When the weather is cooling off, you may be thinking about how you’ll prepare your heating and cooling. After all, HVAC bills routinely make up a large chunk of your monthly electric bill. To figure out new ways to save, some people look closely at their thermostat. Could there be a setting they could use to boost efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what can the fan setting provide for the HVAC system? This guide will help. We’ll review precisely what the fan setting is and how you can use it to reduce costs in the summer or winter.

What Is the Fan Setting on My Thermostat?

For the majority of thermostats, the fan setting signifies that the system’s blower fan stays on. A few furnaces can run at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will turn on the fan through a heating or cooling cycle and turn it off when the cycle is complete.

There are pros and cons to switching on the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your personal comfort preferences.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in each room more consistent by allowing the fan to keep running.
  • Indoor air quality should improve since steady airflow will keep forcing airborne pollutants into the air filter.
  • Fewer start-stop cycles for the system’s fan helps lengthen its life span. Since the air handler is often a component of the furnace, this means you can prevent the need for furnace repair.

Downsides to switching to the Fan/On setting:

  • A continuous fan will likely raise your energy bills somewhat.
  • Continuous airflow could clog your air filter up more quickly, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Each Season

In 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 may draw this warm air into the rest of your home, forcing the HVAC system to run longer to preserve the desired temperature. In severe heat, this can result in needing AC repair more often as wear and tear increases.

The opposite can happen over the winter. Cooler spaces like a basement will hold onto cooler air, which may eventually drift into the rest of your home. Leaving the fan running could pump more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to figure out 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 might 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 can help to increase indoor air quality, helping your family breathe easier.

Your home has hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help limit these changes by consistently refreshing each room’s ventilation.