As the weather is cooling off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC costs routinely contribute a large piece of your monthly electric bill. To try and find ways to save, some owners take a closer look at their thermostat. Could there be a setting they should use to boost efficiency?
The bulk of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what does the fan setting provide for the HVAC system? This guide should help. We’ll walk through precisely what the fan setting is and whether you can use it to cut costs over the summer or winter.
What Is the Fan Setting on My Thermostat?
For the bulk of thermostats, the fan setting signifies that the system's blower fan remains on. A few furnaces can operate at a low level in this setting, but in general heating or cooling isn’t being made. The ‘Auto’ setting, conversely, will run the fan through a heating or cooling cycle and turn it off after the cycle is complete.
There are advantages and disadvantages to using the fan setting on your thermostat, and what's ideal will depend on your unique comfort requirements.
Advantages to trying the Fan/On setting:
- You can keep the temperature in every room more balanced by enabling the fan to keep generating airflow.
- Indoor air quality should improve as steady airflow will keep moving airborne pollutants through the air filter.
- Fewer start-stop cycles for the system's fan helps extend its life span. Because the air handler is often a component of the furnace, this means you can avoid needing furnace repair.
Drawbacks to using the Fan/On setting:
- A constant fan will likely add to your energy costs somewhat.
- Constant airflow could clog your air filter in a shorter amount of time, increasing the frequency you should 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 might 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 could result in needing AC repair more often as wear and tear grows.
The opposite can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Keeping the fan on may pump more cold air upward, increasing the amount of heating you need to stay warm.
If you’re still trying to determine if you should try the fan/on setting, don’t forget that every home and family’s comfort needs will vary. 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 tough 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 difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help lessen these changes by constantly refreshing each room’s supply of air.