Balancing of Industrial Ventilation Systems

The body of information contained in this paper is directed to those individuals involved in the design and installation of air pollution control systems. When several sources are connected to one ventilation system, a critical part of the overall design is directed to assuring that the system is balanced so that the correct volume is exhausted from each point. The preferable technique for accomplishing this in industrial ventilation systems is the slide gate adjustment method, which can require extensive field adjustment to determine the final slide gate positions. In this study the pressure loss characteristics of slide gate dampers have been measured as a function of damper position, for both round and rectangular ductwork. Generalized graphs are presented that allow for the determination of damper position during the design phase, based on the amount of resistance that must be added to a given branch. Application of this technique indicates it to be both accurate and reliable and significantly reduces the time required to balance a system.