Once the weather is cooling off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC costs frequently make up a large chunk of your monthly electric bill. To figure out new ways to lower their HVAC bill, some owners take a closer look at their thermostat. Maybe there’s a setting they should use to improve efficiency?

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

Should I Use My Thermostat’s Fan Setting?

For the bulk of thermostats, the fan setting means that the HVAC blower fan keeps running. A few furnaces can 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 shut it off when the cycle is finished.

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

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 will be highest as steady airflow will keep forcing airborne contaminants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps extend its life span. Because the air handler is often connected to the furnace, this means you could minimize the risk of needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A constant fan could raise your energy expenses somewhat.
  • Nonstop airflow may clog your air filter soon, 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 Summer/Winter

Through the summer, warm air can stick around in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system may draw this warm air into the rest of your home, compelling the HVAC system to work harder to maintain the desired temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear increases.

The reverse can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way 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 stay warm.

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

Someone in your household has 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 experiences hot and cold spots. Lots of homes wrestle with stubborn hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help minimize these changes by steadily refreshing each room’s airflow.