As the weather begins to cool off, you are probably thinking about how you’ll prepare your heating and cooling. After all, HVAC costs routinely contribute a large chunk of your monthly electric bill. To learn new ways to lower their HVAC bill, some homeowners look closely at their thermostat. Maybe there’s a setting they could use to increase efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what can the fan setting offer 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 over the summer or winter.

My Thermostat Has a Fan Setting?

For most thermostats, the fan setting indicates that the system's blower fan keeps running. Certain furnaces can operate at a low level in this setting, but in most cases heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will run the fan during a heating or cooling cycle and switch it off when the cycle is complete.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by permitting the fan to keep generating airflow.
  • Indoor air quality will be highest since constant airflow will keep passing airborne contaminants into the air filter.
  • Fewer start-stop cycles for the system's fan helps expand its life span. Because the air handler is typically a component of the furnace, this means you might avoid needing furnace repair.

Downsides to utilizing the Fan/On setting:

  • A nonstop fan can raise your energy costs by a small margin.
  • Constant airflow can clog your air filter in a shorter amount of time, 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

In the summer, warm air will sometimes stick around in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system can gradually move this warm air into the rest of your home, compelling the HVAC system to work more to maintain the set temperature. In severe heat, this could lead to needing AC repair more regularly as wear and tear increases.

The opposite can happen in the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually drift into the rest of your home. Keeping the fan on could pull more cold air upward, increasing the amount of heating you need to keep 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 be best for you if:

Someone in your household has allergies. Allergies and other respiratory conditions can be stressful 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. Many homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting might help minimize these changes by consistently refreshing each room’s ventilation.