When the weather begins to cool off, you might be concerned about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely contribute a big portion of your monthly electric bill. To learn new ways to lower their HVAC bill, some owners look closely at their thermostat. Could there be a setting they can use to improve efficiency?
The majority of thermostats include both a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what will the fan setting offer for an HVAC system? This guide should help. We’ll review what exactly the fan setting is and how you can use it to cut costs over 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. Some furnaces can operate at a low level with 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 shut it off when the cycle is finished.
There are benefits and drawbacks to switching on the fan setting on your thermostat, and what's ideal can depend on your personal comfort preferences.
Advantages to trying the Fan/On setting:
- You can keep the temperature throughout your home more uniform by permitting the fan to keep generating airflow.
- Indoor air quality can increase because constant airflow will keep moving airborne particles through the air filter.
- A smaller number of start-stop cycles for the system's fan helps expand its life span. As the air handler is typically connected to the furnace, this means you can minimize the risk of needing furnace repair.
Downsides to using the Fan/On setting:
- A constant fan can increase your energy costs slightly.
- Nonstop airflow can clog your air filter soon, increasing the frequency you should replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
In the summer, warm air may stick around in unfinished spaces including 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 work harder to preserve the desired temperature. In extreme heat, this may result in needing AC repair more quickly as wear and tear increases.
The opposite can occur during the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually flow into the rest of your home. Leaving the fan running will sometimes pump more cold air upward, increasing the amount of heating you need to keep 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 will vary. Leaving the HVAC system’s fan on may be best for you if:
Someone in your household has allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on is more likely to enhance indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. All kinds of homes wrestle with persistent hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help minimize these changes by constantly refreshing each room’s airflow.