Duct trunk sizing
I have two heat heat pumps in my house, one upstairs and one downstairs. Both are two ton units.. Upstairs is 995 sq. ft. And downstairs is 880. I am going to replace the ductboard with metal trunk. The duct calculator slide rule calls for an 8x18 trunk downstairs, and an 8x20 upstairs. Does this sound right? There are 11 takeoffs downstairs and 12 upstairs.