As the weather is cooling off, you might be thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely make up a big chunk of your monthly electric bill. To figure out new ways to save, some people look closely at their thermostat. Maybe there’s a setting they could use to increase efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what does the fan setting offer for an HVAC system? This guide should help. We’ll review just what the fan setting is and whether you can use it to reduce costs over the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting indicates that the system’s blower fan stays on. Certain furnaces can run at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will turn on the fan over a heating or cooling cycle and shut it off after the cycle is over.

There are advantages and disadvantages to trying the fan setting on your thermostat, and what’s ideal {will|can|should]] depend on your unique comfort needs.

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more consistent by enabling the fan to keep running.
  • Indoor air quality can increase as steady airflow will keep forcing airborne contaminants through the air filter.
  • Fewer start-stop cycles for the system’s fan helps lengthen its life span. Because the air handler is typically connected to the furnace, this means you can minimize the risk of needing furnace repair.

Drawbacks to using the Fan/On setting:

  • A continuous fan could increase your energy expenses somewhat.
  • Nonstop airflow could clog your air filter up more quickly, increasing the frequency you’ll need 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 will sometimes stick around in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system might draw this warm air into the rest of your home, compelling the HVAC system to run longer to keep up with the set temperature. In severe heat, this may lead to needing AC repair more regularly as wear and tear gets worse.

The reverse can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Keeping the fan on 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 try the fan/on setting, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be best for you if:

Someone in your household has allergies. Allergies and other 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. Many homes wrestle with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help limit these changes by constantly refreshing each room’s ventilation.