Once the weather starts to cool off, you are probably thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills frequently add up to a big chunk 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 can use to boost efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what does the fan setting offer for your HVAC system? This guide can help. We’ll review what exactly the fan setting is and how you can use it to reduce costs during the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the majority of thermostats, the fan setting means that the air handler’s blower fan stays on. Some furnaces can generate heat at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will turn on the fan during a heating or cooling cycle and turn it off once the cycle is finished.

There are pros and cons to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your distinct comfort preferences.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in each room more consistent by enabling the fan to keep circulating air.
  • Indoor air quality will be highest because steady airflow will keep passing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the blower fan helps lengthen its life span. Because the air handler is usually connected to the furnace, this means you might avoid needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A continuous fan could add to your energy bills slightly.
  • Constant airflow can clog your air filter soon, increasing the frequency you will want to replace it.

Should My Thermostat Be on? Fan or Auto in Summer/Winter

Through the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system can draw this warm air into the rest of your home, forcing the HVAC system to run longer to preserve the desired temperature. In extreme heat, this can result in needing AC repair more regularly as wear and tear grows.

The opposite can happen in the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Leaving the fan setting on may draw more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to determine if you should try 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 may work for you if:

Someone in your household deals with 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 experiences hot and cold spots. Lots of homes wrestle with difficult hot and cold spots that quickly shift 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.