I'm in the middle of installing a Trane 3 ton heat pump sytem. There are 15 6 inch supplies in the crawl. I was told to run 2 12 inch flex 25 feet to #2 distribution boxes and run 6 of the 6 inch supplies off of each of the distibution boxes and run the remaining 3 straight off the supply plenum. I'm curious if both the 12 inch flex can carry those 6 runs coming off the distribution boxes. I have already suggested we run 14 to the distribution boxes but I was told 12 inch flex would be fine. I want to know what you would do in this situation??????