life span. Because the air handler is often connected to the furnace, this means you can avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A continuous fan will likely raise your energy bills somewhat.
  • Nonstop airflow could clog your air filter up more quickly, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

Through the summer, warm air can stick around in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system might gradually move this warm air into the rest of your home, compelling the HVAC system to work harder to keep up with the desired temperature. In extreme heat, this may result in needing AC repair more regularly as wear and tear increases.

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 could 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, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on could be best for you if:

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

Your home experiences hot and cold spots. Lots of homes wrestle with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help limit these changes by constantly refreshing each room’s ventilation.