When the weather starts to cool off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills routinely make up a large piece of your monthly electric bill. To learn new ways to save, some homeowners take a closer look at their thermostat. Is there a setting they could use to improve efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what does the fan setting offer 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 cut costs during the summer or winter.

My Thermostat Has a Fan Setting?

For the bulk of thermostats, the fan setting indicates that the HVAC blower fan keeps running. A few 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 start the fan during a heating or cooling cycle and shut it off once the cycle is finished.

There are benefits and drawbacks 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 every room more consistent by enabling the fan to keep circulating air.
  • Indoor air quality can increase as steady airflow will keep passing airborne pollutants through the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is often part of the furnace, this means you can prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A continuous fan could add to your energy expenses somewhat.
  • Constant 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 can stick around in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system might pull this warm air into the rest of your home, compelling the HVAC system to work more to keep up with the preferred temperature. In serious heat, this can result in needing AC repair more regularly as wear and tear gets worse.

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

If you’re still trying to decide if you should switch to the fan/on setting, don’t forget that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could work for you if:

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

Your home experiences hot and cold spots. All kinds of homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help limit these changes by steadily refreshing each room’s airflow.