Once the weather is cooling off, you are probably thinking about how you’ll make the most of your heating and cooling. After all, HVAC costs frequently contribute a big piece of your monthly electric bill. To try and find ways to reduce costs, some people look closely at their thermostat. Is there a setting they can use to boost efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what does the fan setting provide for an HVAC system? This guide should help. We’ll walk through what exactly the fan setting is and how you can use it to reduce costs over the summer or winter.

Should I Use My Thermostat's Fan Setting?

For the bulk of thermostats, the fan setting indicates that the HVAC blower fan keeps running. A few furnaces will operate at a low level in this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will run the fan over a heating or cooling cycle and switch it off when the cycle is complete.

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

Advantages to trying the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by enabling the fan to keep circulating air.
  • Indoor air quality will be highest since steady airflow will keep forcing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the blower fan helps extend its life span. Because the air handler is typically a component of the furnace, this means you can avoid needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A nonstop fan can add to your energy expenses slightly.
  • Constant airflow could clog your air filter in a shorter amount of time, 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 Each Season

During the summer, warm air can linger in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system can draw this warm air into the rest of your home, forcing the HVAC system to work more to maintain the desired temperature. In extreme heat, this can result in needing AC repair more regularly as wear and tear grows.

The reverse can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Keeping the fan on will sometimes draw more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to figure out if you should try the fan/on setting, don’t forget that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may work for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on is more likely to improve 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 minimize these changes by constantly refreshing each room’s airflow.