دانلود کتاب Industrial Ventilation Design Guidebook: Volume 1: Fundamentals

فهرست مطالب :

Industrial Ventilation Design Guidebook Copyright Contents List of Contributors Contributors of previous edition* Preface Acknowledgements 1 Introduction 1.1 Goals/benefits 1.1.1 Goals 1.1.2 Benefits 1.2 History and state of the art 1.3 Industrial Ventilation Design Guidebook—IVDGB (2001) 1.4 Industrial Ventilation Design Guidebook—IVDGB (2020) 1.5 Future directions and opportunities 1.5.1 Background 1.5.2 China 1.5.3 Europe 1.5.4 North America (example given is based on Ontario, Canada) 1.5.5 Japan 1.5.5.1 The Basic Environmental Law 1.5.5.2 Air Pollution Control Law 1.5.5.3 The Building Standard Law 1.5.5.4 Heating, Air-Conditioning and Sanitary Standard 102 Ventilation Standard 1.5.5.5 Activity of Society of Heating, Air-Conditioning, and Sanitary Engineers of Japan 1.5.5.6 Activity of other academic societies 1.6 Opportunities References 2 Terminology 2.1 Main definitions 2.2 Zones 2.3 Industrial air-conditioning systems 2.4 Local exhaust ventilation systems 2.5 Gas-cleaning systems 2.6 Definitions of types of air 3 Industrial ventilation design method 3.1 General 3.2 Design methodology description 3.2.1 Explanations of the design process 3.2.2 Explanations of back couplings (BC) in the design process 3.3 Determination of ventilation airflow rate 3.3.1 Calculation of ventilation airflow rate 3.3.2 Heat load 3.3.3 Moisture load 3.3.4 Emission rate of pollutants 3.3.5 Calculation of air balance and heat balance 3.4 Design for ventilation system 3.4.1 Principle of ventilation design 3.4.2 Mixing ventilation 3.4.3 Displacement ventilation 3.4.4 Attachment ventilation 3.5 Local ventilation 3.5.1 Introduction 3.5.2 Design principle of local exhaust system 3.5.3 Composition of local exhaust system 3.6 Industrial ventilation duct design 3.6.1 Duct losses 3.6.2 Low resistance components 3.6.3 Considerations about duct design 3.6.4 Calculation of duct design 3.6.5 Duct design methods References Further reading 4 Physical fundamentals 4.1 Fluid flow 4.1.1 Fluid properties 4.1.1.1 Fluid classification Ideal fluid Real fluid Incompressible fluid Compressible fluid Flow classification Steady flow Unsteady flow Uniform flow Nonuniform flow Laminar flow Transitional flow Turbulent flow Rotational flow Irrotational flow Path line Streamline Stream tube Stream surface Streak line One-, two-, or three-dimensional flow 4.1.1.2 Properties of fluids Density Specific weight Specific gravity Plastic fluids Pseudoplastic fluids Dilatant fluids Surface tension Viscosity 4.1.2 Constants for water 4.1.3 Constants for gases 4.1.4 Properties of air and water vapor 4.1.5 Liquid flow 4.1.5.1 Energy equation 4.1.5.2 Viscous flow 4.1.5.3 Laminar and turbulent flow Laminar tube flow Turbulent flow Surface roughness 4.1.5.4 Single resistances in a tube flow 4.1.5.5 Pressure loss in gas and steam pipes 4.1.5.6 Dimensioning of a duct with liquid flow 4.2 State values of humid air—Mollier diagrams and their applications 4.2.1 Properties of air and other gases 4.2.2 Fundamentals 4.2.3 Water vapor pressure in the presence of air 4.2.4 Vapor pressure of water and ice and calculation of humid air state values 4.2.5 Construction of a Mollier diagram 4.2.6 Determination of air humidity 4.2.7 State changes of humid air 4.2.8 Example of cooling tower dimensioning 4.3 Heat and mass transfer 4.3.1 Different forms of heat transfer 4.3.1.1 Conduction 4.3.1.2 Convection 4.3.1.3 Radiation 4.3.2 Analogy with the theory of electricity 4.3.3 Heat conduction 4.3.3.1 General heat conduction equation 4.3.3.2 One-dimensional steady-state heat conduction Infinite plate Axial-symmetric case 4.3.4 Heat convection 4.3.4.1 Calculation using the correlation formulas 4.3.4.2 Forced convection 4.3.4.3 Free convection Flow up a vertical wall Flow upward on a horizontal plane Flow past a horizontal pipe 4.3.5 Thermal radiation 4.3.5.1 Planck’s law of radiation 4.3.5.2 Emissivity and absorption 4.3.5.3 Lambert’s cosine law 4.3.5.4 Thermal radiation inside a vacuum (without gas) 4.3.6 Mass transfer coefficient 4.3.7 Heat and mass transfer differential equations in the boundary layer and the corresponding analogy 4.3.8 Diffusion through a porous material 4.3.9 Example of drying process calculation 4.3.10 Evaporation from a multicomponent liquid system 4.4 Water properties and treatment 4.4.1 Introduction 4.4.2 Common water impurities 4.4.2.1 Heavy metals 4.4.3 Cooling water systems 4.4.3.1 Open recirculation Advantages Disadvantages 4.4.3.2 Closed recirculation Advantages Disadvantages 4.4.3.3 Once-through system Advantages Disadvantages 4.4.4 Water treatment 4.4.4.1 Methods of feedwater treatment Sedimentation Oxidation Filtration Softening Deaeration Oxygen scavenging Scale control Sludge Foam Condensate Biological factors 4.4.4.2 Separation techniques Separation of a liquid from a solid Separation of a solid from a liquid Design considerations 4.4.4.3 Heat transfer fluids Reference 5 Physiological and toxicological considerations 5.1 Thermal comfort 5.1.1 Introduction 5.1.1.1 Why one is comfortable? What affects our comfort? 5.1.2 Primary factors 5.1.2.1 Body temperature 5.1.2.2 Metabolism 5.1.2.3 Physiological temperature regulation 5.1.3 Body control temperatures 5.1.3.1 Thermal sensation 5.1.3.2 Body temperature sensors 5.1.4 Clothing 5.1.4.1 Heat and moisture transfer in clothing 5.1.4.2 Thermal insulation 5.1.4.3 Effects of moisture on clothing 5.1.4.4 Effect of chairs on clothing insulation 5.1.4.5 Effect of walking and air movement on clothing insulation 5.1.5 Comfort zones 5.1.5.1 Warm discomfort and skin moisture 5.1.5.2 Indoor humidity 5.1.6 Spatial and temporal nonuniformity 5.1.7 Thermal radiation and operative temperature 5.1.8 Future perspectives 5.2 Human respiratory tract physiology 5.2.1 Introduction 5.2.2 Anatomical overview 5.2.2.1 Extrathoracic airway anatomy 5.2.2.2 Central and pulmonary airway anatomy 5.2.2.3 Airway wall anatomy Airway surface liquid Airway epithelial cell types 5.2.2.4 Airway vasculature 5.2.3 Ventilation patterns 5.2.3.1 Breathing mechanics 5.2.3.2 Measurement of pulmonary gas exchange 5.2.3.3 Static and dynamic lung volumes 5.2.3.4 Bronchial hyperresponsiveness (hyperreactivity) 5.2.3.5 Intraairway airflow patterns 5.2.4 Mucociliary clearance 5.2.4.1 Ciliary location 5.2.4.2 Ciliary structure 5.2.4.3 Relationship of ciliary motion to mucus movement 5.2.5 Airway heat and water vapor transport 5.2.5.1 Longitudinal and radial temperature/humidity gradients 5.2.5.2 Role of airway heat and water vapor exchange in disease and injury 5.2.6 Endogenous ammonia production 5.2.7 Respiratory defense mechanisms 5.2.7.1 Vapor-phase neutralization 5.2.7.2 Aerosol defense Particle deposition Acid aerosol neutralization Mucociliary escalator Exhaled nitric oxide 5.3 Toxicity and risks induced by occupational exposure to chemical compounds 5.3.1 Introduction and background 5.3.1.1 Health hazards of occupational exposure 5.3.1.2 Epidemiology Cross-sectional studies Cohort Studies Case–control studies 5.3.1.3 Classifications of toxicology 5.3.1.4 Industrial toxicology, hygiene, and occupational medicine Poisoning incidents in the workplace 5.3.1.5 Concept of risks 5.3.2 Exposure to chemical substances 5.3.2.1 Characterization of exposures Indoor and outdoor exposure to pollutants Characteristics of industrial processes 5.3.2.2 Exposure routes Inhalational exposure Dermal exposure Oral exposure 5.3.2.3 Physicochemical determinants of exposure Water solubility The importance of pH and pKa Lipid solubility Blood solubility Partition coefficients Vapor pressure Particle size 5.3.2.4 Physiological determinants of exposure Inhalational exposure Dermal exposure 5.3.3 Kinetics of chemical compounds 5.3.3.1 Absorption Entry of particles into the body 5.3.3.2 Distribution Special considerations 5.3.3.3 Metabolism 5.3.3.4 Excretion 5.3.3.5 Movements of chemical compounds in the body One-compartment model Two-compartment model Saturation of Elimination Physiologically based toxicokinetic models 5.3.4 Toxic effects of chemicals 5.3.4.1 The nature of toxic effects 5.3.4.2 Joint effects of chemicals 5.3.4.3 Mechanisms of toxicity Receptor-mediated toxicity Effects on excitable membranes Effects on cellular energy metabolism Disturbances in cellular calcium metabolism Nitric oxide Immunological responses and sensitization Necrotic and apoptotic cell death Binding to cellular macromolecules Genotoxicity 5.3.4.4 Target organs Organs as targets of chemical compounds Toxicity to the central and peripheral nervous systems Eye toxicity Pulmonary toxicity Cardiovascular toxicity Mechanisms of cardiotoxicity Liver toxicity Kidney toxicity Reproductive toxicity Toxicity to blood and blood-forming tissues Toxicity to the skin Allergies 5.3.4.5 Developmental toxicity Mechanisms of chemical teratogenesis Teratogens and developmental toxicants 5.3.4.6 Carcinogens and mutagens Mechanisms of chemical carcinogenesis Transplacental carcinogenesis 5.3.5 Exposure assessment 5.3.5.1 Determination of airborne concentrations 5.3.5.2 Biological monitoring 5.3.5.3 Biomarkers 5.3.6 Toxicity, risks, and risk assessment 5.3.6.1 Phases of risk assessment 5.3.6.2 The significance of health risks of chemical compounds 5.3.6.3 Perception of risks by experts and the general population 5.3.6.4 Special considerations 5.3.6.5 Important chemical carcinogens 5.3.6.6 Future perspectives 5.4 Ventilation noise—characteristics, effects, and suggested counter-measures 5.4.1 Occurrence 5.4.2 Ventilation noise as an environmental problem 5.4.3 Physical characteristics 5.4.4 Noise generation 5.4.4.1 Fan noise 5.4.4.2 Flow noise 5.4.4.3 Noise simulation 5.4.4.4 Noise calculation rules for duct components 5.4.5 Effects on humans 5.4.5.1 Influence on disturbance and working performance 5.4.5.2 Influence due to spectral distribution 5.4.5.3 Influence due to exposure period 5.4.5.4 Influence due to time fluctuations 5.4.5.5 Effects on hearing 5.4.6 Measures 5.4.7 Elimination of different ventilation noise sources 5.4.7.1 The fan 5.4.7.2 The fan room 5.4.7.3 The fan ducts 5.4.7.4 The supply and exhaust air terminals 5.4.8 Exposure limits 5.5 Glossary References 6 Target levels 6.1 Overview of target levels 6.1.1 Introduction 6.1.2 Factors affecting the target levels 6.1.2.1 Laws and regulations 6.1.2.2 Trade standards 6.1.2.3 Nonbinding standards 6.1.2.4 Architectural type 6.1.3 Setting principles of target level 6.1.3.1 Principle of comprehensiveness 6.1.3.2 Principle of readjustment 6.1.3.3 Principle of integrity 6.1.4 Use of target levels 6.1.4.1 Step 1: Musts 6.1.4.2 Step 2: Needs 6.1.4.3 Step 3: Target levels 6.1.4.4 Step 4: Design conditions 6.1.4.5 Step 5: Reliability 6.1.5 Combination of target levels and design methodology 6.1.5.1 Given data 6.1.5.2 Process description 6.1.5.3 Building layout and structures 6.1.5.4 Target level assessment 6.1.5.5 Source description 6.1.5.6 Calculation of local loads 6.1.5.7 Calculation of total building loads 6.1.5.8 Selection of system 6.1.5.9 Detailed design 6.2 Occupational exposure limit 6.2.1 Introduction 6.2.2 Types of occupational exposure limits 6.2.3 Setting occupational exposure limits 6.2.4 Occupational exposure assessment 6.3 Target level of thermal environment 6.3.1 Introduction 6.3.1.1 Metabolic rate 6.3.1.2 Clothing thermal insulation 6.3.1.3 Mean radiant temperature 6.3.2 Thermal environment assessment 6.3.2.1 Cold stress Definition 6.3.2.2 Heat stress and heat strain Definition Assessment 6.3.2.3 Thermal comfort Environmental factors affecting comfort Operative temperature Humidity threshold Air speed Asymmetric thermal radiation Draft sensation Vertical air temperature difference Warm or cold floors Personal factors affecting comfort Age Sex Acclimation Prediction of thermal comfort Predicted mean vote Predicted percent dissatisfied 6.4 Target levels for industrial air quality 6.4.1 Introduction 6.4.2 Grounds for assessing target levels for industrial air quality References 7 Principles of air and contaminant movement inside and around buildings 7.1 Introduction 7.2 Contaminant sources 7.2.1 Classification 7.2.1.1 External sources 7.2.1.2 HVAC system 7.2.1.3 Internal sources 7.2.2 Nonbuoyant contaminant sources 7.2.2.1 Contaminant emission by a process 7.2.2.2 Gas and vapor emission through looseness in process equipment and pipelines 7.2.2.3 Gas and vapor emission processes from an open liquid face 7.2.3 Emission from heat sources 7.2.3.1 Sensible heat sources 7.2.3.2 Heat gain from process equipment 7.2.3.3 Heat gain from lighting 7.2.3.4 Heat gain from equipment operated by electric motors 7.2.3.5 Heat loss/gain for heating or cooling materials and parts brought into or taken out of the space 7.2.3.6 Heat load from molten metal cooling 7.2.4 Sources of dust 7.2.5 Sources of moisture emission 7.2.5.1 Moisture diffusion through the building envelope 7.2.5.2 Evaporation from wet surfaces and open tanks 7.2.5.3 Moisture from air leaks through cracks and apertures 7.2.5.4 Moisture from personnel 7.2.5.5 Moisture from combustion 7.2.6 Source of mist emission 7.2.6.1 Mechanism of mist generation 7.2.6.2 Vapor condensation 7.2.6.3 Bubble burst 7.2.6.4 Source characteristics 7.2.6.5 Droplet evaporation and movement 7.2.7 Explosive gases, vapors, and dust mixtures 7.2.8 Identification of contaminant sources 7.2.8.1 Inverse identification of multiple temporal release rates 7.2.8.2 Inverse identification of multiple pollutant source locations 7.2.8.3 Solution procedure 7.3 Transport mechanism of contaminant in ventilated space 7.3.1 Factors influencing room airflow 7.3.2 Typical airflow patterns 7.3.2.1 Airflow dominated by supply jets 7.3.2.2 Airflow dominated by thermal plumes 7.3.2.3 Unidirectional flow 7.3.2.4 Spiral vortex flow 7.3.2.5 Airflow created by exhausts 7.3.3 Quantitative effects of various factors on contaminant distribution 7.3.3.1 Transient accessibility of supply air 7.3.3.2 Transient accessibility of contaminant source 7.3.3.3 Transient accessibility of initial condition 7.3.4 Analytical expression for transient transport of passive contaminant 7.3.4.1 Contribution from supply air 7.3.4.2 Contribution from contaminant source 7.3.4.3 Contribution from initial condition 7.3.4.4 Expression for transient concentration of contaminant 7.4 Air jets 7.4.1 Introduction 7.4.2 Classification 7.4.3 Isothermal free jet 7.4.3.1 Zones in a jet 7.4.3.2 Velocity distribution in jet cross-section within Zone III 7.4.3.3 Centerline velocity in Zone III Compact jet Linear jet Radial jet 7.4.3.4 Universal equations for velocity computation along jets supplied from outlets with finite dimensions 7.4.3.5 Jet throw 7.4.3.6 Entrainment ratio 7.4.4 Nonisothermal free jets 7.4.4.1 Criteria for nonisothermal jets 7.4.4.2 Temperature profile distribution in a jet 7.4.4.3 Centerline temperature differential in a horizontally supplied jet Compact jet Linear jet Radial jet 7.4.4.4 Universal equations for temperature difference computation along jets supplied from outlets with finite dimensions Velocities and temperatures in vertical nonisothermal jets Nonisothermal jet throw Trajectory of horizontal and inclined jets 7.4.4.5 Jet attachment 7.4.4.6 Jet separation 7.4.5 Jets in confined spaces 7.4.5.1 General description of confined flow 7.4.5.2 Experimental studies of isothermal horizontal jets in confined spaces: airflow pattern, throw, and velocities Effect of jet proximity to the ceiling Effect of ceiling beams or obstructions in the jet zone 7.4.5.3 Analytical studies 7.4.5.4 Experimental studies of horizontal heated and cooled air supply in confined spaces 7.4.5.5 Computational fluid dynamics simulation of heated and cooled air supply in confined spaces 7.4.5.6 The effect of confinement on inclined air jets 7.4.5.7 Air supply with vertical jets 7.4.5.8 Airflow patterns and airflow in occupied zone 7.4.6 Jet interaction 7.4.6.1 Interaction of parallel jets 7.4.6.2 Interaction of jets supplied from opposite directions 7.4.6.3 Interaction of coaxial jets Interaction of the free isothermal main stream and horizontal directing jets Interaction of the confined isothermal main stream with horizontal directing jets Interaction of a nonisothermal main stream with horizontal directing jets 7.4.6.4 Interaction of jets supplied at an angle to each other Interaction of a free isothermal main stream with directing jets supplied at a right angle to the main stream 7.4.7 Applications of air jets 7.4.8 Effectiveness of air jet to different areas 7.5 Plumes 7.5.1 Natural convection flows 7.5.2 Nonconfined and nonstratified environments 7.5.2.1 Plumes from point and line sources 7.5.2.2 Convection flow along vertical surfaces 7.5.2.3 Convection flow from horizontal surfaces 7.5.2.4 Plumes from extended sources 7.5.3 Plume interaction 7.5.4 Plumes in confined spaces 7.5.5 Plumes in rooms with temperature stratification 7.5.5.1 Point source 7.5.5.2 Line source 7.5.6 Effect of plumes on transport of contaminant 7.6 Airflow near exhausts 7.6.1 Introduction 7.6.2 Air movement near sinks 7.6.2.1 Theoretical considerations 7.6.2.2 Air movement near a point sink 7.6.2.3 Air movement near a linear sink 7.6.2.4 Air movement near sinks with finite dimensions 7.7 Air curtains 7.7.1 Introduction 7.7.2 Types of air curtains 7.7.2.1 Air curtains with heated indoor air 7.7.2.2 Air curtains with unheated indoor air 7.7.2.3 Air curtains with unheated outdoor air 7.7.2.4 Combined air curtains with indoor air 7.7.3 Applications of air curtains 7.7.3.1 Air curtains for cooled rooms 7.7.3.2 Air curtains for gates with long passages 7.7.3.3 Air curtains for process equipment 7.7.3.4 Air curtains for tunnels 7.7.3.5 Air curtains for relics preservation 7.7.3.6 Air curtains for aerodynamic noise reduction 7.7.3.7 Air curtains for cleanrooms 7.7.3.8 Air curtains for antiinsect barrier 7.7.4 Principle of calculation 7.7.5 Operation of the air curtain 7.7.6 Design of an air curtain device 7.7.6.1 The task 7.7.6.2 Data 7.7.6.3 Pressure distribution in the building 7.7.6.4 Calculation of the parameters of the air curtain 7.7.7 Effect of air curtain on transport of contaminant 7.8 Air movement around buildings and through a building envelope 7.8.1 Airflow around buildings 7.8.1.1 General features of airflow around buildings 7.8.1.2 Building surface wind pressures Wind speed Surface pressure coefficient 7.8.1.3 Contaminant transport around buildings 7.8.2 Infiltration and exfiltration 7.8.2.1 Pressure difference due to stack effect 7.8.2.2 Wind pressure 7.8.2.3 Effect of ventilation system performance 7.8.2.4 Combined effect of gravity forces, wind, and mechanical ventilation 7.8.2.5 Calculation methods 7.8.3 Airflow through large openings and gates 7.8.4 Principles of natural ventilation and “pumping mechanism” 7.8.4.1 Design principles of natural ventilation 7.8.4.2 Pumping flow mechanism—a special wind driven ventilation 7.8.5 Air and contaminant movement between building zones 7.8.6 Air and contaminant movement in neighborhood scale and urban scale 7.8.6.1 Ventilation in street canyon 7.8.6.2 Airflow within building arrays 7.8.6.3 Ventilation evaluation of building arrays Ventilation flow rate and air change rate Pollutant removal rate Local mean age of air and air exchange efficiency References Further reading 8 Room air conditioning 8.1 Introduction 8.2 Basis for air conditioning design 8.2.1 Industrial process description 8.2.1.1 Stages of the industrial production process 8.2.1.2 Space demands for the production process 8.2.2 Requirements for indoor environment 8.2.2.1 Air conditioning demands for human occupancy 8.2.2.2 Conditioning demands other than for human occupants 8.2.3 Architectural design for an industrial enclosure 8.2.4 Worker involvement in the production process 8.2.5 Load calculation 8.2.5.1 Heat and contaminant emission 8.2.5.2 Room envelope characterization 8.2.6 Characterization of room airflow and thermal conditions based on industrial production process and envelope 8.2.6.1 Design winter conditions 8.2.6.2 Design summer conditions 8.2.7 Analyses and actions to be considered prior to performing room air conditioning design 8.3 Effective and efficient ventilation 8.3.1 Ventilation efficiency indices 8.3.2 Contaminant removal effectiveness 8.3.3 Contaminant removal efficiency 8.3.4 Air exchange efficiency 8.3.5 Air distribution performance index 8.4 Room air conditioning strategies 8.4.1 Introduction 8.4.2 Classification for room air conditioning strategies 8.4.3 Piston strategy 8.4.3.1 Description 8.4.3.2 Advantages and disadvantages 8.4.3.3 Design criteria 8.4.3.4 Application 8.4.4 Stratification strategy 8.4.4.1 Description 8.4.4.2 Advantages and disadvantages 8.4.4.3 Design criteria 8.4.4.4 Application 8.4.5 Zoning strategy 8.4.5.1 Description 8.4.5.2 Advantages and disadvantages 8.4.5.3 Design criteria 8.4.5.4 Application 8.4.6 Mixing strategy 8.4.6.1 Description 8.4.6.2 Advantages and disadvantages 8.4.6.3 Design criteria 8.4.6.4 Application 8.4.7 Application of the strategy in system selection 8.4.8 Summary 8.5 Air distribution methods and dimensioning 8.5.1 Selection of air supply method 8.5.2 Mixing air distribution 8.5.2.1 Penetration of horizontal air jets Room length Room width 8.5.2.2 Reverse flow Short rooms Long rooms 8.5.3 Piston flow 8.5.3.1 Filter mat ceilings 8.5.3.2 Perforated sheet ceilings 8.5.3.3 Thermal instabilities in piston flows 8.5.4 Displacement flow 8.5.4.1 Warm contaminants 8.5.4.2 Cold contaminants 8.5.5 Zonal air distribution 8.5.5.1 Design requirements for achieving the zoning strategy 8.5.5.2 Two-zone model for zoning strategy 8.5.5.3 Characteristics of the zoning strategy 8.6 Location of general exhaust 8.6.1 Exhausts in nonstratified room air 8.6.2 Exhaust of buoyant contaminants 8.6.2.1 Exhaust of warm fumes 8.6.2.2 Exhaust of cold fumes 8.6.2.3 Exhaust of fumes with unpredictable buoyancy 8.6.3 Exhausts in stratified room air 8.6.4 Location of general exhaust to create displacement flow 8.7 Air recirculation 8.7.1 Introduction 8.7.2 Different recirculating systems 8.7.3 Central recirculation system 8.7.4 Local recirculation 8.7.5 Conclusion 8.8 Heating of industrial premises 8.8.1 General 8.8.2 The heating power demand 8.8.3 The heating energy demand 8.8.4 Radiant heating 8.8.4.1 Radiant temperature 8.8.4.2 Radiant heating panels heated by water 8.8.5 Hot air blowers 8.8.6 Air jets 8.8.7 Floor heating 8.8.7.1 General 8.8.7.2 Surface temperature and heat emission References 9 Air-handling processes 9.1 Introduction 9.1.1 Scope and purpose 9.1.2 Aims of an air-handling system, including the unit and ductwork 9.2 Air filters 9.2.1 Why air filters? 9.2.1.1 Ventilation system protection 9.2.1.2 Hygiene requirement 9.2.2 Atmospheric air and dust 9.2.2.1 Size of particles 9.2.2.2 Number of particles 9.2.2.3 Other aspects Allergy Carcinogenic potential of pollutants Odors/gases 9.2.3 Filters and test methods 9.2.3.1 Test methods 9.2.3.2 Classification of coarse and fine filters 9.2.3.3 EPA, HEPA, and ULPA Filters 9.2.3.4 Chemical filters 9.2.4 Filters in operation 9.2.4.1 Outdoor air quality and desired supply air quality 9.2.4.2 Average pressure loss 9.2.4.3 Energy consumption 9.2.4.4 Lifetime 9.2.4.5 Filter replacement 9.2.5 Life-cycle issues 9.2.5.1 Environment: life-cycle analysis 9.2.5.2 Life-cycle cost 9.2.6 Summary 9.3 Heat exchangers and heat-recovery units 9.3.1 General theory of heat exchangers 9.3.1.1 Introduction 9.3.1.2 Effectiveness–number of transfer units method and counterflow heat exchanger 9.3.1.3 Logarithmic mean temperature difference 9.3.2 Plate fin-and-tube heat exchangers 9.3.2.1 Introduction 9.3.2.2 Annular fins 9.3.2.3 Fin efficiency 9.3.2.4 The convective heat transfer coefficient between the plate and flowing air 9.3.2.5 Liquid-side conductance and total conductance of heat exchanger 9.3.3 Additional considerations of using heat exchangers and heat-recovery units 9.4 Air-handling processes 9.4.1 Air-heating equipment 9.4.1.1 Introduction 9.4.1.2 Selection 9.4.1.3 Air-heating coils 9.4.1.4 Heat requirements 9.4.1.5 Low-temperature hot-water heating coils 9.4.1.6 Steam-heated coils 9.4.1.7 Electric air heaters 9.4.1.8 Direct-fired air heaters 9.4.1.9 Gas-fired heaters 9.4.1.10 Oil-fired heaters 9.4.1.11 Solid fuel–fired heaters 9.4.1.12 Air-heating-coil selection factors 9.4.1.13 Selection of direct-fired air heaters Flued heaters 9.4.2 Humidification and dehumidification 9.4.2.1 Introduction 9.4.2.2 Humidifier types Humidifiers complete with water storage Spray-type humidifier Pan-type humidifier Mechanical pan Steam-generating pan Humidifiers without water storage Spinning-disk humidifier Steam jet Ultrasonic atomization Air washer 9.4.2.3 Selection factors Dehumidification Compression Refrigeration Chemical dehumidification 9.4.2.4 Summary 9.4.3 Air distribution 9.4.3.1 Introduction Ventilation 9.4.3.2 Ventilation methods Natural ventilation Mechanical extract–induced input Mechanical input–forced extract Mechanical input–mechanical extract 9.4.3.3 Methods of air distribution Upward ventilation (displacement) Downward systems Mixed upward–downward system 9.4.3.4 Air-handling equations Air mixing For mass flow For moisture content For enthalpy For temperature Total room air movement Moisture content 9.5 Fans 9.5.1 General 9.5.1.1 Fan types Propeller Axial fan Centrifugal fan Airfoil, backward curved Radial blade, straight paddle blade Forward-curved blade, centrifugal 9.5.2 Centrifugal fan 9.5.3 Axial fans 9.5.4 Effect of speed of revolution 9.5.5 Fan and duct network 9.5.6 Series fan connection 9.5.7 Fan volume flow regulation 9.6 Automatic control of HVAC systems 9.6.1 Methods for automation control 9.6.2 Main types of control equipment and automation level 9.6.3 General technical requirements 9.6.4 Automation equipment and instrumentation 9.6.5 Process 9.6.6 Controller 9.6.7 The choice of controllers 9.6.8 Sensors 9.6.9 Placing of sensors in HVAC systems 9.6.10 Changing speed by using frequency converters 9.6.11 Building the control station 9.7 Air distribution system, ductwork 9.7.1 Friction loss calculation 9.7.1.1 The surface roughness factor ϵ Hydraulic diameter Pressure loss due to local resistance 9.7.2 Design methods 9.7.2.1 Boundary conditions 9.7.3 Thermal losses by transmission 9.7.3.1 Circular ducts 9.7.3.2 Rectangular ducts 9.7.4 Air leakage from ductwork 9.7.4.1 Leakages of air distribution systems 9.7.5 Ductwork components for safety in ventilation 9.7.5.1 Fire dampers and smoke control dampers Fire dampers Smoke control dampers 9.7.5.2 Fire-resisting ducts and smoke control ducts Fire-resisting ducts Smoke control ducts 9.7.5.3 Hazardous areas Zone classification Zone classification 9.7.5.4 Pressure relief dampers 9.8 Sound reduction in air-handling systems 9.8.1 Basic concepts 9.8.2 Free-field noise transmission 9.8.3 Criteria for acceptable air-handling units and HVAC system noise levels 9.9 Fundamentals of energy system optimization in industrial buildings 9.9.1 Design aspects of energy-efficient systems 9.10 Special considerations and system design aspects 9.10.1 Aspects related to the quality of extract or exhaust air 9.10.1.1 Examples of ETA and EHA classification applications—reuse of extract air Distances and locations of openings Pressure conditions 9.10.2 Other questions References Appendix 1 Physical Factors, Units, Definitions and References Dimensionless numbers Archimedes number Colburn j-factor Condensation number Euler number Fraude number Graetz number Grashof number Knudsen number Lewis number Mach number Nusselt number Peclet number Prandtl number Reynolds number Richardson number Schmidt number Sherwood number Stanton number Stokes number Glossary A B C D E F G H I J K L M N O P Q R S T U V W X Y Z International and National Bodies Further reading Index