Once the weather starts to cool off, you might be concerned about how you’ll take full advantage of your heating and cooling. After all, HVAC expenses routinely add up to a significant piece of your monthly electric bill. To try and find ways to save, some people look closely at their thermostat. Could there be a setting they can use to boost efficiency?
Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what can the fan setting provide for the HVAC system? This guide will help. We’ll walk through just what the fan setting is and whether you can use it to save money over the summer or winter.
What Is the Fan Setting on My Thermostat?
For the majority of thermostats, the fan setting indicates that the system's blower fan keeps running. 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, in contrast, will run the fan over a heating or cooling cycle and turn it off after the cycle is complete.
There are pros and cons to switching on the fan setting on your thermostat, and the ideal option can depend on your unique comfort preferences.
Advantages to utilizing the Fan/On setting:
- You can keep the temperature in each room more uniform by permitting the fan to keep circulating air.
- Indoor air quality should improve as constant airflow will keep forcing airborne particles through the air filter.
- Fewer start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is typically part of the furnace, this means you could minimize the risk of needing furnace repair.
Downsides to switching to the Fan/On setting:
- A constant fan could add to your energy expenses by a small margin.
- Continuous airflow may 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
Through the summer, warm air will sometimes persist in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system may draw this warm air into the rest of your home, forcing the HVAC system to run longer to maintain the set temperature. In serious heat, this may result in needing AC repair more often as wear and tear gets worse.
The opposite can take place in the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually flow into the rest of your home. Keeping the fan on could pump more cold air upward, increasing the amount of heating you need to keep warm.
If you’re still trying to determine if you should try the fan/on setting, keep in mind 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 has allergies. Allergies and other respiratory conditions can be tough on the family. Leaving the fan on can help to increase indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. Many homes wrestle with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help minimize these changes by constantly refreshing each room’s ventilation.