Handbook of air conditioning and refrigeration / Shan K

CHAPTER 20
AIR SYSTEMS: BASICS AND
CONSTANT-VOLUME SYSTEMS
20.1 AIR SYSTEM BASICS 20.2
Air Systems 20.2
Air Distribution Systems 20.3
Ventilation Systems 20.3
Mechanical Ventilation Systems 20.3
Regenerative Systems 20.3
Smoke Control Systems 20.4
Terminals 20.4
Primary, Secondary, and
Transfer Air 20.4
20.2 BUILDING LEAKAGE AREA AND
BUILDING TIGHTNESS 20.5
Effective Leakage Area 20.5
Building Air Leakage 20.5
Air Change Per Hour at 50 Pa
(ACH50) 20.6
20.3 SPACE PRESSURIZATION 20.7
Space Pressure Characteristics 20.7
Stack Effect 20.7
Stack Effect for High-Rise Buildings 20.9
Wind Effect 20.10
Air Systems and Mechanical Ventilation
Systems 20.11
Airflow Balance and Space Pressurization
by Differential Flow 20.11
20.4 INFILTRATION AND
EXFILTRATION 20.14
Volume Flow Rate of Infiltration 20.14
20.5 FAN-DUCT SYSTEMS 20.14
System Operating Point 20.15
Buckingham � Method and
Fan Laws 20.15
20.6 SYSTEM EFFECT 20.17
Mechanism of System Effect 20.17
Inlet System Effect 20.18
Inlet System Effect Loss 20.19
Inlet System Effect Loss Coefficient 20.19
Outlet System Effect 20.20
Outlet System Effect Loss
Coefficient 20.22
Selecting Fan Considering System
Effect Losses 20.23
20.7 COMBINATION OF FAN-DUCT
SYSTEMS 20.24
Two Fan-Duct Systems
Connected in Series 20.25
Fans Combined in Parallel and
Connected in Series with a Duct
System 20.26
Two Parallel Fan-Duct Systems
Connected with Another
Duct System 20.28
20.8 MODULATION OF THE FAN-DUCT
SYSTEM 20.31
Modulation Curve 20.31
Modulation of Fan-Duct Systems 20.33
20.9 CLASSIFICATION OF AIR
SYSTEMS 20.39
20.10 CONSTANT-VOLUME SYSTEMS 20.40
System Characteristics 20.40
Energy per Unit Volume Flow 20.41
20.11 AIR CONDITIONING
PROCESSES 20.41
Sensible Heat Ratio 20.41
20.12 SPACE CONDITIONING AND
SENSIBLE COOLING AND HEATING
PROCESSES 20.43
Space Conditioning Process 20.43
Sensible Heating and Cooling
Processes 20.44
20.13 HUMIDIFYING PROCESSES 20.45
Steam Injection and Heating
Element Humidifier 20.45
Air Washer 20.46
Oversaturation 20.46
20.14 COOLING AND DEHUMIDIFYING
PROCESS 20.46
20.15 ADIABATIC MIXING AND BYPASS
MIXING PROCESSES 20.50
Two-Stream Adiabatic Mixing
Process 20.50
Bypass Mixing Process 20.52
20.16 SINGLE-ZONE, CONSTANT-VOLUME
SYSTEMS—COOLING
MODE OPERATION 20.53
Air Conditioning Cycle 20.53
Cooling Mode Operation in
Summer 20.53
Cooling Mode Operation in Winter
without Space Humidity Control 20.56
Cooling Mode Operation in Winter
with Space Humidity Control 20.57
Part-Load Operation and Controls 20.58
Outdoor Ventilation Air and
Exhaust Fans 20.58
20.17 SUPPLY VOLUME FLOW RATE 20.59
Based on Space Cooling and Heating
Load 20.59
Based on Requirements Other Than
Cooling Load 20.60
Rated Volume Flow of Supply and
Return Fans 20.61
20.1