As the weather is cooling off, you are probably thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC bills frequently make up a significant chunk of your monthly electric bill. To try and find ways to save, some homeowners look closely at their thermostat. Maybe there’s a setting they can use to boost efficiency?
The majority of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a normal cycle, what can the fan setting provide for the HVAC system? This guide should help. We’ll review what exactly the fan setting is and when you can use it to cut costs in the summer or winter.
What Is the Fan Setting on My Thermostat?
For the bulk of thermostats, the fan setting signifies that the HVAC blower fan remains on. Certain 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, on the other hand, will run the fan over a heating or cooling cycle and switch it off once the cycle is finished.
There are pros and cons to using the fan setting on your thermostat, and the ideal option should depend on your personal comfort needs.
Advantages to switching to the Fan/On setting:
- You can keep the temperature in every room more uniform by allowing the fan to keep running.
- Indoor air quality will be highest since steady airflow will keep moving airborne contaminants through the air filter.
- Fewer start-stop cycles for the system's fan helps lengthen its life span. As the air handler is usually part of the furnace, this means you can minimize the risk of needing furnace repair.
Downsides to using the Fan/On setting:
- A constant fan could add to your energy costs slightly.
- Continuous airflow could clog your air filter in a shorter amount of time, increasing the frequency you will want to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
Through the summer, warm air can stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system might gradually move this warm air into the rest of your home, compelling the HVAC system to run longer to preserve the preferred temperature. In serious heat, this may lead to needing AC repair more often as wear and tear increases.
The opposite can take place during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually flow into the rest of your home. Keeping the fan on will sometimes pump more cold air upward, increasing the amount of heating you need to stay warm.
If you’re still trying to decide if you should try the fan/on setting, don’t forget 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 hard on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help limit these changes by constantly refreshing each room’s ventilation.