When the weather starts to cool off, you may be concerned about how you’ll make the most of your heating and cooling. After all, HVAC expenses can add up to a big portion of your monthly electric bill. To try and find ways to lower their HVAC bill, some owners take a closer look at their thermostat. Is there a setting they can use to boost efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what will the fan setting offer for your HVAC system? This guide should help. We’ll share precisely what 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 indicates that the system's blower fan stays on. Certain furnaces will run at a low level in this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will turn on the fan over a heating or cooling cycle and shut it off once the cycle is complete.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature in every room more uniform by allowing the fan to keep generating airflow.
  • Indoor air quality will be highest since steady airflow will keep moving airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps expand its life span. Since the air handler is typically part of the furnace, this means you can avoid needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A constant fan will likely add to your energy costs slightly.
  • Continuous airflow could 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

In the summer, warm air may linger in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to work more to maintain the set temperature. In extreme heat, this may lead to needing AC repair more regularly as wear and tear grows.

The reverse can occur in the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Leaving the fan running could pump more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to decide if you should try the fan/on setting, remember 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 stressful on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help minimize these changes by steadily refreshing each room’s supply of air.