MANY YEARS AGO, I paid good money out of my own pocket to learn how to design a duct system. I won’t say to whom I paid this money, because I got ripped off. What I “learned” was how to find .1 on a ...

In 1948, research by R.G. Huebscher established flow resistance for different shapes of ductwork at equal velocities, which allowed the creation of the duct-sizing calculator or “Ductulator” for ...