As the weather starts to cool off, you might be wondering about how you’ll take full advantage of your heating and cooling. After all, HVAC costs frequently contribute a large piece of your monthly electric bill. To try and find ways to save, some people take a closer look at their thermostat. Is there a setting they can use to improve efficiency?
The bulk of thermostats have a ‘Fan’ or ‘Fan On’ setting. But if the fan is on during a typical cycle, what can the fan setting provide for the HVAC system? This guide can help. We’ll walk through what exactly 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 most thermostats, the fan setting means that the air handler’s blower fan stays on. Some furnaces may continue to generate heat 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 turn it off after the cycle is finished.
There are benefits and drawbacks to using the fan setting on your thermostat, and the ideal option can depend on your personal comfort needs.
Advantages to switching to the Fan/On setting:
- You can keep the temperature in every room more uniform by enabling the fan to keep generating airflow.
- Indoor air quality can increase as constant airflow will keep forcing airborne particles into the air filter.
- A smaller amount of start-stop cycles for the HVAC fan helps lengthen its life span. As the air handler is usually part of the furnace, this means you can avoid needing furnace repair.
Drawbacks to using the Fan/On setting:
- A constant fan can increase your energy costs somewhat.
- Nonstop airflow could clog your air filter up more quickly, increasing the frequency you will want to replace it.
Should My Thermostat Be on Fan or Auto in Summer/Winter
During the summer, warm air can stick around in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system may draw this warm air into the rest of your home, forcing the HVAC system to work harder to maintain the set temperature. In extreme heat, this could lead to needing AC repair more often as wear and tear increases.
The reverse can occur in the winter. Cooler spaces such as a basement will hold onto cooler air, which can eventually drift 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 keep warm.
If you’re still trying to decide if you should use the fan/on setting, don’t forget that every home and family’s comfort needs are not the same. Leaving the HVAC system’s fan on might be best for you if:
Someone in your household has allergies. Allergies and other respiratory conditions can be stressful on the family. Leaving the fan on is more likely to improve indoor air quality, helping your family breathe easier.
Your home deals with hot and cold spots. Lots of homes wrestle with persistent hot and cold spots that quickly evolve to a temperature different from the rest of the house. The fan setting might help limit these changes by constantly refreshing each room’s airflow.