Which guru did you get? It really doesn't matter, I'm just curious. I've found with mine, I don't close the fan damper, but close the top vent more than you would believe. This will change a bit as you use yours, but mostly be aware the the grill will over shoot easily, and, as stated, it's very hard to bring back down. Once you get the hang of it, set it and forget it becomes very real. Sent from my iPad using Tapatalk