Once the weather begins to cool off, you are probably concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills can add up to a significant piece of your monthly electric bill. To figure out new ways to lower their HVAC bill, some homeowners look closely at their thermostat. Is there a setting they should use to increase efficiency?

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

Should I Use My Thermostat's Fan Setting?

For the bulk of thermostats, the fan setting indicates that the air handler’s blower fan keeps running. Some furnaces can run at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will turn on the fan during a heating or cooling cycle and switch it off after the cycle is finished.

There are benefits and drawbacks to trying the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your unique comfort needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more balanced by enabling the fan to keep running.
  • Indoor air quality should improve as constant airflow will keep moving airborne pollutants through the air filter.
  • A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. Since the air handler is typically part of the furnace, this means you might minimize the risk of needing furnace repair.

Disadvantages to utilizing the Fan/On setting:

  • A continuous fan could raise your energy bills by a small margin.
  • Nonstop 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 Summer/Winter

During the summer, warm air will sometimes linger in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system might draw this warm air into the rest of your home, pushing the HVAC system to work more to maintain the set temperature. In extreme heat, this can result in needing AC repair more often as wear and tear gets worse.

The opposite can happen over the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually drift into the rest of your home. Keeping the fan on may draw 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 switch to the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could work 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 wrestle with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help lessen these changes by steadily refreshing each room’s supply of air.