HVAC Systems Duct Design

HVAC Systems Duct Design

SMACNA

Description

The fourth edition of HVAC Systems Duct Design presents the basic methods and procedures required to design HVAC air distribution systems. This manual provides the HVAC system designer detailed information on duct design and U.S. and metric units are provided in all examples, calculations, and tables.

In addition to the basic engineering guidelines for the sizing of HVAC ductwork systems, the manual also provides related information on:

  • materials,
  • methods of construction,
  • economics of duct systems,
  • duct system layout,
  • pressure losses,
  • fan selection,
  • duct leakage,
  • acoustic considerations, and
  • Testing, Adjusting and Balancing (TAB).

Details

Topic
Technical Manuals, Design Guides, HVAC Duct Construction Standards, Technical Standards
Media Type
Book
Publication Year
2006
Page Count
392
Edition
Fourth

Table of Contents

FOREWORD
iii
SMACNA DUCT DESIGN COMMITTEE
iv
NOTICE TO USERS OF THIS PUBLICATION
v
TABLE OF CONTENTS
vii
CHAPTER 1 INTRODUCTION
1.1
1.1 SCOPE
1.1
1.2 HOW TO USE THIS MANUAL
1.1
1.3 PURPOSE
1.1
1.4 HISTORY OF AIR DUCT SYSTEMS
1.1
1.5 GENERAL REQUIREMENTS
1.2
1.6 HVAC SYSTEMS LIBRARY
1.2
1.7 CODES AND ORDINANCES
1.3
1.8 HVAC DUCT SYSTEM TYPES
1.5
1.9 SMOKE CONTROL SYSTEMS
1.6
1.10 INDOOR AIR QUALITY
1.7
1.11 VENTILATION RATES
1.8
FIGURE 1-1 U.S.A. BUILDING CODES AND ORDINANCES
1.4
CHAPTER 2 ECONOMICS OF DUCT SYSTEMS
2.1
2.1 SCOPE
2.1
2.2 RESPONSIBILITIES
2.1
2.3 INITIAL SYSTEM COSTS
2.2
2.4 ANNUAL OWNING COSTS
2.3
2.5 ANNUAL OPERATING COSTS
2.3
2.6 OPERATION COSTS
2.3
2.7 CONTROLLING COSTS
2.5
2.8 DUCT ASPECT RATIOS
2.5
2.9 PRESSURE CLASSIFICATION AND LEAKAGE
2.5
2.10 COST OF FITTINGS
2.7
Table 2-1 Annual Life Cycle Cost Factors
2.2
Table 2-2 Cost of Owning and Operating a Typical Commercial Building
2.3
Table 2-3 Initial Cost Systems
2.4
Table 2-4 Aspect Ratio Example
2.5
Table 2-5 Relative Duct System Costs (Fabrication and installation of same size duct)
2.7
Table 2-6 Estimated Equipment Service Lives
2.8
FIGURE 2-1 RELATIVE COSTS OF DUCT SEGMENTS INSTALLED
2.6
FIGURE 2-2 RELATIVE INSTALLED COST VERSUS ASPECT RATIO
2.6
FIGURE 2-3 RELATIVE OPERATING COST VERSUS ASPECT RATIO
2.7
CHAPTER 3 ROOM AIR DISTRIBUTION
3.1
3.1 SCOPE
3.1
3.2 COMFORT
3.1
3.3 AIR DISTRIBUTION FUNDAMENTALS
3.13
3.4 OUTLET LOCATION
3.15
3.5 OUTLET CRITERIA
3.20
3.6 GRILLE AND REGISTER APPLICATIONS
3.20
3.7 SLOT DIFFUSER APPLICATIONS
3.20
3.8 CEILING DIFFUSER APPLICATIONS
3.21
3.9 OUTLETS IN VARIABLE AIR VOLUME (VAV) SYSTEMS
3.23
3.10 INLET CRITERIA
3.23
3.11 EXHAUST OUTLETS
3.25
3.12 SPECIAL SITUATIONS
3.25
3.13 AIR DISTRIBUTION SUMMARY
3.25
3.14 ROOM TERMINAL DEVICES
3.26
3.15 SUPPLY AIR GRILLE AND REGISTER TYPES
3.28
3.16 SUPPLY AIR CEILING DIFFUSER TYPES
3.28
3.17 VAV AND THERMAL BOXES
3.29
3.18 TERMINAL BOX VARIATIONS
3.30
3.19 BASIC VAV SYSTEM DESIGN
3.31
3.20 VAV COMPONENTS AND CONTROLS
3.32
3.21 VAV SYSTEM ADVANTAGES
3.33
3.22 VAV SYSTEM DESIGN PRECAUTIONS
3.33
3.23 VAV TERMINAL DEVICES
3.35
Table 3-1 Metabolic Rates of Typical Tasks
3.1
Table 3-2 Operative Temperatures for Thermal Acceptability of Sedentary or slightly Active persons ( 1.2 Mets) at 50 percent Relative Humiditya
3.4
Table 3-3 Clo Units for Individual Items of Clothing = 0.82 ( Individual Items)
3.8
Table 3-4 Characteristic Room Lengths for Diffusers
3.10
Table 3-5 Air Diffusion Performance Index (ADPI)
3.12
Table 3-6 Guide for Selection of Supply Outlets
3.17
Table 3-7 Supply Air Outlet Types
3.22
Table 3-8 Supply Air Outlet Performance
3.24
Table 3-9 Recommended Return Air Inlet Face Velocities
3.26
Table 3-10 Return and Exhaust Air Inlet Types
3.26
Table 3-11 Accessory devices
3.27
FIGURE 3-1 CLOTHING INSULATION NECESSARY FOR VARIOUS LEVELS OF COMFORT AT A GIVEN TEMPERATURE DURING LIGHT, MAINLY SEDENTARY ACTIVITIES
3.3
FIGURE 3-2 COMFORT ZONE
3.6
FIGURE 3-3 RANGE OF AVERAGE AIR MOVEMENTS PERMITTED IN THE SUMMER AND EXTENDED SUMMER ZONES
3.7
FIGURE 3-4 OPTIMUM OPERATIVE TEMPERATURES FOR ACTIVE PEOPLE IN LOW AIR MOVEMENT ENVIRONMENTS
3.9
FIGURE 3-5 PERCENTAGE OF OCCUPANTS OBJECTING TO DRAFTS IN AIR-CONDITIONED ROOMS (I-P)
3.11
FIGURE 3-6 PERCENTAGE OF OCCUPANTS OBJECTING TO DRAFTS IN AIR-CONDITIONED ROOMS (SI)
3.11
FIGURE 3-7 SURFACE (COANDA) EFFECT
3.13
FIGURE 3-8 OUTLET VELOCITY AND AIR DIRECTION DIAGRAMS FOR STACK HEADS WITH EXPANDING OUTLETS
3.16
FIGURE 3-9 AIR MOTION CHARACTERISTICS OF GROUP A OUTLETS
3.17
FIGURE 3-10 AIR MOTION CHARACTERISTICS OF GROUP B OUTLETS
3.18
FIGURE 3-11 AIR MOTION CHARACTERISTICS OF GROUP C OUTLETS
3.19
FIGURE 3-12 AIR MOTION CHARACTERISTICS OF GROUP D OUTLETS
3.19
FIGURE 3-13 AIR MOTION CHARACTERISTICS OF GROUP E OUTLETS
3.20
CHAPTER 4 GENERAL APPROACH TO DUCT DESIGN
4.1
4.1 SCOPE
4.1
4.2 DESIGN METHODS - OVERVIEW
4.3
4.3 SELDOM USED METHODS
4.4
4.4 DUCT HEAT GAIN OR LOSS
4.5
4.5 SOUND AND VIBRATION
4.5
4.6 PRESSURE CLASSIFICATION
4.5
4.7 DUCT LEAKAGE
4.6
4.8 FAN SIZING
4.6
4.9 TESTING, ADJUSTING AND BALANCING (TAB)
4.6
4.10 FINAL DESIGN DOCUMENTS
4.6
Table 4-1 HVAC Duct Pressure Velocity Classification
4.5
FIGURE 4-1 DUCT PRESSURE CLASS DESIGNATION (I-P)
4.7
FIGURE 4-1M DUCT PRESSURE CLASS DESIGNATION (SI)
4.8
FIGURE 4-2 SYMBOLS FOR VENTILATION AND AIR CONDITIONING (I-P)
4.9
FIGURE 4-2M SYMBOLS FOR VENTILATION AND AIR CONDITIONING (SI)
4.10
CHAPTER 5 DUCT DESIGN FUNDAMENTALS
5.1
5.1 SCOPE
5.1
5.2 FLUID PROPERTIES
5.1
5.3 FLUID STATICS
5.2
5.4 FLUID DYNAMICS
5.3
5.5 FLUID FLOW PATTERNS
5.6
5.6 DUCT SYSTEM PRESSURES
5.9
5.7 FRICTION LOSSES
5.10
5.8 DYNAMIC LOSSES
5.12
5.9 BASIC DUCT SIZING
5.14
5.10 DUCT CONFIGURATIONS
5.16
5.11 DUCT FITTINGS
5.18
5.12 SYSTEM PRESSURE CHANGES
5.22
5.13 STRAIGHT DUCT LOSSES
5.25
5.14 DYNAMIC LOSSES
5.25
5.15 SPLITTER VANES
5.27
5.16 TURNING VANES
5.27
5.17 PRESSURE LOSSES IN DIVIDED-FLOW FITTINGS
5.30
5.18 LOSSES DUE TO AREA CHANGES
5.31
5.19 OTHER LOSS COEFFICIENTS
5.31
5.20 OBSTRUCTION AVOIDANCE
5.32
5.21 DUCT AIR LEAKAGE
5.34
5.22 DUCT HEAT GAIN/LOSS
5.38
5.23 SMACNA DUCT RESEARCH
5.40
5.24 FAN PRESSURES
5.41
5.25 FAN DEFINITIONS
5.42
5.26 FAN LAWS
5.44
5.27 FAN TESTING
5.46
5.28 FAN CLASSIFICATIONS
5.46
5.29 FAN TYPES
5.46
5.30 FAN CURVES
5.49
5.31 DUCT SYSTEM AIRFLOW
5.52
5.32 SYSTEM CURVES
5.52
5.33 AIR DENSITY EFFECTS
5.56
5.34 ESTIMATING SYSTEM RESISTANCE
5.58
5.35 SAFETY FACTORS
5.59
5.36 THE FAN OUTLET
5.59
5.37 THE FAN INLET
5.63
5.38 ASHRAE METHODS
5.64
5.39 FUNDAMENTALS HANDBOOK
5.66
5.40 DEFICIENT FAN PERFORMANCE
5.67
5.41 SYSTEM EFFECT FACTORS
5.67
5.42 BUILDING PRESSURES
5.70
5.43 BUILDING AIRFLOW CONTROL
5.73
Table 5-1 Unsealed Longitudinal Seam Leakage For Metal Ducts
5.33
Table 5-2 Applicable Leakage Classesa
5.36
Table 5-3 Leakage As A Percentage of System Airflow
5.36
Table 5-4 K Values for Outlet Ducts
5.65
Table 5-5 K Values for Single Width, Single Inlet Fans (SWSI)
5.66
FIGURE 5-1 CAPILLARY ACTION
5.2
FIGURE 5-2 VELOCITY PROFILE
5.3
FIGURE 5-3 RELATION BETWEEN FRICTION FACTOR AND REYNOLDS NUMBER
5.4
FIGURE 5-4 VELOCITY PROFILES OF FLOW IN DUCTS
5.7
FIGURE 5-5 SEPARATION IN FLOW IN A DIFFUSER
5.7
FIGURE 5-6 CHANGING VELOCITY PROFILES AT A MITERED ELBOW
5.8
FIGURE 5-7 EFFECT OF DUCT LENGTH ON DAMPER ACTION
5.8
FIGURE 5-8 PART DUCT FRICTION LOSS CHART (I-P)
5.15
FIGURE 5-9 PART DUCT FRICTION LOSS CHART (SI)
5.16
FIGURE 5-10 PRESSURE CHANGES DURING FLOW-IN DUCTS
5.24
FIGURE 5-11 RETURN AIR DUCT EXAMPLE
5.24
FIGURE 5-12 TO CALCULATE SPLITTER VANE SPACING FOR A SMOOTH RADIUS RECTANGULAR ELBOW
5.27
FIGURE 5-13 TURNING VANES RESEARCH
5.28
FIGURE 5-14 TURBULENCE CAUSED BY IMPROPER MOUNTING AND USE OF TURNING VANES
5.29
FIGURE 5-15 PROPER INSTALLATION OF TURNING VANES
5.30
FIGURE 5-16 AMCA DAMPER TESTS
5.32
FIGURE 5-17 DUCT OBSTRUCTIONS
5.32
FIGURE 5-18 EXAMPLE 5-5 FAN/SYSTEM CURVE
5.34
FIGURE 5-19 DUCT LEAKAGE CLASSIFICATIONS
5.35
FIGURE 5-20 RECTANGULAR ELBOW 90 DEGREE THROAT, 90 DEGREE HEEL
5.40
FIGURE 5-21 DIFFERENT CONFIGURATION ELBOW RESEARCH
5.41
FIGURE 5-22 END TAP RESEARCH
5.42
FIGURE 5-23 FAN TOTAL PRESSURE (TP)
5.43
FIGURE 5-24 FAN STATIC PRESSURE (SP)
5.43
FIGURE 5-25 FAN VELOCITY PRESSURE (VP)
5.43
FIGURE 5-26 TIP SPEED
5.44
FIGURE 5-27 CENTRIFUGAL FAN COMPONENTS
5.45
FIGURE 5-28 AXIAL FAN COMPONENTS
5.46
FIGURE 5-29 METHOD OF OBTAINING FAN PERFORMANCE CURVES
5.47
FIGURE 5-30 CHARACTERISTIC CURVES FOR FC FANS
5.47
FIGURE 5-31 CHARACTERISTIC CURVES FOR BI FANS
5.48
FIGURE 5-32 CHARACTERISTIC CURVES FOR AIRFOIL FANS
5.48
FIGURE 5-33 TUBULAR CENTRIFUGAL FAN
5.48
FIGURE 5-34 CHARACTERISTIC CURVES FOR TUBULAR CENTRIFUGAL FANS
5.49
FIGURE 5-35 CHARACTERISTIC CURVES FOR PROPELLER FANS
5.49
FIGURE 5-36 CHARACTERISTIC CURVES FOR VANEAXIAL FANS
5.49
FIGURE 5-37 APPLICATION OF THE FAN LAWS
5.50
FIGURE 5-38 CENTRIFUGAL FAN PERFORMANCE TABLE (I-P)
5.51
FIGURE 5-39 CENTRIFUGAL FAN PERFORMANCE TABLE (METRIC UNITS)
5.51
FIGURE 5-40 SYSTEM RESISTANCE CURVE
5.52
FIGURE 5-41 FAN CURVE PLOTS
5.53
FIGURE 5-42 NORMALIZED DUCT SYSTEM CURVES
5.54
FIGURE 5-43 OPERATING POINT
5.54
FIGURE 5-44 VARIATIONS FROM DESIGN – AIR SHORTAGE
5.54
FIGURE 5-45 EFFECT OF 10 PERCENT INCREASE IN FAN SPEED
5.55
FIGURE 5-46 INTERACTIONS OF SYSTEM CURVES AND FAN CURVE
5.56
FIGURE 5-47 EFFECT OF DENSITY CHANGE (CONSTANT VOLUME)
5.56
FIGURE 5-48 EFFECT OF DENSITY CHANGE (CONSTANT STATIC PRESSURE)
5.57
FIGURE 5-49 EFFECT OF DENSITY CHANGE (CONSTANT MASS FLOW)
5.58
FIGURE 5-50 DUCT SYSTEM CURVE NOT AT DESIGN POINT
5.59
FIGURE 5-51 AMCA FAN TEST – PITOT TUBE
5.60
FIGURE 5-52 ESTABLISHMENT OF A UNIFORM VELOCITY PROFILE
5.61
FIGURE 5-53 EFFECTS OF SYSTEM EFFECT
5.62
FIGURE 5-54 SYSTEM EFFECT CURVES FOR INLET DUCT ELBOWS – AXIAL FANS
5.63
FIGURE 5-55 SAMPLE ASHRAE FAN SYSTEM EFFECT “LOSS COEFFICIENTS”
5.68
FIGURE 5-56 CHANGES FROM SYSTEM EFFECT
5.69
FIGURE 5-57 SENSITIVITY OF SYSTEM VOLUME TO LOCATIONS OF BUILDING OPENINGS, INTAKES, AND EXHAUSTS
5.70
FIGURE 5-58 BUILDING SURFACE FLOW PATTERNS
5.71
FIGURE 5-59 PRESSURE DIFFERENCE DUE TO STACK EFFECT
5.72
FIGURE 5-60 AIR MOVEMENTS DUE TO NORMAL AND REVERSE STACK EFFECT
5.73
CHAPTER 6 FAN-DUCT CONNECTION PRESSURE LOSSES
6.1
6.1 SCOPE
6.1
6.2 FAN OUTLET CONDITIONS
6.1
6.3 FAN INLET CONDITIONS
6.7
6.4 EFFECTS OF FACTORY SUPPLIED ACCESSORIES
6.13
6.5 CALCULATING SYSTEM EFFECT
6.16
Table 6-1 System Effect Curves for Outlet Ducts
6.4
Table 6-2 System Effect Factor Curves for Outlet Elbows
6.6
Table 6-3 System Effect Curves for Inlet Obstructions
6.16
Table 6-4
6.17
FIGURE 6-1 SYSTEM EFFECT CURVES
6.2
FIGURE 6-2 CONTROLLED DIFFUSION AND ESTABLISHMENT OF A UNIFORM VELOCITY PROFILE IN A STRAIGHT LENGTH OF OUTLET DUCT
6.3
FIGURE 6-3 OUTLET DUCT ELBOWS
6.5
FIGURE 6-4 PARALLEL VERSUS OPPOSED DAMPERS
6.7
FIGURE 6-5 TYPICAL HVAC UNIT CONNECTIONS
6.8
FIGURE 6-6 TYPICAL INLET CONNECTIONS FOR CENTRIFUGAL AND AXIAL FANS
6.8
FIGURE 6-7 NON-UNIFORM FLOW INTO A FAN INLET INDUCED BY A 90 DEGREE ROUND SECTION ELBOW - NO TURNING VANES
6.9
FIGURE 6-8 NON-UNIFORM FLOW INDUCED INTO FAN INLET BY A RECTANGULAR INLET DUCT
6.9
FIGURE 6-9 SYSTEM EFFECTS FOR VARIOUS MITERED ELBOWS WITHOUT VANES
6.10
FIGURE 6-10 SYSTEM EFFECTS FOR SQUARE DUCT ELBOWS
6.11
FIGURE 6-11 EXAMPLE OF A FORCED INLET VORTEX (SPIN-SWIRL)
6.12
FIGURE 6-12 INLET DUCT CONNECTIONS CAUSING INLET SPIN
6.12
FIGURE 6-13 CORRECTIONS FOR INLET SPIN
6.13
FIGURE 6-14 AMCA STANDARD 210 FLOW STRAIGHTENER
6.13
FIGURE 6-15 SYSTEM EFFECT CURVES FOR FANS LOCATED IN PLENUMS AND CABINET ENCLOSURES AND FOR VARIOUS WALL TO INLET DIMENSIONS
6.14
FIGURE 6-16 ENCLOSURE INLET NOT SYMMETRICAL WITH FAN INLET, PREROTATIONAL VORTEX INDUCED
6.14
FIGURE 6-17 FLOW CONDITION OF FIGURE 6-16 IMPROVED WITH A SPLITTER SHEET
6.14
FIGURE 6-18 CENTRIFUGAL FAN INLET BOX
6.15
FIGURE 6-19 FREE INLET AREA PLANE - FAN WITH INLET COLLAR
6.16
FIGURE 6-20 FREE INLET AREA PLANE - FAN WITHOUT INLET COLLAR
6.16
FIGURE 6-21 TYPICAL NORMALIZED INLET VALVE CONTROL PRESSURE - VOLUME CURVE
6.17
FIGURE 6-22 COMMON TERMINOLOGY FOR CENTRIFUGAL FAN APPURTRENANCES
6.18
CHAPTER 7 DUCT SIZING PROCEDURES
7.1
7.1 SCOPE
7.1
7.2 DESIGN OBJECTIVES
7.1
7.3 DUCT SYSTEM SIZING PROCEDURES
7.1
7.4 FITTING PRESSURE LOSS TABLES
7.2
7.5 SUPPLY AIR DUCT SYSTEM-SIZING EXAMPLE 1 (I-P)
7.4
7.6 RETURN AIR (EXHAUST AIR) DUCT SYSTEM-SIZING EXAMPLE 2
7.18
7.7 SUPPLY AIR DUCT SYSTEM SIZING EXAMPLE 3 (I-P)
7.21
7.8 EXTENDED PLENUM DUCT SIZING
7.26
7.9 DESIGN FUNDAMENTALS (SI)
7.32
7.10 SUPPLY AIR DUCT SYSTEM – SIZING EXAMPLE. 1 (SI)
7.32
7.11 RETURN AIR (EXHAUST AIR) DUCT SYSTEM-SIZING EXAMPLE 2 (SI)
7.40
7.12 SUPPLY AIR DUCT SYSTEM SIZING EXAMPLE 3 (SI)
7.47
7.13 EXTENDED PLENUM DUCT SIZING
7.52
Table 7-1 Duct Sizing, Supply Air System - Example 1
7.6
Table 7-1 (a) Duct Sizing, Supply Air System - Example 1 (Continued)
7.7
Table 7-2 Duct Sizing, Exhaust Air System – Example 2 (I–P)
7.15
Table 7-3 Duct Sizing, Exhaust Air System – Example 3 (I–P)
7.16
Table 7-3(a) Duct Sizing, Exhaust Air System – Example 3 (I–P) (Continued)
7.17
Table 7-4 Semi-Extended Plenum Comparison
7.28
Table 7-5 Semi-Extended Plenum Installation Cost Comparison
7.28
Table 7-6 Duct Sizing, Supply Air System – Example 1
7.30
Table 7–6(a) Duct Sizing, Supply Air System – Example 1 (Continued)
7.31
Table 7-7 Duct Sizing, Exhaust Air System – Example 2 (SI)
7.44
Table 7-8 Duct Sizing, Supply Air System – Example 3
7.45
Table 7–8(a) Duct Sizing, Supply Air System – Example 3 (Continued)
7.46
Table 7-9 Semi-Extended Plenum Comparison
7.53
Table 7-10 Semi-Extended Plenum Installation Cost Comparison
7.53
FIGURE 7-1 DUCT SYSTEMS FOR DUCT SIZING EXAMPLES 1 AND 2
7.5
FIGURE 7-2 SUPPLY AIR DUCT SYSTEM FOR SIZING EXAMPLE 3
7.23
FIGURE 7-3 SYSTEM “A” – SIZED BY EQUAL FRICTION METHOD
7.27
FIGURE 7-4 SYSTEM “B” – MODIFIED BY SEMI-EXTENDED PLENUM CONCEPT
7.28
FIGURE 7-5 DUCT SIZING WORK SHEET (I-P)
7.29
FIGURE 7-6M DUCT SYSTEMS FOR DUCT SIZING EXAMPLES 1 AND 2 (SI)
7.33
FIGURE 7-7M SUPPLY AIR DUCT SYSTEM FOR SIZING EXAMPLE 3
7.47
FIGURE 7-8M SYSTEMS “A” SIZED BY EQUAL FRICTION METHOD
7.53
FIGURE 7-9M “B” MODIFIED BY SEMI-EXTENDED PLENUM CONCEPT
7.54
FIGURE 7-10 DUCT SIZING WORK SHEET (I-P)
7.55
FIGURE 7-10M DUCT SIZING WORK SHEET (SI)
7.56
CHAPTER 8 PRESSURE LOSS OF SYSTEMS COMPONENTS
8.1
8.1 SCOPE
8.1
8.2 USE OF TABLES AND CHARTS
8.1
8.3 DAMPER CHARTS
8.8
8.4 DUCT SYSTEM APPARATUS CHARTS
8.9
8.5 ROOM AIR TERMINAL DEVICES
8.15
8.6 LOUVER DESIGN DATA
8.17
Table 8-1 Filter Pressure Loss Data
8.1
Table 8-2 Louver Free Area Chart 2 in. Blades at 45 Degree Angle
8.4
Table 8-3 Louver Free Area Chart 4 in. Blades at 45 Degree Angle
8.5
Table 8-4 Louver Free Area Chart 6 in. Blades at 45 Degree Angle
8.6
Table 8-5 Air Outlets & Diffusers – Total Pressure Loss Average
8.15
Table 8-6 Supply Registers – Total Pressure Loss Average
8.15
Table 8-7 Return Registers – Total Pressure Loss Average
8.15
Table 8-8 Typical Design Velocities
8.16
FIGURE 8-1 SYSTEM PRESSURE LOSS CHECK LIST
8.3
FIGURE 8-2 VOLUME DAMPERS (*BASED UPON AMCA CERTIFIED VOLUME DAMPERS)
8.8
FIGURE 8-3 BACKDRAFT OR RELIEF DAMPERS
8.8
FIGURE 8-4 2-HOUR FIRE & SMOKE DAMPERS (BASED ON AMCA CERTIFIED FIRE DAMPERS)
8.8
FIGURE 8-5 HEATING COILS WITH 1 ROW
8.9
FIGURE 8-6 HEATING COILS WITH 2 ROWS
8.9
FIGURE 8-7 HEATING COILS WITH 3 ROWS
8.9
FIGURE 8-8 HEATING COILS WITH 4 ROWS
8.9
FIGURE 8-9 COOLING COILS (WET) 4 ROW
8.10
FIGURE 8-10 COOLING COILS (WET) 6 ROW
8.10
FIGURE 8-11 COOLING COILS (WET) 8 ROW
8.10
FIGURE 8-12 AIR MONITOR DEVICE
8.10
FIGURE 8-13 LOUVERS WITH 45 BLADE ANGLE (*BASED ON AMCA CERTIFIED LOUVERS)
8.11
FIGURE 8-14 3 RECTANGULAR SOUND TRAPS – 3 FOOT (1M)
8.11
FIGURE 8-15 RECTANGULAR SOUND TRAPS – 5 FOOT (1.5M)
8.11
FIGURE 8-16 RECTANGULAR SOUND TRAPS – 7 FOOT (2M)
8.11
FIGURE 8-17 RECTANGULAR SOUND TRAPS – 10 FOOT (3M)
8.12
FIGURE 8-18 ROUND SOUND TRAPS
8.12
FIGURE 8-19 ELIMINATORS THREE BEND
8.12
FIGURE 8-20 AIR WASHER
8.12
FIGURE 8-21 SCREENS
8.13
FIGURE 8-22 AIR-TO-AIR PLATE EXCHANGERS (MODULAR)
8.13
FIGURE 8-23 AIR-TO-AIR SINGLE TUBE EXCHANGERS
8.13
FIGURE 8-24 ROTARY WHEEL EXCHANGER
8.13
FIGURE 8-25 MULTIPLE TOWER ENERGY EXCHANGERS
8.14
FIGURE 8-26 DRY AIR EVAPORATIVE COOLER
8.14
FIGURE 8-27 RECOMMENDED CRITERIA FOR LOUVER SIZING
8.17
CHAPTER 9 PROVISIONS FOR TESTING, ADJUSTING, AND BALANCING
9.1
9.1 SCOPE
9.1
9.2 TAB DESIGN CONSIDERATIONS
9.1
9.3 AIR MEASUREMENT DEVICES
9.5
9.4 BALANCING WITH ORIFICES
9.5
9.5 PROVISIONS FOR TAB IN SYSTEM DESIGN
9.5
9.6 LABORATORY TESTING
9.6
9.7 FIELD TESTING AND BALANCING
9.7
9.8 TEST INSTRUMENTATION
9.10
Table 9-1 Airflow Measuring Instruments
9.11
FIGURE 9-1 DESIGN CONSIDERATIONS FOR DIFFUSER LAYOUTS AND BALANCING DAMPER LOCATIONS
9.2
FIGURE 9-2 DUCT DESIGN CONSIDERATIONS FOR SUGGESTED BALANCING DAMPER LOCATIONS
9.3
FIGURE 9-3 DESIGN CONSIDERATIONS TO MINIMIZE AIRFLOW TURBULENCE AND STRATIFICATION FROM TERMINAL BOXES
9.4
FIGURE 9-4 FAN RATING TEST
9.6
FIGURE 9-5 TYPICAL VELOCITY PROFILES ENCOUNTERED IN VELOCITY PRESSURE MEASUREMENT PLANES
9.9
CHAPTER 10 DESIGNING FOR SOUND AND VIBRATION
10.1
10.1 SCOPE
10.1
10.2 BUILDING NOISE
10.1
10.3 HVAC NOISE
10.2
10.4 COMMON SOUND SOURCES
10.6
10.5 SOUND DATA STANDARDS
10.7
10.6 DUCT NOISE
10.7
10.7 DUCT SILENCERS
10.8
10.8 ACOUSTIC LAGGING
10.10
10.9 DUCT SOUND BREAKOUT
10.10
Table 10-1 Sound Sources, Transmission Paths, and Recommended Noise Reduction Methods
10.5
FIGURE 10-1 SOURCE, PATH, AND RECEIVER
10.1
FIGURE 10-2 MECHANICAL EQUIPMENT ROOM ADJACENT TO OFFICE AREA
10.2
FIGURE 10-3 ILLUSTRATION OF WELL- BALANCED HVAC SOUND SPECTRUM FOR OCCUPIED SPACES
10.3
FIGURE 10-4 FREQUENCY RANGES OF THE MOST LIKELY SOURCES OF ACOUSTICAL COMPLAINTS
10.4
FIGURE 10-5 FREQUENCY AT WHICH DIFFERENT TYPES OF MECHANICAL EQUIPMENT GENERALLY CONTROL SOUND SPECTRA
10.4
FIGURE 10-6 DISSIPATIVE PASSIVE DUCT SILENCERS
10.9
FIGURE 10-7 ACTIVE DUCT SILENCER
10.9
FIGURE 10-8 EXTERNAL DUCT LAGGING ON RECTANGULAR DUCTS
10.10
FIGURE 10-9 BREAKOUT AND BREAK-IN OF SOUND IN DUCTS
10.11
CHAPTER 11 DUCT SYSTEM CONSTRUCTION
11.1
11.1 SCOPE
11.1
11.2 DUCT SYSTEM SPECIFICATION CHECK LIST
11.1
11.3 DUCT CONSTRUCTION MATERIALS
11.1
11.4 ASTM STANDARDS
11.5
Table 11-1 Sheet Metal Properties
11.4
CHAPTER 12 SPECIAL DUCT SYSTEMS
12.1
12.1 SCOPE
12.1
12.2 KITCHEN AND MOISTURE - LADEN SYSTEMS
12.1
12.3 SYSTEMS HANDLING SPECIAL GASES
12.1
12.4 INDUSTRIAL DUCT
12.1
APPENDIX A DUCT DESIGN TABLES AND CHARTS
A.1
FITTING LOSS COEFFICIENT TABLES
A.15
HVAC EQUATIONS (I-P)
A.51
HVAC EQUATIONS (SI)
A.56
SI UNITS AND EQUIVALENTS
A.59
Table A-1 Duct Material Roughness Factors
A.4
Table A-2 Circulation Equivalents of Rectangular Ducts for Equal Friction and Capacity Dimensions (I-P)
A.6
Table A-2 Circulation Equivalents of Rectangular Ducts for Equal Friction and Capacity Dimensions (I-P) (continued)
A.7
Table A-2M Circular Equivalents of Rectangular Ducts for Equal Friction and Capacity Dimensions (SI)
A.8
Table A-3 Spiral Flat-Oval Duct (Nominal Sizes)
A.10
Table A-3M Spiral Flat-Oval Duct (Nominal Sizes)
A.11
Table A-4 Velocities/Velocity Pressures
A.12
Table A-4M Velocities/Velocity Pressures
A.13
Table A-5 Angular Conversion
A.13
Table A-6 Loss Coefficients for Straight-Through Flow
A.14
Table A-7 Loss Coefficients, Elbows
A.15
Table A-7 Loss Coefficients, Elbows (continued)
A.16
Table A-7 Loss Coefficients, Elbows (continued)
A.17
Table A-7 Loss Coefficients, Elbows (continued)
A.18
Table A-7 Loss Coefficients, Elbows (continued)
A.19
Table A-8 Loss Coefficients, Transitions (Diverging Flow)
A.20
Table A-8 Loss Coefficients, Transitions (Diverging Flow) (continued)
A.21
Table A-8 Loss Coefficients, Transitions (Diverging Flow) (continued)
A.22
Table A-9 Loss Coefficients, Transitions (Converging Flow)
A.23
Table A-9 Loss Coefficients, Transitions (Converging Flow) (continued)
A.24
Table A-10 Loss Coefficients, Converging Junctions (Tees, Wyes)
A.24
Table A-10 Loss Coefficients, Converging Junctions (Tees, Wyes) (continued)
A.25
Table A-10 Loss Coefficients, Converging Junctions (Tees, Wyes) (continued)
A.26
Table A-10 Loss Coefficients, Converging Junctions (Tees, Wyes) (continued)
A.27
Table A-10 Loss Coefficients, Converging Junctions (Tees, Wyes) (continued)
A.28
Table A-11 Loss Coefficients, Diverging Junctions (Tees, Wyes)
A.29
Table A-11 Loss Coefficients, Diverging Junctions (Tees, Wyes) (Continued)
A.30
Table A-11 Loss Coefficients, Diverging Junctions (Tees, Wyes) (Continued)
A.31
Table A-11 Loss Coefficients, Diverging Junctions (Tees, Wyes) (Continued)
A.32
Table A-11 Loss Coefficients, Diverging Junctions (Tees, Wyes) (Continued)
A.33
Table A-11 Loss Coefficients, Diverging Junctions (Tees, Wyes) (Continued)
A.34
Table A-11 Loss Coefficients, Diverging Junctions (Tees, Wyes) (Continued)
A.35
Table A-11 Loss Coefficients, Diverging Junctions (Tees, Wyes) (Continued)
A.36
Table A-11 Loss Coefficients, Diverging Junctions (Continued)
A.37
Table A-12 Loss Coefficients, Entries
A.37
Table A-12 Loss Coefficients, Entries (Continued)
A.38
Table A-12 Loss Coefficients, Entries (Continued)
A.39
Table A-12 Loss Coefficients, Entries (Continued)
A.40
Table A-13 Loss Coefficients, Exits
A.40
Table A-13 Loss Coefficients, Exits (Continued)
A.41
Table A-13 Loss Coefficients, Exits (Continued)
A.42
Table A-13 Loss Coefficients, Exits (Continued)
A.43
Table A-14 Loss Coefficients, Screens and Plates
A.44
Table A-15 Loss Coefficients, Obstructions (Constant Velocities)
A.45
Table A-15 Loss Coefficients, Obstructions (Continued)
A.46
Table A-15 Loss Coefficients, Obstructions (Continued)
A.47
Table A-15 Loss Coefficients, Obstructions (Continued)
A.48
Table A-16 Converting Pressure In Inches of Mercury to Feet of Water at Various Water Temperatures
A.53
Table A-17 Air Density Correction Factors
A.54
Table A-17M Air Density Correction Factors
A.55
Table A-18 SI Units (Basic and Derived)
A.59
Table A-19 SI Equivalents
A.60
Table A-20 Recommended NC-RC Levels For Different Indoor Activity Areas
A.61
Table A-21 Listening Conditions And Telephone Use As A Function Of NC-RC Levels
A.62
Table A-22 Sound Sources, Transmission Paths, And Recommended Noise Reduction Methods
A.62
Table A-23 Specific Sound Power Levels, Kw, For Fan Total Sound Power
A.63
Table A-24 Blade Frequency Increments (BFI)
A.63
Table A-25 Correction Factor, C, For Off-Peak Operation
A.63
Table A-26 TLout vs. Frequency For Various Rectangular Ducts
A.64
Table A-27 TLin vs. Frequency For Various Rectangular Ducts
A.64
Table A-28 Experimentally Measured TLout vs. Frequency For Round Ducts
A.64
Table A-29 Calculated TLout vs. Frequency For Round Ducts
A.65
Table A-30 Experimentally Determined TLin vs. Frequency For Round Ducts
A.65
Table A-31 Calculated TLin vs. Frequency For Round Ducts
A.65
Table A-32 TLout vs. Frequency For Various Flat-Oval Ducts
A.66
Table A-33 TLin vs. Frequency For Various Flat-Oval Ducts
A.66
Table A-34 Absorption Coefficients For Selected Plenum Materials
A.66
Table A-35 Sound Attenuation In Unlined Rectangular Sheet Metal Ducts
A.66
Table A-36 Insertion Loss For Rectangular Ducts With 1 in. Of Fiberglass Lining
A.67
Table A-37 Insertion Loss For Rectangular Ducts With 2 in. Of Fiberglass Lining
A.68
Table A-38 Sound Attenuation In Straight Round Ducts
A.69
Table A-39 Insertion Loss For Acoustically Lined Round Ducts - 1 in. Lining
A.69
Table A-40 Insertion Loss For Acoustically Lined Round Ducts—2 in. Lining
A.70
Table A-41 Insertion Loss For Acoustically Lined Round Ducts—3 in. Lining
A.71
Table A-42 Insertion Loss Of Unlined And Lined Square Elbows Without Turning Vanes
A.71
Table A-43 Insertion Loss Of Round Elbows
A.72
Table A-44 Insertion Loss Of Unlined And Lined Square Elbows With Turning Vanes
A.72
Table A-45 7 ft, Rectangular, Standard Pressure Drop Duct Silencers
A.72
Table A-46 7 ft, Rectangular, Low Pressure Drop Duct Silencers
A.73
Table A-47 Round, High Pressure Drop Duct Silencers
A.73
Table A-48 Round, Low Pressure Drop Duct Silencers
A.74
Table A-49 Coefficients For Determining Static Pressure Drop Across Duct Silencers
A.74
Table A-50 Coefficient For System Component Effect On Duct Silencers
A.74
Table A-51 Transmission Loss Values For Ceiling Materials
A.75
Table A-52 Correction Coefficient “ ” For Different Types Of Ceilings
A.75
Table A-53 Average Sound Absorption Coefficients, , For Typical Receiving Rooms
A.75
Table A-54 Air Absorption Coefficients
A.76
Table A-55 Decibel Equivalents Of Numbers (N)
A.76
Table A-56 Five Place Logarithms
A.77
Table A-57 Natural Trigonometric Functions
A.78
FIGURE A-1 DUCT FRICTION LOSS CHART
A.2
FIGURE A-1M DUCT FRICTION LOSS CHART
A.3
FIGURE A-2 DUCT FRICTION LOSS CORRECTION FACTORS
A.5
FIGURE A-3 CORRECTION FACTOR FOR UNEXTENDED FLEXIBLE DUCT
A.12
FIGURE A-4 AIR DENSITY FRICTION CHART CORRECTION FACTORS
A.14
FIGURE A-5 DUCT HEAT TRANSFER COEFFICIENTS
A.49
FIGURE A-5M DUCT HEAT TRANSFER COEFFICIENTS
A.50
INDEX
I.1