When the weather is cooling off, you may be concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills frequently add up to a significant chunk of your monthly electric bill. To learn new ways to reduce costs, some homeowners look closely at their thermostat. Could there be a setting they could use to boost efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what will the fan setting provide for the HVAC system? This guide can help. We’ll review what exactly the fan setting is and whether you can use it to reduce costs over the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the majority of thermostats, the fan setting signifies that the HVAC blower fan keeps running. Some furnaces can run at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will start the fan during a heating or cooling cycle and switch it off after the cycle is complete.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more balanced by allowing the fan to keep running.
  • Indoor air quality will be highest because constant airflow will keep passing airborne particles through the air filter.
  • Fewer start-stop cycles for the blower fan helps expand its life span. Since the air handler is usually connected to the furnace, this means you can minimize the risk of needing furnace repair.

Disadvantages to using the Fan/On setting:

  • A nonstop fan will likely increase your energy expenses somewhat.
  • Continuous airflow could clog your air filter in a shorter amount of time, 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 will sometimes linger 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, pushing the HVAC system to work harder to preserve the set temperature. In severe heat, this may result in needing AC repair more often as wear and tear grows.

The opposite can occur in the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually drift into the rest of your home. Keeping the fan on will sometimes pump more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to decide if you should use the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may be best for you if:

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

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