I add from both from the top and the side door, so either or will work. After I add the split, I open the side door open about half way or all the way depending on how high the heat gets. I've even been known to prop the top door open if I add too much wood and the side door isn't doing the trick (I haven't had to do this much lately once I figured out much wood to add). I'm doing a couple racks of spares on Saturday (almost 3 weeks w/o using it is killing me!) so I'll take a few pics and post to show my process. I did notice though that the smoker was running a little hotter w/ hickory and pecan vs. oak, so don't forget the time of day, weather and what kind of wood you're using will all have an affect on temps. The nut on my intake dampener is a little loose, but not to the point where it restricts me from adjusting the vent properly. It's just loose enough to where it gets hot and the metal expands, it's still functional. On my brisket smoke, it expanded just enough to where it felt like the vent on my Webber Kettle.