Once the weather starts to cool off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC bills routinely add up to a significant piece 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 can use to increase efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what will the fan setting provide for your HVAC system? This guide should help. We’ll walk through precisely what the fan setting is and how you can use it to cut costs during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting means that the HVAC blower fan stays on. A few furnaces may continue to generate heat at a low level in this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will run the fan over a heating or cooling cycle and shut it off after the cycle is over.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more consistent by enabling the fan to keep circulating air.
  • Indoor air quality should improve because continuous airflow will keep moving airborne contaminants into the air filter.
  • Fewer start-stop cycles for the system’s fan helps expand its life span. Since the air handler is often a component of the furnace, this means you could minimize the risk of needing furnace repair.

Disadvantages to using the Fan/On setting:

  • A nonstop fan could raise your energy bills slightly.
  • Nonstop 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 Summer/Winter

During the summer, warm air can persist in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system might draw this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the desired temperature. In extreme heat, this may lead to needing AC repair more quickly as wear and tear gets worse.

The opposite can take place over 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 draw 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 has allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on can help to improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Lots of homes deal with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help limit these changes by steadily refreshing each room’s airflow.