As the weather begins to cool off, you might be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC costs can add up to a big portion of your monthly electric bill. To learn new ways to save, some owners take a closer look at their thermostat. Maybe there’s a setting they could use to boost efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what can the fan setting provide for an HVAC system? This guide should help. We’ll share just what the fan setting is and when you can use it to save money in the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting means that the HVAC blower fan stays on. A few furnaces may continue to generate heat at a low level in this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will turn on the fan during a heating or cooling cycle and switch it off once the cycle is over.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more uniform by permitting the fan to keep circulating air.
  • Indoor air quality should improve since continuous airflow will keep moving airborne pollutants through the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps extend its life span. As the air handler is usually part of the furnace, this means you might prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A nonstop fan will likely increase your energy expenses by a small margin.
  • Continuous airflow could clog your air filter soon, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

Through the summer, warm air can stick around in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system might gradually move this warm air into the rest of your home, pushing the HVAC system to work harder to keep up with the set temperature. In serious heat, this may lead to needing AC repair more often as wear and tear gets worse.

The reverse can take place over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running 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 try the fan/on setting, keep in mind that every home and family’s comfort needs are different. 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 tough on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help minimize these changes by constantly refreshing each room’s supply of air.