As the weather is cooling off, you may be thinking about how you’ll prepare your heating and cooling. After all, HVAC bills routinely contribute a large portion of your monthly electric bill. To try and find ways to save, some owners look closer at their thermostat. Maybe there’s a setting they could use to boost 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 will help. We’ll share just what the fan setting is and when you can use it to cut costs in 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 will run at a low level with this setting, but in most cases heating or cooling isn’t being produced. The ‘Auto’ setting, conversely, will turn on the fan over a heating or cooling cycle and turn it off when the cycle is complete.
There are pros and cons to switching on the fan setting on your thermostat, and whether you do or don’t can depend on your distinct comfort preferences.
Advantages to trying the Fan/On setting:
- You can keep the temperature in every room more balanced by enabling the fan to keep generating airflow.
- Indoor air quality will be highest because continuous airflow will keep forcing airborne particles into the air filter.
- A smaller number of start-stop cycles for the HVAC fan helps extend its life span. Since the air handler is typically connected to the furnace, this means you can prevent the need for furnace repair.
Disadvantages to utilizing the Fan/On setting:
- A nonstop fan can raise your energy expenses somewhat.
- Nonstop airflow may clog your air filter in a shorter amount of time, 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 may persist in unfinished spaces such as the attic or an attached garage. If you keep the fan running, your HVAC system can pull this warm air into the rest of your home, forcing the HVAC system to run longer to maintain the preferred temperature. In severe heat, this could lead to needing AC repair more quickly as wear and tear gets worse.
The reverse can take place during the winter. Cooler spaces such as a basement will hold onto cooler air, which will eventually make its way into the rest of your home. Keeping the fan on may pump 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 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 work for you if:
Someone in your household suffers from allergies. Allergies and similar respiratory conditions can be stressful on the family. Leaving the fan on should help to improve indoor air quality, helping your family breathe easier.
Your home has hot and cold spots. Many homes wrestle with stubborn hot and cold spots that quickly shift to a temperature different from the rest of the house. The fan setting should help lessen these changes by steadily refreshing each room’s supply of air.