Once the weather is cooling off, you may be wondering about how you’ll prepare your heating and cooling. After all, HVAC bills routinely contribute a significant piece of your monthly electric bill. To learn new ways to save, some owners look closely at their thermostat. Is there a setting they can use to increase efficiency?
Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a normal cycle, what does the fan setting provide for your HVAC system? This guide can help. We’ll share what exactly the fan setting is and when 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 air handler’s blower fan remains on. Some furnaces may continue to run at a low level in this setting, but in general heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will start the fan over a heating or cooling cycle and shut it off after the cycle is complete.
There are advantages and disadvantages to trying the fan setting on your thermostat, and what's ideal should depend on your unique comfort preferences.
Advantages to switching to the Fan/On setting:
- You can keep the temperature throughout your home more consistent by enabling the fan to keep generating airflow.
- Indoor air quality should improve since constant airflow will keep passing airborne particles through the air filter.
- A smaller amount of start-stop cycles for the blower fan helps expand its life span. As the air handler is usually connected to the furnace, this means you can minimize the risk of needing furnace repair.
Drawbacks to utilizing the Fan/On setting:
- A continuous fan could add to your energy costs somewhat.
- Nonstop airflow may clog your air filter in a shorter amount of time, increasing the frequency you will want to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
In the summer, warm air may persist in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system may gradually move this warm air into the rest of your home, forcing the HVAC system to run longer to preserve the preferred temperature. In severe heat, this may lead to needing AC repair more regularly as wear and tear increases.
The opposite can take place in the winter. Cooler spaces like a basement will hold onto cooler air, which will eventually flow into the rest of your home. Keeping the fan on could pull more cold air upward, increasing the amount of heating you need to remain warm.
If you’re still trying to determine if you should switch to 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 ideal for you if:
Someone in your household has allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on is more likely to increase indoor air quality, helping your family breathe easier.
Your home experiences hot and cold spots. All kinds of homes deal with persistent 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 steadily refreshing each room’s ventilation.