Sensi has two different fan modes (On or Auto), and a circulating fan feature. You can toggle these features from the thermostat itself or through the Sensi app.
Fan Mode Settings
On
At the thermostat or in the Sensi app, press the Fan button to toggle the Fan On. In this mode, your blower fan will run continuously all day.
Auto
At the thermostat or in the Sensi app, press the Fan button to toggle the Fan Auto. In this mode, your blower fan will only come on when the system needs to utilize it.
Example: Your A/C comes on and the thermostat will run the fan at the same time as the outdoor unit to blow cool air through your home.
Circulating Fan
The Circulating Fan feature allows you to set a percentage of time that your blower fan will run independently throughout the day. Learn more about the circulating fan feature here.