Once the weather starts to cool off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses can make up a big chunk of your monthly electric bill. To learn new ways to reduce costs, some homeowners take a closer look at their thermostat. Could there be a setting they could use to increase efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what will the fan setting provide for your HVAC system? This guide can help. We’ll walk through what exactly the fan setting is and how you can use it to cut costs during the summer or winter.

My Thermostat Has a Fan Setting?

For the bulk of thermostats, the fan setting signifies that the system’s blower fan stays on. A few furnaces may continue to operate at a low level with this setting, but for the most part heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will start the fan through a heating or cooling cycle and turn it off after the cycle is complete.

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 requirements.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more uniform by enabling the fan to keep circulating air.
  • Indoor air quality should improve because constant airflow will keep passing airborne contaminants into the air filter.
  • Fewer start-stop cycles for the HVAC fan helps lengthen its life span. Since the air handler is often part of the furnace, this means you could avoid needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A constant fan could increase your energy bills by a small margin.
  • Nonstop airflow may 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 Each Season

During the summer, warm air will sometimes stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system can draw this warm air into the rest of your home, compelling the HVAC system to work harder to preserve the desired temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear increases.

The reverse can occur over the winter. Cooler spaces like a basement will hold onto cooler air, which may 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 switch to the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on might be ideal for you if:

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

Your home experiences hot and cold spots. Many homes deal 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 steadily refreshing each room’s airflow.