Once the weather starts to cool off, you are probably concerned about how you’ll prepare your heating and cooling. After all, HVAC costs frequently make up a significant piece of your monthly electric bill. To try and find ways to lower their HVAC bill, some homeowners take a closer look at their thermostat. Could there be a setting they should use to improve efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what can the fan setting offer for an HVAC system? This guide will help. We’ll walk through precisely what the fan setting is and how you can use it to reduce costs over the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the system’s blower fan remains on. Certain furnaces can generate heat at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will run the fan over a heating or cooling cycle and turn it off once 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 distinct comfort requirements.

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in every room more balanced by allowing the fan to keep generating airflow.
  • Indoor air quality will be highest as constant airflow will keep passing airborne particles through the air filter.
  • A smaller number of start-stop cycles for the system’s fan helps extend its life span. Because the air handler is often a component of the furnace, this means you could avoid needing furnace repair.

Downsides to switching to the Fan/On setting:

  • A constant fan will likely increase your energy expenses somewhat.
  • Constant 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 Summer/Winter

Through the summer, warm air will sometimes persist in unfinished spaces including 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 more to maintain the set temperature. In extreme heat, this could result in needing AC repair more regularly as wear and tear gets worse.

The opposite can take place over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Keeping the fan on may pull more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to figure out if you should use 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 suffers from allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on can help to improve indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. All kinds 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 ventilation.