By using a built-in VOC (Volatile Organic Compounds) sensor, your thermostat measures the room air quality and shows the air quality status symbol on the local idle screen. In the mobile app, the status is indicated by text instead.
Symbol on the local idle screen
Text in the mobile app
The room air quality is good
The room air quality is okay
50% ~ 80%
The room air quality is poor
In order to ensure that the room air quality is measured accurately when the room is closed for a long time, it is recommended to force air circulation such as opening a window.