Once the weather starts to cool off, you may be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills routinely add up to a significant portion of your monthly electric bill. To try and find ways to lower their HVAC bill, some owners look closer at their thermostat. Could there be a setting they should use to boost efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what does the fan setting provide for the HVAC system? This guide can help. We’ll walk through precisely what the fan setting is and when you can use it to save money over the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting means that the system’s blower fan keeps running. Some furnaces may continue to operate at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will turn on the fan over a heating or cooling cycle and shut it off once the cycle is finished.

There are benefits and drawbacks to switching on the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your unique comfort needs.

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more uniform by allowing the fan to keep circulating air.
  • Indoor air quality should improve as constant airflow will keep moving airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. Because the air handler is usually part of the furnace, this means you might avoid needing furnace repair.

Disadvantages to switching to the Fan/On setting:

  • A nonstop fan will likely add to your energy expenses by a small margin.
  • Constant airflow may clog your air filter up more quickly, increasing the frequency you will want 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 may persist in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system might pull this warm air into the rest of your home, compelling the HVAC system to work more to preserve the set temperature. In severe heat, this can lead to needing AC repair more regularly as wear and tear increases.

The reverse can occur in 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 may pull more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to figure out if you should try the fan/on setting, don’t forget that every home and family’s comfort needs will vary. 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 can help to improve indoor air quality, helping your family breathe easier.

Your home has 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 steadily refreshing each room’s airflow.