Once the weather starts to cool off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses can add up to a big piece of your monthly electric bill. To try and find ways to reduce costs, some owners look closely at their thermostat. Maybe there’s a setting they could use to improve efficiency?

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

Should I Use My Thermostat's Fan Setting?

For most thermostats, the fan setting indicates that the system's blower fan remains on. Certain furnaces may continue to operate at a low level with this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will turn on the fan during a heating or cooling cycle and switch it off after the cycle is complete.

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

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more uniform by allowing the fan to keep running.
  • Indoor air quality can increase because constant airflow will keep forcing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the HVAC fan helps lengthen its life span. Since the air handler is typically connected to the furnace, this means you can minimize the risk of needing furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A continuous fan can increase your energy bills slightly.
  • Constant airflow can 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 Each Season

During the summer, warm air may linger in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to run longer to keep up with the preferred temperature. In serious heat, this may lead to needing AC repair more often as wear and tear gets worse.

The reverse can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually drift into the rest of your home. Keeping the fan on may 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 switch to the fan/on setting, remember that every home and family’s comfort needs are not the same. 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 hard on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help lessen these changes by constantly refreshing each room’s airflow.