Hey guys. I've tried getting a better picture of the stuff inside the duct, but it's not working out too well. The idea of taking an establishing shot is a great one, so I snapped two: one with the vent cover on and one with the vent cover off. Upon closer inspection, it almost looks like whatever it is is seeping through the drywall. Not sure if it's a strange chemical reaction to something or what. I took a second picture with a flash, and I see little black bits. But when I look with my naked eye, in the actual heating vent, there's no black. Not sure what this means as I'm no camera expert! Sorry for the quality of the photos. This is the best I can do http://i.imgur.com/Nn506E3.jpg http://i.imgur.com/Nn506E3.jpg http://i.imgur.com/mBbdakN.jpg