a/c ductwork and wall penetration

I've read the book and studied the forum. But I still have a couple of questions. Thanks for the great book Rod! The plan is to use a package unit (like a rooftop or mobile home a/c) and leave all of the mechanical noise outside. My room is approximately 24 ft x 24 ft. It has one exterior wall. The ceiling slopes from about 9 ft to 10.5 ft. I can't run the ductwork over the ceiling because there are beams in the way, but I have access to outside the walls from the attic, except for the one exterior wall. Should I run all the ductwork outside the walls and penetrate the wall for each of the supply and return registers or would it be better to penetrate the wall only once and run the ductwork through a furdown, exiting the furdown for each register? Am I making sense? Also, what is the best way to insulate the penetrations? What about the thin sheetmetal boots for the registers? I know that it would be too much trouble (for me and my uses) to insulate the entire duct run with 2 sheets of drywall, but I'm betting someone has a good compromise. :mrgreen: Thanks! Scott

Picture says a 1000 words. try the search engine on HVAC, theres plenty of info in here