When the weather begins to cool off, you may be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC bills frequently contribute a significant chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some people look closely at their thermostat. Is there a setting they can use to boost efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what will the fan setting provide for your HVAC system? This guide will help. We’ll share just what the fan setting is and how you can use it to cut costs over the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting means that the air handler’s blower fan stays on. Some furnaces may continue to operate at a low level with this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will start the fan through a heating or cooling cycle and turn it off after the cycle is finished.

There are advantages and disadvantages to trying the fan setting on your thermostat, and the ideal option {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 uniform by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest as continuous airflow will keep forcing airborne pollutants through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps extend its life span. Since the air handler is typically a component of the furnace, this means you could prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A nonstop fan will likely increase your energy bills by a small margin.
  • Nonstop airflow can clog your air filter up more quickly, increasing the frequency you should replace it.

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

During the summer, warm air will sometimes persist in unfinished spaces including 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, pushing the HVAC system to work more to preserve the set temperature. In serious heat, this can lead to needing AC repair more quickly as wear and tear increases.

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

If you’re still trying to figure out 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 might be best for you if:

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

Your home has 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 might help minimize these changes by constantly refreshing each room’s ventilation.