Basic Documentation
Table Of Contents
- About this Application Guide
- Chapter 1–Introduction
- Chapter 2–Physics of Sound
- Chapter 3–HVAC Sound Sources
- Chapter 4–HVAC Sound Attenuation
- Introduction to HVAC Sound Attenuation
- Plenums
- Duct Attenuation
- Duct Takeoffs and Divisions
- Duct Silencers
- End Reflection
- Environment Adjustment Factor
- Space Effect
- Radiated Sound Attenuation
- Chapter 5–HVAC System Sound Analysis
- Chapter 6–Minimizing HVAC Sound
- Appendix
- Glossary
- Index
Table of Contents
About this Application Guide I
Purpose of this Guide I
How this Guide is Organized I
Suggested Reference Materials II
Symbols III
Getting Help III
Where to Send Comments III
Chapter 1–Introduction 1
Scope of This Guide 1
HVAC Sound Transmission 2
Background Sound 2
Laboratory Applicability 2
Computer Program Sound Analysis 2
Chapter 2–Physics of Sound 5
Sound Wave Propagation 5
Sound Wave Parameters 6
Sound Measurement Parameters 8
Sound Power Level 8
Decibels 9
Sound Pressure Level 11
Octave Bands 13
A-Weighted Sound Level 16
NC Curves 17
RC Curves 18
Determining an RC Rating 20
Step 1. Measure Existing Sound Pressure 20
Step 2. Mark Average Sound Pressure 20
Step 3. Plot Curve of Octave Band 21
Example RC Analysis 21
Chapter 3–HVAC Sound Sources 23
Sources of Sound in HAVC Systems 23
Fan Sound Components 24
Fan Aerodynamic Sound 24
Siemens Building Technologies, Inc. i