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 add up to a big piece of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners look closer at their thermostat. Is there a setting they could use to boost efficiency?

The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what does the fan setting offer for your HVAC system? This guide can help. We’ll review just what the fan setting is and how you can use it to cut costs over the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting means that the system’s blower fan keeps running. A few furnaces will generate heat at a low level in this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and turn it off after the cycle is complete.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more uniform by enabling the fan to keep generating airflow.
  • Indoor air quality should improve as continuous airflow will keep forcing airborne pollutants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps expand its life span. As the air handler is usually part of the furnace, this means you might minimize the risk of needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A continuous fan could increase your energy bills by a small margin.
  • Continuous airflow could 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 Each Season

During the summer, warm air can persist in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system might draw this warm air into the rest of your home, compelling the HVAC system to run longer to maintain the desired temperature. In extreme heat, this could result in needing AC repair more often as wear and tear grows.

The reverse can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually drift into the rest of your home. Keeping the fan on will sometimes pump more cold air upward, increasing the amount of heating you need to stay warm.

If you’re still trying to determine if you should use the fan/on setting, remember that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could be best for you if:

Someone in your household has allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Many homes wrestle with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help limit these changes by constantly refreshing each room’s ventilation.