Once the weather is cooling off, you are probably thinking 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 owners take a closer look at their thermostat. Is there a setting they should use to boost efficiency?

Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a regular cycle, what can the fan setting provide for an HVAC system? This guide will help. We’ll walk through precisely what the fan setting is and when you can use it to reduce costs in the summer or winter.

What Is the Fan Setting on My Thermostat?

For most thermostats, the fan setting indicates that the HVAC blower fan keeps running. A few furnaces will generate heat at a low level in this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will turn on the fan during a heating or cooling cycle and switch it off when the cycle is over.

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

Advantages to using the Fan/On setting:

  • You can keep the temperature throughout your home more uniform by permitting the fan to keep running.
  • Indoor air quality will be highest since steady airflow will keep forcing airborne pollutants through the air filter.
  • Fewer start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is typically part of the furnace, this means you might prevent the need for furnace repair.

Disadvantages to using the Fan/On setting:

  • A continuous fan could raise your energy expenses slightly.
  • Constant 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

Through the summer, warm air may persist in unfinished spaces like the attic or an attached garage. If you leave the fan on, your HVAC system may gradually move this warm air into the rest of your home, pushing the HVAC system to run longer to keep up with the set temperature. In extreme heat, this can result in needing AC repair more quickly as wear and tear increases.

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

If you’re still trying to decide if you should switch to the fan/on setting, remember that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might work for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on should 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 shift to a temperature different from the rest of the house. The fan setting can help minimize these changes by consistently refreshing each room’s airflow.