Once the weather begins to cool off, you might be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills can contribute a large chunk of your monthly electric bill. To figure out new ways to lower their HVAC bill, some owners look closely at their thermostat. Is there a setting they should use to boost efficiency?

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what will the fan setting offer for an HVAC system? This guide will help. We’ll walk through precisely what the fan setting is and when you can use it to reduce costs during the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting indicates that the HVAC blower fan stays on. Certain furnaces may continue to generate heat at a low level in this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will run the fan over a heating or cooling cycle and switch it off once the cycle is over.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in each room more uniform by allowing the fan to keep generating airflow.
  • Indoor air quality can increase as constant airflow will keep passing airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the system’s fan helps expand its life span. Because the air handler is usually a component of the furnace, this means you might minimize the risk of needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A nonstop fan can raise your energy costs somewhat.
  • 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

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 can gradually move this warm air into the rest of your home, pushing the HVAC system to run longer to preserve the set temperature. In extreme heat, this may lead to needing AC repair more regularly as wear and tear gets worse.

The reverse can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running could draw more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to decide if you should switch to the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on may be best for you if:

Someone in your household deals with allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Lots of homes deal with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help lessen these changes by consistently refreshing each room’s supply of air.