As the weather is cooling off, you are probably thinking about how you’ll prepare your heating and cooling. After all, HVAC expenses frequently make up a large piece of your monthly electric bill. To learn new ways to save, some people take a closer look at their thermostat. Maybe there’s a setting they could use to improve efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what can the fan setting offer for an HVAC system? This guide should help. We’ll walk through just what the fan setting is and how you can use it to cut costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the system’s blower fan keeps running. Certain furnaces may continue to generate heat at a low level with this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will start the fan during a heating or cooling cycle and turn it off after the cycle is finished.

There are pros and cons 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 each room more balanced by permitting the fan to keep running.
  • Indoor air quality can increase as continuous airflow will keep moving airborne contaminants through the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is usually a component of the furnace, this means you can prevent the need for furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A nonstop fan can raise your energy bills somewhat.
  • Continuous 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 Each Season

In the summer, warm air can stick around in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system can pull this warm air into the rest of your home, compelling the HVAC system to work harder to preserve the preferred temperature. In serious heat, this may 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 setting on 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 use the fan/on setting, don’t forget that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could 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 is more likely to enhance indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Many homes deal with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help minimize these changes by steadily refreshing each room’s ventilation.