Once the weather is cooling off, you are probably concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills frequently make up a significant chunk of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners take a closer look at their thermostat. Maybe there’s a setting they can use to improve efficiency?

Most thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what does the fan setting provide for your HVAC system? This guide can help. We’ll share just what the fan setting is and how you can use it to reduce costs during the summer or winter.

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting means that the system’s blower fan stays on. Some furnaces can operate at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will run the fan during a heating or cooling cycle and switch it off once the cycle is over.

There are benefits and drawbacks to trying the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your unique comfort needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more consistent by permitting the fan to keep running.
  • Indoor air quality will be highest since steady airflow will keep moving airborne pollutants into the air filter.
  • A smaller number of start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is usually part of the furnace, this means you can prevent the need for furnace repair.

Downsides to using the Fan/On setting:

  • A constant fan can add to your energy costs by a small margin.
  • Continuous airflow can clog your air filter soon, increasing the frequency you will want to replace it.

Which Setting for My Thermostat? Fan or Auto in Summer/Winter

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

The opposite can take place over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually drift into the rest of your home. Leaving the fan running may pull 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 are different. Leaving the HVAC system’s fan on could be ideal for you if:

Someone in your household suffers from allergies. Allergies and similar 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 has 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 supply of air.