When the weather begins to cool off, you may be thinking about how you’ll make the most of your heating and cooling. After all, HVAC costs routinely make up a big chunk of your monthly electric bill. To figure out new ways to reduce costs, some people take a closer look at their thermostat. Is there a setting they should use to improve efficiency?

The majority of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what will the fan setting provide for your HVAC system? This guide will help. We’ll walk through what exactly the fan setting is and when you can use it to save money over the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the majority of thermostats, the fan setting means that the air handler’s blower fan keeps running. Some furnaces may continue to generate heat at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will turn on the fan over a heating or cooling cycle and switch it off when the cycle is complete.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more balanced by permitting the fan to keep circulating air.
  • Indoor air quality should improve because constant airflow will keep forcing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the system’s fan helps extend its life span. As the air handler is usually a component of the furnace, this means you might prevent the need for furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A nonstop fan could raise your energy costs somewhat.
  • Nonstop airflow could 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

During the summer, warm air can linger in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system can draw this warm air into the rest of your home, pushing the HVAC system to work more to keep up with the set temperature. In extreme heat, this could lead to needing AC repair more often as wear and tear grows.

The opposite can take place over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually drift into the rest of your home. Leaving the fan running will sometimes pull more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should switch to the fan/on setting, don’t forget 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 has allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on is more likely to increase indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Lots 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 limit these changes by steadily refreshing each room’s supply of air.