Once the weather begins to cool off, you might be wondering about how you’ll make the most of your heating and cooling. After all, HVAC bills can make up a significant piece of your monthly electric bill. To figure out new ways to reduce costs, some owners look closer at their thermostat. Maybe there’s a setting they can use to increase efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what will the fan setting offer for your HVAC system? This guide can help. We’ll review just what the fan setting is and when 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 signifies that the air handler’s blower fan keeps running. Some furnaces may continue to run at a low level with this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will run the fan during a heating or cooling cycle and switch it off once the cycle is over.

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 needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more balanced by enabling the fan to keep circulating air.
  • Indoor air quality will be highest as steady airflow will keep moving airborne particles 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 can minimize the risk of needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A nonstop fan could raise your energy bills by a small margin.
  • Constant 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 such as the attic or an attached garage. If you use the fan setting, your HVAC system might gradually move this warm air into the rest of your home, forcing the HVAC system to work harder to preserve the preferred temperature. In severe heat, this could result in needing AC repair more regularly as wear and tear gets worse.

The opposite can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually flow into the rest of your home. Keeping the fan on could draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should use the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be ideal for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be stressful 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. Many homes wrestle with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help lessen these changes by constantly refreshing each room’s ventilation.