Once the weather is cooling off, you might be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC costs routinely make up a large chunk of your monthly electric bill. To try and find ways to save, some people look closely at their thermostat. Is there a setting they could use to improve efficiency?

The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what does the fan setting provide for the HVAC system? This guide should help. We’ll share precisely what the fan setting is and when you can use it to cut costs in the summer or winter.

How Do I Access the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting means that the air handler’s blower fan remains on. A few furnaces can operate at a low level with this setting, but for the most part heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will run the fan through a heating or cooling cycle and switch it off when the cycle is complete.

There are advantages and disadvantages to using the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your personal comfort requirements.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more consistent by allowing the fan to keep generating airflow.
  • Indoor air quality should improve because continuous airflow will keep passing airborne contaminants into the air filter.
  • Fewer start-stop cycles for the blower fan helps expand its life span. Because the air handler is often part of the furnace, this means you could prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A continuous fan will likely add to your energy costs somewhat.
  • Continuous airflow could clog your air filter soon, 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 can linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system might gradually move this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the set temperature. In extreme heat, this could lead to needing AC repair more often as wear and tear gets worse.

The opposite can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually flow into the rest of your home. Leaving the fan running could 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 switch to the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could 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 deals with hot and cold spots. Many homes deal with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting should help lessen these changes by steadily refreshing each room’s ventilation.