The SMACNA HVAC System Duct Design Manual provides effects for inlets and outlets of fans. It also gives tips on noise control in ducts. It features in depth coverage use of extractors, splinters, and dampers.
The SMACNA HVAC System Duct Design Manual offers new loss coefficients for elbows with 45-degree throats on square and radius heels and radius throats with square heels.
Losses compare favorably with elbows with double wall turning vanes in several cases. Structured to offer the designer options in energy-efficient design methods, materials, and construction. Includes soft metrics.
If you're designing duct work for energy efficiency, you need to order this book!