When the weather is cooling off, you may be thinking about how you’ll make the most of your heating and cooling. After all, HVAC bills routinely contribute a significant chunk of your monthly electric bill. To try and find ways to reduce costs, some homeowners take a closer look at their thermostat. Could there be a setting they should use to improve efficiency?
The bulk of thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is going during a typical cycle, what can the fan setting offer 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 during the summer or winter.
What Is the Fan Setting on My Thermostat?
For most thermostats, the fan setting signifies that the system's blower fan remains on. Some furnaces may continue to generate heat at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, in contrast, will run the fan through a heating or cooling cycle and shut it off after the cycle is complete.
There are pros and cons to trying the fan setting on your thermostat, and what's ideal {will|can|should]] depend on your unique comfort preferences.
Advantages to using the Fan/On setting:
- You can keep the temperature in each room more uniform by enabling the fan to keep running.
- Indoor air quality will be highest because steady airflow will keep forcing airborne particles through the air filter.
- A smaller amount of start-stop cycles for the HVAC fan helps extend its life span. Because the air handler is often connected to the furnace, this means you could avoid needing furnace repair.
Disadvantages to using the Fan/On setting:
- A continuous fan could raise your energy expenses slightly.
- Constant airflow could clog your air filter soon, increasing the frequency you’ll need to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
In the summer, warm air will sometimes linger in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system might draw this warm air into the rest of your home, pushing the HVAC system to run longer to preserve the desired temperature. In serious heat, this could result in needing AC repair more regularly as wear and tear increases.
The opposite can occur over 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 could draw more cold air upward, increasing the amount of heating you need to keep warm.
If you’re still trying to decide if you should switch to the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on could be best for you if:
Someone in your household deals with allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on can help to increase indoor air quality, helping your family breathe easier.
Your home experiences hot and cold spots. Many homes wrestle with difficult hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting can help limit these changes by constantly refreshing each room’s ventilation.
