barrel bench question

i see most barrel benches just open inside. could a guy use duct work in cob in half the area(split down middle length ways) then have it dump into the other half, that's open, to flow back then out a flue by the barrel? if the flow isnt impaired, it would be a little of both worlds. use the hotter first section in the cob to charge it up, and the last open section for faster heat in the front. i hope im explaining myself ok.

I think it is a great idea Ronald. In another thread there was discussion of exactly this idea, minus the cob inside, and I am still really excited about it. I would say that as long as your CSA of the remaining half barrel is equal or greater than system CSA it will work great. Here's the thread where we were discussing the concept:

http://donkey32.proboards.com/thread/1064/widening-flue-turns-matter

thank you Matt