A:Answer Hello snowjob,
Good question! Ring battery products “see” the world through a network of three linked passive infrared (PIR) sensors. These are heat sensors that detect motion by monitoring heat within the detection area. Since people are hotter than the surrounding areas, as a person enters the detection area, the heat measurements change. The motion sensors register this change as movement and send out an alert. Windows generally block heat sources. Since the Ring device uses PIR (Passive Infrared) to detect motion, the Ring device will not be able to detect the motion very well through a window.
Here is a helpful article to review before purchasing: https://support.ring.com/hc/en-us/articles/360022650691-Motion-Detection-in-Ring-Battery-Devices
For further questions or support, please visit: https://community.ring.com/.
Thank you,
Alexis with Ring