When the weather begins to cool off, you may be concerned about how you’ll prepare your heating and cooling. After all, HVAC expenses routinely make up a significant piece of your monthly electric bill. To figure out new ways to save, some owners take a closer look at their thermostat. Maybe there’s a setting they can use to improve efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what will the fan setting offer for your HVAC system? This guide will help. We’ll walk through just what the fan setting is and whether you can use it to reduce costs during the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the air handler’s blower fan stays on. Some furnaces can generate heat 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 start the fan over a heating or cooling cycle and shut it off once the cycle is complete.

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

Advantages to using 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 should improve because continuous airflow will keep forcing airborne contaminants into the air filter.
  • Fewer start-stop cycles for the HVAC fan helps expand its life span. Because the air handler is typically connected to the furnace, this means you could avoid needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A constant fan can add to your energy bills by a small margin.
  • Continuous airflow may clog your air filter up more quickly, increasing the frequency you will want to replace it.

Should My Thermostat Be on? Fan or Auto in Each Season

In the summer, warm air will sometimes persist in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system can gradually move this warm air into the rest of your home, pushing the HVAC system to work more to maintain the set temperature. In serious heat, this may result in needing AC repair more often as wear and tear increases.

The reverse can happen during the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on could pump more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should try 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 best for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be tough on the family. Leaving the fan on is more likely to enhance indoor air quality, helping your family breathe easier.

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