As the weather begins to cool off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC expenses can make up a large chunk of your monthly electric bill. To learn new ways to save, some owners look closer at their thermostat. Is there a setting they can use to improve efficiency?
Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a normal cycle, what does the fan setting provide for an HVAC system? This guide can help. We’ll share precisely what 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 the majority of thermostats, the fan setting signifies that the HVAC blower fan remains on. Certain furnaces will operate at a low level with this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, on the other hand, will run the fan through a heating or cooling cycle and shut it off when the cycle is over.
There are advantages and disadvantages to switching on the fan setting on your thermostat, and what's ideal can depend on your personal comfort preferences.
Advantages to using the Fan/On setting:
- You can keep the temperature in each room more consistent by allowing the fan to keep generating airflow.
- Indoor air quality will be highest since continuous airflow will keep passing airborne contaminants into the air filter.
- Fewer start-stop cycles for the system's fan helps expand its life span. As the air handler is typically part of the furnace, this means you can avoid needing furnace repair.
Downsides to utilizing the Fan/On setting:
- A continuous fan can raise your energy costs somewhat.
- Continuous airflow can clog your air filter up more quickly, 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 stick around in unfinished spaces including the attic or an attached garage. If you use the fan setting, your HVAC system may pull this warm air into the rest of your home, compelling the HVAC system to work harder to keep up with the preferred temperature. In extreme heat, this could result in needing AC repair more often as wear and tear increases.
The reverse can take place over the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Leaving the fan setting on could draw more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to decide if you should try the fan/on setting, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may work for you if:
Someone in your household deals with 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 has hot and cold spots. Many homes deal with difficult hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting can help limit these changes by constantly refreshing each room’s airflow.