As the weather starts to cool off, you may be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses frequently add up to a big piece of your monthly electric bill. To learn new ways to save, some homeowners take a closer look at their thermostat. Maybe there’s a setting they could use to increase efficiency?

The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what can the fan setting provide for your HVAC system? This guide will help. We’ll review just what the fan setting is and whether you can use it to save money during the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting signifies that the system's blower fan stays on. Certain furnaces will operate at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will turn on the fan through a heating or cooling cycle and switch it off when the cycle is over.

There are pros and cons to switching on the fan setting on your thermostat, and the ideal option {will|can|should]] depend on your personal comfort preferences.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature throughout your home more balanced by enabling the fan to keep running.
  • Indoor air quality will be highest as constant airflow will keep passing airborne contaminants into the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is typically part of the furnace, this means you might prevent the need for furnace repair.

Drawbacks to using the Fan/On setting:

  • A continuous fan can add to your energy expenses somewhat.
  • Constant airflow could clog your air filter soon, increasing the frequency you’ll need to replace it.

Should My Thermostat Be on Fan or Auto in Summer/Winter

In the summer, warm air can linger in unfinished spaces including the attic or an attached garage. If you keep the fan running, your HVAC system may gradually move this warm air into the rest of your home, forcing the HVAC system to work more to maintain the set temperature. In serious heat, this may lead to needing AC repair more quickly as wear and tear gets worse.

The opposite can happen during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually flow 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 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 could be ideal for you if:

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

Your home experiences hot and cold spots. All kinds of homes deal with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help limit these changes by constantly refreshing each room’s ventilation.