Once the weather begins to cool off, you may be wondering about how you’ll make the most of your heating and cooling. After all, HVAC expenses frequently make up a large portion of your monthly electric bill. To learn new ways to lower their HVAC bill, some people look closer at their thermostat. Could there be a setting they can use to boost efficiency?

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

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the system's blower fan stays on. Certain furnaces will generate heat at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan over a heating or cooling cycle and switch it off after the cycle is complete.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by allowing the fan to keep circulating air.
  • Indoor air quality will be highest since continuous airflow will keep moving airborne particles through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps expand its life span. Because the air handler is often part of the furnace, this means you might minimize the risk of needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A constant fan can raise your energy bills somewhat.
  • Constant airflow can clog your air filter up more quickly, increasing the frequency you will want to replace it.

Should My Thermostat Be on Fan or Auto in Summer/Winter

In the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system can gradually move this warm air into the rest of your home, forcing the HVAC system to work more to maintain the set temperature. In extreme heat, this may result in needing AC repair more regularly as wear and tear gets worse.

The opposite can happen in the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Keeping the fan on 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 different. Leaving the HVAC system’s fan on could be ideal for you if:

Someone in your household deals with allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Many 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 lessen these changes by constantly refreshing each room’s airflow.