Once the weather begins to cool off, you might be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses can contribute a big portion of your monthly electric bill. To figure out new ways to lower their HVAC bill, some people look closer at their thermostat. Maybe there’s a setting they should use to increase efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what can the fan setting provide for the HVAC system? This guide can help. We’ll review just what the fan setting is and whether you can use it to save money during the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the air handler’s blower fan keeps running. Some furnaces will run at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan during a heating or cooling cycle and turn it off after the cycle is finished.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more uniform by enabling the fan to keep running.
  • 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 lengthen its life span. Since the air handler is usually a component of the furnace, this means you could minimize the risk of needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A continuous fan will likely increase your energy expenses by a small margin.
  • Nonstop airflow could clog your air filter in a shorter amount of time, increasing the frequency you should replace it.

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

In the summer, warm air will sometimes stick around in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system may pull this warm air into the rest of your home, pushing the HVAC system to run longer to keep up with the preferred temperature. In serious heat, this may result in needing AC repair more quickly as wear and tear gets worse.

The opposite can occur in 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 remain warm.

If you’re still trying to decide if you should switch to the fan/on setting, don’t forget that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on might be ideal 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 should help to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. All kinds of homes wrestle with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help minimize these changes by steadily refreshing each room’s airflow.