As the weather starts to cool off, you are probably thinking about how you’ll make the most of your heating and cooling. After all, HVAC costs can make up a big portion of your monthly electric bill. To try and find ways to save, some homeowners look closely at their thermostat. Maybe there’s a setting they could use to improve efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what will the fan setting offer for an HVAC system? This guide will help. We’ll walk through what exactly the fan setting is and whether you can use it to reduce costs during the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the majority of thermostats, the fan setting means that the system’s blower fan remains on. A few furnaces may continue to generate heat at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, on the other hand, will run the fan over a heating or cooling cycle and shut it off when the cycle is over.

There are benefits and drawbacks 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 trying the Fan/On setting:

  • You can keep the temperature throughout your home more consistent by allowing the fan to keep running.
  • Indoor air quality should improve because constant airflow will keep passing airborne particles through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is usually a component of the furnace, this means you can minimize the risk of needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A constant fan could increase your energy expenses by a small margin.
  • Nonstop airflow may clog your air filter soon, increasing the frequency you will want to replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

Through the summer, warm air will sometimes persist in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system can draw this warm air into the rest of your home, pushing the HVAC system to work more to preserve the set temperature. In severe heat, this could result in needing AC repair more often as wear and tear grows.

The reverse can occur in the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Leaving the fan setting on may pull more cold air upward, increasing the amount of heating you need to stay 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 work for you if:

Someone in your household has allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on can help to increase indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Lots of homes wrestle with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting might help limit these changes by consistently refreshing each room’s ventilation.