Louver Dampers :
Louver dampers are best applied to balance or control flow. The
normal leak path of 0.7% of duct area produces a three to five percent
leak rate in average applications.
As a general rule , a damper should be used in the middle third of
the control range for best results. This gives equal percentage in
either direction should the need arise. Your DDI representative
can advise you the way your control requirements can be met.
A variety of options are available. Metallic spring seals,
sealed (dust tight) blade ends, shear seals, and many materials are
available. This custom equipment is designed specifically to fit
Leakage performance of a louver depends on ratio of flowing to
shutoff pressure, design temperature, number of blades, and blade edge
treatment. Since the first two are system related, the last two
are the usual areas of improvement. Reduction of number of blades
reduces leak path to the limit that a single blade has only perimeter
DDI louver dampers are full welded equipment designed for long
service, low maintenance, and easy repair.
Damper Operators will be specified, supplied, mounted, and tested
when requested. A wide variety of operators can be
specified-electric, pneumatic, hydraulic or manual - you choose the one
best suited for your particular application.