Once the weather begins to cool off, you are probably concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC bills can add up to a large piece of your monthly electric bill. To try and find ways to reduce costs, some homeowners look closer at their thermostat. Is there a setting they could use to improve efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what can the fan setting provide for an HVAC system? This guide should help. We’ll share precisely what the fan setting is and whether you can use it to reduce costs in the summer or winter.

My Thermostat Has a Fan Setting?

For the bulk of thermostats, the fan setting signifies that the air handler’s blower fan remains on. Some furnaces can run at a low level with this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will start the fan through a heating or cooling cycle and turn it off after the cycle is complete.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature in every room more consistent by enabling the fan to keep generating airflow.
  • Indoor air quality can increase because steady airflow will keep forcing airborne contaminants through the air filter.
  • A smaller number of start-stop cycles for the blower fan helps expand its life span. Because the air handler is usually a component of the furnace, this means you could minimize the risk of needing furnace repair.

Drawbacks to utilizing the Fan/On setting:

  • A continuous fan will likely increase your energy expenses somewhat.
  • Continuous 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 can draw this warm air into the rest of your home, pushing the HVAC system to work more to maintain the set temperature. In severe heat, this may lead to needing AC repair more often as wear and tear gets worse.

The reverse can happen over 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. Keeping the fan on may pull more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to determine if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs will vary. Leaving the HVAC system’s fan on could work for you if:

Someone in your household has allergies. Allergies and similar respiratory conditions can be hard on the family. Leaving the fan on can help to improve indoor air quality, helping your family breathe easier.

Your home deals with 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 steadily refreshing each room’s supply of air.