As the weather begins to cool off, you are probably thinking about how you’ll make the most of your heating and cooling. After all, HVAC expenses frequently contribute a large piece of your monthly electric bill. To figure out new ways to reduce costs, some people look closely at their thermostat. Maybe there’s a setting they should use to improve efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what can the fan setting offer for an HVAC system? This guide can help. We’ll share what exactly the fan setting is and when you can use it to save money in the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the HVAC blower fan remains on. Some furnaces will run at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will run the fan over a heating or cooling cycle and turn it off after the cycle is over.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more balanced by allowing the fan to keep circulating air.
  • Indoor air quality will be highest since constant airflow will keep moving airborne particles into the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps extend its life span. As the air handler is often part of the furnace, this means you can avoid needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A constant fan can increase your energy costs slightly.
  • Constant airflow can clog your air filter up more quickly, increasing the frequency you’ll need to replace it.

Should My Thermostat Be on? Fan or Auto in Summer/Winter

In the summer, warm air can persist in unfinished spaces including 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, compelling the HVAC system to work harder to maintain the desired temperature. In extreme heat, this could result in needing AC repair more often as wear and tear gets worse.

The reverse can happen during the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan running will sometimes pull 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 ideal for you if:

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

Your home has hot and cold spots. Many homes wrestle with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help minimize these changes by constantly refreshing each room’s ventilation.