Once the weather begins to cool off, you are probably wondering about how you’ll prepare your heating and cooling. After all, HVAC costs can add up to a significant piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some homeowners take a closer look at their thermostat. Could there be a setting they can use to boost efficiency?

The bulk of thermostats have 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 whether you can use it to reduce costs in the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For most thermostats, the fan setting means that the HVAC blower fan keeps running. A few furnaces may continue to operate at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will run the fan through a heating or cooling cycle and turn it off when the cycle is over.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more consistent by enabling the fan to keep circulating air.
  • Indoor air quality will be highest because continuous airflow will keep forcing airborne particles through the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps extend its life span. As the air handler is usually connected to the furnace, this means you could avoid needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A nonstop fan can add to your energy costs somewhat.
  • Nonstop airflow may clog your air filter up more quickly, 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

In the summer, warm air will sometimes linger in unfinished spaces like the attic or an attached garage. If you keep the fan running, your HVAC system might pull this warm air into the rest of your home, pushing the HVAC system to work harder to preserve the preferred temperature. In serious heat, this may result in needing AC repair more quickly as wear and tear increases.

The reverse can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running may pump more cold air upward, increasing the amount of heating you need to keep 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 are not the same. Leaving the HVAC system’s fan on might be ideal for you if:

Someone in your household deals with allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on should help to enhance indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Many homes deal with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help minimize these changes by consistently refreshing each room’s ventilation.