As the weather begins to cool off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC expenses routinely add up to a big piece of your monthly electric bill. To figure out new ways to save, some people take a closer look at their thermostat. Maybe there’s a setting they should use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what can the fan setting provide for your HVAC system? This guide should help. We’ll review just what the fan setting is and when you can use it to save money during the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the bulk of thermostats, the fan setting means that the HVAC blower fan remains on. Certain furnaces will generate heat at a low level with this setting, but in most cases heating or cooling isn’t being made. 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 benefits and drawbacks to using the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your distinct comfort preferences.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more consistent by permitting the fan to keep running.
  • Indoor air quality will be highest since steady airflow will keep forcing airborne particles through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps extend its life span. As the air handler is typically part of the furnace, this means you can minimize the risk of needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A continuous fan will likely raise your energy bills slightly.
  • Nonstop airflow could clog your air filter soon, increasing the frequency you should replace it.

Which Setting for My Thermostat? Fan or Auto in Each Season

In the summer, warm air will sometimes persist in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system can pull this warm air into the rest of your home, compelling the HVAC system to work more to preserve the set temperature. In extreme heat, this can lead to needing AC repair more often as wear and tear increases.

The reverse can happen during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Leaving the fan running will sometimes pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to determine if you should use the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may work for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on should 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 persistent 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 steadily refreshing each room’s airflow.