As the weather begins to cool off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses frequently add up to a large piece of your monthly electric bill. To try and find ways to save, some owners look closely at their thermostat. Is there a setting they could use to improve efficiency?

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

My Thermostat Has a Fan Setting?

For the majority of thermostats, the fan setting signifies that the system’s blower fan remains on. Some furnaces can generate heat at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will turn on the fan over a heating or cooling cycle and turn it off once the cycle is finished.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by allowing the fan to keep running.
  • Indoor air quality should improve since continuous airflow will keep passing airborne pollutants through the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is typically part of the furnace, this means you could avoid needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A constant fan will likely raise your energy costs by a small margin.
  • Nonstop airflow may clog your air filter up more quickly, increasing the frequency you should replace it.

Should My Thermostat Be on? Fan or Auto in Each Season

Through the summer, warm air can linger in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system might pull this warm air into the rest of your home, forcing the HVAC system to work more to preserve the set temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear increases.

The reverse can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Keeping the fan on may pull 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, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may work for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be hard 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. 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 minimize these changes by consistently refreshing each room’s ventilation.