When the weather is cooling off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC expenses can make up a large piece of your monthly electric bill. To try and find ways to reduce costs, some homeowners look closely at their thermostat. Maybe there’s a setting they can 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 provide for the HVAC system? This guide should help. We’ll share just what the fan setting is and how you can use it to cut costs over the summer or winter.

What Is the Fan Setting on My Thermostat?

For the bulk of thermostats, the fan setting means that the system’s blower fan stays on. A few furnaces can run at a low level in this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will run the fan over a heating or cooling cycle and shut it off when the cycle is complete.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature throughout your home more consistent by permitting the fan to keep running.
  • Indoor air quality can increase since continuous airflow will keep moving airborne contaminants into the air filter.
  • Fewer start-stop cycles for the system’s fan helps extend its life span. Because the air handler is typically a component of the furnace, this means you can prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A nonstop fan could add to your energy bills by a small margin.
  • Constant airflow may clog your air filter in a shorter amount of time, 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

During the summer, warm air can stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system might gradually move this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the preferred temperature. In extreme heat, this could lead to needing AC repair more regularly as wear and tear increases.

The opposite can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually drift 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 remain warm.

If you’re still trying to decide if you should try the fan/on setting, don’t forget 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 suffers from allergies. Allergies and other respiratory conditions can be stressful 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. Many homes deal with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help minimize these changes by consistently refreshing each room’s supply of air.