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

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

Should I Use My Thermostat’s Fan Setting?

For the bulk of thermostats, the fan setting indicates that the system’s blower fan keeps running. A few furnaces may continue to run at a low level in this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will turn on the fan over a heating or cooling cycle and switch it off when the cycle is over.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more balanced by enabling the fan to keep circulating air.
  • Indoor air quality should improve since steady airflow will keep forcing airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps expand its life span. As the air handler is typically a component of the furnace, this means you might avoid needing furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A continuous fan will likely increase your energy costs somewhat.
  • Nonstop airflow could clog your air filter up more quickly, increasing the frequency you will want to replace it.

Which Setting for My Thermostat? Fan or Auto in Summer/Winter

Through the summer, warm air may stick around in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system may pull this warm air into the rest of your home, forcing the HVAC system to run longer to maintain the preferred temperature. In extreme heat, this may result in needing AC repair more quickly as wear and tear gets worse.

The opposite can happen 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. Leaving the fan running may pump more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should use 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 might work for you if:

Someone in your household deals with allergies. Allergies and other 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 deals with hot and cold spots. All kinds 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 can help minimize these changes by consistently refreshing each room’s ventilation.