When the weather begins to cool off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC bills can contribute a big piece of your monthly electric bill. To try and find ways to reduce costs, some people look closely at their thermostat. Could there be a setting they should use to improve efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what does the fan setting provide for an 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 means that the air handler’s blower fan keeps running. Certain furnaces can generate heat at a low level with this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will run the fan over a heating or cooling cycle and turn it off when the cycle is complete.

There are benefits and drawbacks to switching on the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your personal comfort needs.

Advantages to switching to the Fan/On setting:

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

Downsides to utilizing the Fan/On setting:

  • A constant fan could increase your energy bills slightly.
  • Nonstop airflow could clog your air filter soon, increasing the frequency you should 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 persist in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system can draw this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the desired temperature. In serious heat, this may result in needing AC repair more quickly as wear and tear increases.

The reverse can happen over 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 could pump more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to determine if you should try the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could be best for you if:

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

Your home deals with hot and cold spots. Many homes wrestle with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help minimize these changes by constantly refreshing each room’s airflow.