Once the weather is cooling off, you may be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses frequently contribute a big piece of your monthly electric bill. To try and find ways to lower their HVAC bill, some homeowners look closely at their thermostat. Maybe there’s a setting they can use to boost efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what will the fan setting provide for your HVAC system? This guide should help. We’ll share precisely what the fan setting is and whether you can use it to reduce costs in the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting indicates that the air handler’s blower fan keeps running. A few furnaces will run at a low level in this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will turn on the fan through a heating or cooling cycle and shut it off after the cycle is finished.

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 every room more balanced by allowing the fan to keep running.
  • Indoor air quality will be highest as steady airflow will keep passing airborne contaminants through the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps extend its life span. Because the air handler is usually part of the furnace, this means you might minimize the risk of needing furnace repair.

Disadvantages to using the Fan/On setting:

  • A constant fan will likely increase your energy expenses somewhat.
  • Constant airflow can clog your air filter soon, 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

Through the summer, warm air can persist in unfinished spaces like 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, pushing the HVAC system to work harder to preserve the desired temperature. In extreme heat, this may result in needing AC repair more regularly as wear and tear grows.

The opposite can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan running may pull more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to decide if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on might work for you if:

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

Your home experiences hot and cold spots. All kinds 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 should help lessen these changes by constantly refreshing each room’s supply of air.