$4.)$ If the loop duct on the floor of a building must carry $10,000f\frac{t^3}{m}in$ of chilled air, and it is desired that the maximum air flow velocity does not exceed $1,250$ feet$/$minute:

Size the duct using an Aspect Ratio of $4\mathrm{.}0$

If the story height is ${12}^{\text{'}}-0^{\text{'}\text{'}},$ the ceiling height is $9^{\text{'}}-0",$ the thickness of the concrete floor slab is $6,$ and the ceiling assembly is $4,$ will this ductwork fit abbove the ceiling? With $2"$ insulation?