Once the weather begins to cool off, you might be wondering about how you’ll prepare your heating and cooling. After all, HVAC bills frequently make up a large portion of your monthly electric bill. To figure out new ways to lower their HVAC bill, some homeowners look closely at their thermostat. Is there a setting they could use to boost efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what can the fan setting provide for your HVAC system? This guide should help. We’ll review precisely what the fan setting is and when you can use it to cut costs in 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 keeps running. Certain furnaces may continue to run at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will start the fan during a heating or cooling cycle and switch it off after the cycle is complete.

There are benefits and drawbacks to using the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your unique comfort requirements.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by allowing the fan to keep circulating air.
  • Indoor air quality will be highest as continuous airflow will keep passing airborne particles through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps expand its life span. As the air handler is typically a component of the furnace, this means you might minimize the risk of needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan will likely raise your energy costs by a small margin.
  • Continuous 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 Each Season

In the summer, warm air may persist in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system might pull this warm air into the rest of your home, compelling the HVAC system to work harder to preserve the preferred temperature. In severe heat, this can result in needing AC repair more often as wear and tear grows.

The reverse can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan setting on will sometimes draw more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to decide if you should switch to 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 may be best for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be tough on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. All kinds of homes wrestle with difficult 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.