When the weather starts to cool off, you are probably wondering about how you’ll prepare your heating and cooling. After all, HVAC bills can add up to a significant chunk of your monthly electric bill. To learn new ways to save, some people take a closer look at their thermostat. Is there a setting they can use to increase efficiency?
Most thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a regular cycle, what will the fan setting provide for the HVAC system? This guide should help. We’ll walk through what exactly the fan setting is and how you can use it to reduce costs over the summer or winter.
What Is the Fan Setting on My Thermostat?
For the bulk of thermostats, the fan setting means that the system's blower fan stays on. A few furnaces may continue to generate heat at a low level in this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, 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 what's ideal can depend on your distinct comfort preferences.
Advantages to trying the Fan/On setting:
- You can keep the temperature in every room more uniform by permitting the fan to keep running.
- Indoor air quality should improve since steady airflow will keep passing airborne pollutants through the air filter.
- Fewer start-stop cycles for the blower fan helps lengthen its life span. Since the air handler is often connected to the furnace, this means you can prevent the need for furnace repair.
Disadvantages to switching to the Fan/On setting:
- A nonstop fan could increase your energy expenses somewhat.
- 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
Through the summer, warm air can stick around in unfinished spaces like the attic or an attached garage. If you use the fan setting, your HVAC system may draw this warm air into the rest of your home, forcing the HVAC system to run longer to maintain the preferred temperature. In serious heat, this can lead to needing AC repair more often as wear and tear gets worse.
The reverse can occur during the winter. Cooler spaces such as a basement will hold onto cooler air, which may eventually make its way into the rest of your home. Keeping the fan on may draw more cold air upward, increasing the amount of heating you need to keep warm.
If you’re still trying to figure out if you should use the fan/on setting, keep in mind that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on might work for you if:
Someone in your household deals with allergies. Allergies and similar respiratory conditions can be tough on the family. Leaving the fan on can help to enhance indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. All kinds of homes deal with difficult hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting should help limit these changes by consistently refreshing each room’s supply of air.