As the weather starts to cool off, you are probably thinking about how you’ll make the most of your heating and cooling. After all, HVAC costs routinely make up a big chunk of your monthly electric bill. To try and find ways to lower their HVAC bill, some people look closer at their thermostat. Maybe there’s a setting they can use to improve efficiency?
The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what can the fan setting provide for your HVAC system? This guide will help. We’ll share precisely 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 means that the system's blower fan keeps running. Certain furnaces can run at a low level with this setting, but in most cases heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will run the fan through a heating or cooling cycle and turn it off once the cycle is complete.
There are benefits and drawbacks to trying the fan setting on your thermostat, and the ideal option can depend on your unique comfort preferences.
Advantages to using the Fan/On setting:
- You can keep the temperature in every room more uniform by enabling the fan to keep circulating air.
- Indoor air quality will be highest since constant airflow will keep forcing airborne contaminants into the air filter.
- Fewer start-stop cycles for the system's fan helps extend its life span. Since the air handler is typically a component of the furnace, this means you might avoid needing furnace repair.
Disadvantages to utilizing the Fan/On setting:
- A continuous fan can add to your energy bills slightly.
- Constant airflow could clog your air filter soon, increasing the frequency you will want to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
During the summer, warm air can persist in unfinished spaces such as the attic or an attached garage. If you leave the fan on, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to run longer to maintain the preferred temperature. In serious heat, this can result in needing AC repair more quickly as wear and tear grows.
The reverse can occur in the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on may 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 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 be ideal for you if:
Someone in your household has allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on can help to enhance indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. Many homes deal with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help minimize these changes by constantly refreshing each room’s supply of air.