Hello
I have added a room to my home and the A/C tech connected a new 7" flex duct to the plenum. Off of that he SAID(??) he connected a 7" wye with 6" reducers. And then off of that he connected a 5" duct dropping into a 64 sq ft. room and a 5" duct dropping into a 77 sq. ft. room This does not add up for me if a 7" carries about 170 CFM and 2, 5" ducts carrying about 70 CFM each. Thats 140 CFM. What happens to the other 30???
Please let me know if this is correct duct design.
Thank You!!!!!!!!