Spliting duct work a bad idea?
I am trying to get some extra head room in my basement. Currently I have 8''x10'' duct running through the middle of my basement. I would like to split it into two 3.25''x10'' ducts runing side by side and then feed even number of registers from each section. Is it ok to do it? the cross sectional area would almost be the same so the amount of air flow should be similar to the original but I would gain more than 4'' in height of the basement.