When the weather begins to cool off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills frequently contribute a large chunk of your monthly electric bill. To try and find ways to reduce costs, some people look closely at their thermostat. Is there a setting they should use to increase efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a regular cycle, what can the fan setting offer for your HVAC system? This guide can help. We’ll share what exactly the fan setting is and when you can use it to save money in the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For the bulk of thermostats, the fan setting signifies that the air handler’s blower fan remains on. Some furnaces will operate at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, in contrast, will turn on the fan during a heating or cooling cycle and switch it off when the cycle is complete.

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

Advantages to utilizing the Fan/On setting:

  • You can keep the temperature in each room more balanced by allowing the fan to keep running.
  • Indoor air quality will be highest as continuous airflow will keep passing airborne pollutants into the air filter.
  • A smaller number of start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is often connected to the furnace, this means you might minimize the risk of needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A continuous fan can add to your energy costs by a small margin.
  • Continuous airflow can clog your air filter in a shorter amount of time, increasing the frequency you’ll need to replace it.

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

During the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you leave the fan on, your HVAC system may gradually move this warm air into the rest of your home, forcing the HVAC system to work harder to preserve the desired temperature. In extreme heat, this may result in needing AC repair more quickly as wear and tear gets worse.

The reverse can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually make its way into the rest of your home. Leaving the fan running could 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 use 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 deals with allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on should help to increase indoor air quality, helping your family breathe easier.

Your home experiences hot and cold spots. Many homes deal with persistent hot and cold spots that quickly shift 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.