As the weather starts to cool off, you may be thinking about how you’ll take full advantage of your heating and cooling. After all, HVAC costs frequently make up a big piece of your monthly electric bill. To figure out new ways to save, some homeowners take a closer look at their thermostat. Could there be a setting they can use to increase efficiency?
Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what will the fan setting offer for the HVAC system? This guide will help. We’ll share precisely what the fan setting is and how 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 air handler’s blower fan stays on. Some furnaces may continue to operate at a low level in this setting, but for the most part heating or cooling isn’t being made. The ‘Auto’ setting, on the other hand, will start the fan through a heating or cooling cycle and shut it off once the cycle is finished.
There are benefits and drawbacks to trying the fan setting on your thermostat, and the ideal option can depend on your unique comfort preferences.
Advantages to switching to the Fan/On setting:
- You can keep the temperature in each room more balanced by enabling the fan to keep running.
- Indoor air quality will be highest as continuous airflow will keep moving airborne contaminants into the air filter.
- A smaller amount of start-stop cycles for the system's fan helps lengthen its life span. Since the air handler is usually a component of the furnace, this means you could minimize the risk of needing furnace repair.
Downsides to using the Fan/On setting:
- A nonstop fan could increase your energy costs somewhat.
- Nonstop airflow may 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 leave the fan on, your HVAC system may gradually move this warm air into the rest of your home, pushing the HVAC system to run longer to maintain the set temperature. In extreme heat, this can lead to needing AC repair more often as wear and tear gets worse.
The reverse can take place 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 setting 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, remember that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on may 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 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 can help lessen these changes by constantly refreshing each room’s ventilation.