Once the weather is cooling off, you might be wondering about how you’ll prepare your heating and cooling. After all, HVAC costs frequently make up a significant chunk of your monthly electric bill. To try and find ways to reduce costs, some owners look closer at their thermostat. Is there a setting they can use to increase efficiency?

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

Should I Use My Thermostat’s Fan Setting?

For most thermostats, the fan setting means that the HVAC blower fan keeps running. Some furnaces may continue to operate at a low level in this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will run the fan through a heating or cooling cycle and switch it off when 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 needs.

Advantages to switching to 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 because constant airflow will keep forcing airborne contaminants into the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps extend its life span. Since the air handler is often part of the furnace, this means you might avoid needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A nonstop fan can add to your energy expenses by a small margin.
  • 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

Through the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, pushing the HVAC system to run longer to maintain the preferred temperature. In extreme heat, this may result in needing AC repair more regularly as wear and tear increases.

The opposite can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan setting on may pump 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 switch to the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be best for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be hard 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. Lots of homes wrestle with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help limit these changes by steadily refreshing each room’s airflow.