Seasonal Guide: Should My Thermostat Be on Fan or Auto?

As the weather starts to cool off, you may be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses can make up a significant piece of your monthly electric bill. To figure out new ways to reduce costs, some owners take a closer look at their thermostat. Is there a setting they can use to increase efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what can the fan setting provide for the HVAC system? This guide will help. We’ll share what exactly the fan setting is and whether you can use it to save money during the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting indicates that the HVAC blower fan keeps running. Some furnaces may continue to operate at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan through a heating or cooling cycle and shut it off once the cycle is over.

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

Advantages to using the Fan/On setting:

• You can keep the temperature in each room more balanced by permitting the fan to keep running.
• Indoor air quality should improve as constant airflow will keep moving airborne particles through the air filter.
• A smaller number of start-stop cycles for the HVAC fan helps expand its life span. As the air handler is typically connected to the furnace, this means you might avoid needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

• A continuous fan can add to your energy bills somewhat.
• Constant airflow may clog your air filter in a shorter amount of time, 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

During the summer, warm air may persist in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system might draw this warm air into the rest of your home, compelling the HVAC system to work harder to keep up with the desired temperature. In severe heat, this can result in needing AC repair more often as wear and tear increases.

The opposite can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually flow into the rest of your home. Leaving the fan running will sometimes draw more cold air upward, increasing the amount of heating you need to keep warm.

If you’re still trying to figure out if you should try the fan/on setting, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on may be ideal 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 increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help minimize these changes by steadily refreshing each room’s supply of air.