Basic Documentation

About this Application Guide
Round Acoustically Lined Sheet Metal Ducts 57
Duct Elbows 58
Example Rectangular Duct Elbow Attenuation Calculation 60
Duct Takeoffs and Divisions 60
Duct Silencers 62
End Reflection 62
Environment Adjustment Factor 63
Space Effect 63
Radiated Sound Attenuation 64
Chapter 5–HVAC System Sound Analysis 67
Introduction to HVAC System Sound Analysis 67
Example HVAC System Sound Analysis 67
Step 1. Actual Operating Conditions Increase 68
Step 2. Blade Frequency Increment (BFI) 69
Step 3. Efficiency Correction 69
Duct Section A 70
Duct Elbow B 70
Duct Section C 72
Junction D 73
Duct Section E 75
Junction F 76
Duct Section G 76
Duct Takeoff/Junction H 77
Duct Section I 80
Duct Elbow J 80
Reheat Terminal 82
Duct Sections L 82
Perforated Diffuser 83
End Reflection 83
Space Effect 83
Commentary on HVAC System Sound 88
Laboratory Room Sound Analysis 88
Laboratory Room Ambient Sound 89
Fume Hood Sound 89
Terminal Radiated Sound -Example Analysis 90
Radiated Sound 91
Discharge Sound 93
Terminal Radiated Sound -Example Analysis 2 94
Siemens Building Technologies, Inc. iii