Hey, after reading what you posted I tried to figure out what you would gain and I can't see it working out. First you will always want less splitting and bending and cornering when you are working with ducting and fans. Check out my new log there are some shots of the inside of my box that may help ya. Also Bigtopfin has a grow log about his two TW plants and he goes over some different setups as well. I am basically leaving one end open and then on the other end I am using a duct fan to push hot air out of the box and thru a carbon filter. My goal was to get a somewhat neg air exchange going where the fan exhausting the air out was also pulling the fresh air into the box with the help of a small 4'' duct booster fan. That will work for me only if I get a better cfm rated duct fan the boosters are just not enough. Lets see some pics of what you are working with and on...that would help.