Once the weather is cooling off, you might be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills routinely contribute a significant piece of your monthly electric bill. To try and find ways to lower their HVAC bill, some people look closer at their thermostat. Is there a setting they could use to boost efficiency?

The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what will the fan setting provide for your HVAC system? This guide should help. We’ll walk through just what the fan setting is and when you can use it to cut costs over the summer or winter.

My Thermostat Has a Fan Setting?

For the bulk of thermostats, the fan setting indicates that the HVAC blower fan remains on. Certain furnaces can generate heat at a low level with this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan over a heating or cooling cycle and switch it off after the cycle is finished.

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 distinct comfort needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more consistent by enabling the fan to keep circulating air.
  • Indoor air quality should improve because continuous airflow will keep passing airborne particles through the air filter.
  • Fewer start-stop cycles for the blower fan helps expand its life span. Because the air handler is usually part of the furnace, this means you could minimize the risk of needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A constant fan will likely increase your energy expenses slightly.
  • Nonstop airflow may clog your air filter up more quickly, 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 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, pushing the HVAC system to work harder to maintain the desired temperature. In extreme heat, this could lead to needing AC repair more quickly as wear and tear grows.

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. Keeping the fan on may draw 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, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on might work for you if:

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

Your home has hot and cold spots. All kinds of homes deal with stubborn 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 supply of air.