Why is it important to not make right angle penetrations when building duct branch fittings?
Air, like water, is not real cooperative when asked to make severe turns in its flow. An “L” shaped, 90º (right angle) turn is one of the most severe forms of flow deviations that can be incorporated into a ducting system design. Air tends to bounce around in this location (causing “vortexes” and “turbulence”) which takes a bit of time and increased velocity to “straighten” out. This results in much increased static pressures and friction at this location in addition to increasing inefficiency. It is recommended that branch fittings be made at a 30º angles. Our standard branch fittings are at this angle of deviation.
