I'm pretty sure the Kinect has an IR light built in. So it provides it's own light for outline tracking (I'm guessing it can also read the heart rate info in the IR range). Only the color over-lay needs light in the room.

Still, I've grown to hate motion gaming, and won't be bothering with it any more.

Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris