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 ...
GET IT RIGHT: Duct fitting construction has a large influence on its equivalent length and which air duct calculator setting you choose. The fitting on the left has a much higher equivalent length due ...
A small-duct high-velocity system was used in this Johns Island, SC house. The ducts vents can hardly be seen. The house was designed by Architect Sam Rashkin. Energy Star estimates that 20% to 30% of ...