Applied Building Physics
Beschreibung
Bad experiences with construction quality, the energy crises of 1973 and 1979,complaints about 'sick buildings', thermal, acoustical, visual and olfactory discomfort, the need for good air quality, the move towards more sustainability - all these have accelerated the development of a field that, for a long time, was hardly more than an academic exercise: building physics. The discipline embraces domains such as heat and mass transfer, building acoustics, lighting, indoor environmental quality and energy efficiency. In some countries, fire safety is also included. Through the application of physical knowledge and its combination with information coming from other disciplines, the field helps to understand the physical phenomena governing building parts, building envelope, whole building and built environment performance, although for the last the wording 'urban physics' is used. Building physics has a real impact on performance-based building design. This volume on 'Applied Building Physics' discusses the heat, air and moisture performance metrics that affect building design, construction and retrofitting.
Weitere Details
Weitere Ausgaben
Andere Ausgaben
Person
He authored and co-authored some 70 peer reviewed journal and 170 conference papers about the research done at the unit, helped man-aging hundreds of building damage cases and acted as coordinator of the CIB W40 working group on Heat and Mass Transfer in Buildings from 1983 till 1993. Between 1986 and 2008, he was operating agent of the Annexes 14, 24, 32 and 41 of the International Energy Agency`s EXCO on Energy in Buildings and Communities. He is a fellow of the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE).
Inhalt
0 Introduction 1
0.1 Subject of the book 1
0.2 Building physics vs. applied building physics 1
0.3 Units and symbols 2
Further reading 5
1 Outdoor and indoor ambient conditions 7
1.1 Overview 7
1.2 Outdoors 8
1.2.1 Air temperature 9
1.2.2 Solar radiation 12
1.2.2.1 Beam radiation 14
1.2.2.2 Diffuse radiation 16
1.2.2.3 Reflected radiation 17
1.2.2.4 Total radiation 17
1.2.3 Longwave radiation 18
1.2.4 Relative humidity and (partial water) vapour pressure 22
1.2.5 Wind 23
1.2.5.1 Wind speed 24
1.2.5.2 Wind pressure 24
1.2.6 Precipitation and wind-driven rain 26
1.2.6.1 Precipitation 27
1.2.6.2 Wind-driven rain 28
1.2.7 Microclimates around buildings 30
1.2.8 Standardized outdoor climate data 31
1.2.8.1 Design temperature 31
1.2.8.2 Reference years 31
1.2.8.3 Very hot summer, very cold winter day 31
1.2.8.4 Moisture reference years 31
1.2.8.5 Equivalent temperature for condensation and drying 34
1.2.8.6 Monthly mean vapour pressure outdoors 37
1.3 Indoors 37
1.3.1 Air temperatures 37
1.3.1.1 In general 37
1.3.1.2 Measured data 38
1.3.2 Relative humidity and vapour pressure 41
1.3.2.1 Vapour release indoors 41
1.3.2.2 Measured data 44
1.3.2.3 Indoor climate classes 47
1.3.3 Indoor/outdoor air pressure differentials 50
Further reading 51
2 Performance metrics and arrays 54
2.1 Definitions 54
2.2 Functional demands 54
2.3 Performance requirements 54
2.4 A short history 55
2.5 Performance arrays 56
2.5.1 Overview 56
2.5.1.1 The built environment 56
2.5.1.2 Whole buildings and building assemblies 57
2.5.2 In detail 57
2.5.2.1 Functionality 57
2.5.2.2 Structural adequacy 57
2.5.2.3 Building physics related quality 60
2.5.2.4 Fire safety 60
2.5.2.5 Durability 61
2.5.2.6 Maintenance 61
Further reading 62
3 Whole building level 63
3.1 Thermal comfort 63
3.1.1 General concepts 63
3.1.2 Physiological basis 63
3.1.2.1 Exothermic 63
3.1.2.2 Homoeothermic 65
3.1.2.3 Autonomic control system 65
3.1.3 Steady state thermal comfort, the physiology based approach 66
3.1.3.1 Clothing 66
3.1.3.2 Heat flow between body and ambient 66
3.1.3.3 Comfort equations 68
3.1.3.4 Comfort parameters and variables 69
3.1.3.5 Thermally equivalent environments and comfort temperatures 69
3.1.3.6 Comfort appreciation 71
3.1.4 Steady state thermal comfort, the adaptive model 72
3.1.5 Thermal comfort under non-uniform and under transient conditions 74
3.1.5.1 Refined body model 74
3.1.5.2 Local discomfort 76
3.1.5.3 Drifts and ramps 78
3.1.6 Standard-based comfort requirements 80
3.1.7 Comfort related enclosure performance 81
3.2 Health and indoor environmental quality 83
3.2.1 In general 83
3.2.2 Health 84
3.2.3 Definitions 85
3.2.4 Relation between pollution outdoor and indoors 85
3.2.5 Process-related contaminants 86
3.2.5.1 Dust, vapour, smoke, mist and gaseous clouds 86
3.2.5.2 Fibres 86
3.2.5.3 Ozone 87
3.2.6 Building, insulation and finishing material related contaminants 87
3.2.6.1 (Semi) volatile organic compounds ((S)VOCs) 87
3.2.6.2 Formaldehyde (HCHO) 88
3.2.6.3 Phthalates 89
3.2.6.4 Pentachlorinephenols 89
3.2.7 Soil-related radon as contaminant 89
3.2.8 Combustion related contaminants 91
3.2.8.1 Carbon monoxide 91
3.2.8.2 Nitrous dioxide (NO2) 91
3.2.9 Bio-germs 92
3.2.9.1 Viruses 92
3.2.9.2 Bacteria 92
3.2.9.3 Mould 92
3.2.9.4 Dust mites 95
3.2.9.5 Insects 95
3.2.9.6 Rodents 96
3.2.9.7 Pets 96
3.2.10 Human related contaminants 96
3.2.10.1 Carbon dioxide (CO2) 97
3.2.10.2 Water vapour 97
3.2.10.3 Bio-odours 97
3.2.10.4 Tobacco smoke 98
3.2.11 Perceived indoor air quality 99
3.2.11.1 Odour 99
3.2.11.2 Indoor air enthalpy 101
3.2.12 Sick building syndrome (SBS) 102
3.2.13 Contaminant control 103
3.2.13.1 Minimizing emission 103
3.2.13.2 Ventilation 103
3.2.13.3 Air cleaning and personal protective measures 109
3.3 Energy efficiency 110
3.3.1 In general 110
3.3.2 Some statistics 111
3.3.3 End energy use in buildings 112
3.3.3.1 Lighting and appliances 112
3.3.3.2 Domestic hot water 116
3.3.3.3 Space heating, cooling and air conditioning 116
3.3.4 Space heating 116
3.3.4.1 Terminology 116
3.3.4.2 Steady state heat balance at zone level 118
3.3.4.3 Whole building steady state heat balance 123
3.3.4.4 Heat gain utilization efficiency 123
3.3.4.5 Annual end use for heating 125
3.3.4.6 Protected volume as one zone 125
3.3.5 Residential buildings, parameters shaping the annual net heating demand 125
3.3.5.1 Overview 125
3.3.5.2 Outdoor climate 126
3.3.5.3 Building use 127
3.3.5.4 Building design and construction 135
3.3.6 Residential buildings, parameters fixing net cooling demand 144
3.3.7 Residential buildings, gross energy demand, end energy use 146
3.3.8 Residential buildings ranked in terms of energy efficiency 146
3.3.8.1 Insulated 146
3.3.8.2 Energy efficient 146
3.3.8.3 Low energy 147
3.3.8.4 Passive 147
3.3.8.5 Near zero energy 147
3.3.8.6 Net zero energy 147
3.3.8.7 Net plus energy 147
3.3.8.8 Energy autarkic 148
3.3.9 Non-residential buildings, net and gross demand, end and primary energy use 148
3.3.9.1 In general 148
3.3.9.2 School retrofits as an exemplary case 148
3.4 Durability 152
3.4.1 In general 152
3.4.2 Loads 153
3.4.3 Damage patterns 153
3.4.3.1 Decrease in thermal quality 153
3.4.3.2 Decrease in strength and stiffness 154
3.4.3.3 Stress, strain, deformation and cracking 154
3.4.3.4 Biological attack 158
3.4.3.5 Frost damage 160
3.4.3.6 Salt attack 163
3.4.3.7 Chemical attack 167
3.4.3.8 Corrosion 168
3.5 Economics 170
3.5.1 Total and net present value 170
3.5.2 Optimum insulation thickness 171
3.5.3 Whole building optimum 173
3.5.3.1 Methodology 173
3.5.3.2 Example 174
3.6 Sustainability 178
3.6.1 In general 178
3.6.2 Life cycle inventory and analysis 179
3.6.2.1 Definition 179
3.6.2.2 Some criteria 181
3.6.2.3 Whole energy use and minimal environmental load 181
3.6.2.4 Recycling 182
3.6.3 High performance buildings 182
Further reading 186
4 Envelope and fabric: heat, air and moisture metrics 195
4.1 Introduction 195
4.2 Airtightness 195
4.2.1 Air flow patterns 195
4.2.2 Performance requirements 197
4.2.2.1 Air infiltration and exfiltration 197
4.2.2.2 Inside air washing, wind washing and air looping 197
4.3 Thermal transmittance 198
4.3.1 Definitions 198
4.3.1.1 Opaque envelope assemblies above grade 198
4.3.1.2 Whole envelope 199
4.3.2 Basis for requirements 199
4.3.2.1 Envelope parts 199
4.3.2.2 Whole envelope 200
4.3.3 Examples of requirements 200
4.3.3.1 Envelope parts 200
4.3.3.2 Whole envelopes 200
4.4 Transient thermal response 204
4.4.1 Properties of importance 204
4.4.2 Performance requirements 206
4.4.3 Consequences for the building fabric 206
4.5 Moisture tolerance 208
4.5.1 In general 208
4.5.2 Construction moisture 208
4.5.2.1 Definition 208
4.5.2.2 Performance requirements 208
4.5.2.3 Consequences for the building fabric 209
4.5.3 Rain 210
4.5.3.1 The problem 210
4.5.3.2 Performance requirements 212
4.5.3.3 Modelling 213
4.5.3.4 Consequences for the building envelope 215
4.5.4 Rising damp 217
4.5.4.1 Definition 217
4.5.4.2 Performance requirements 217
4.5.4.3 Modelling 218
4.5.4.4 Avoiding or curing rising damp 221
4.5.5 Pressure heads 222
4.5.5.1 Definition 222
4.5.5.2 Performance requirements 223
4.5.5.3 Modelling 223
4.5.5.4 Protecting the building fabric 223
4.5.6 Accidental leaks 224
4.5.7 Hygroscopic moisture 224
4.5.7.1 Definition 224
4.5.7.2 Performance requirements 226
4.5.7.3 Modelling 226
4.5.7.4 Consequences for the building fabric 226
4.5.8 Surface condensation 226
4.5.8.1 Definition 226
4.5.8.2 Performance requirements 226
4.5.8.3 Modelling 227
4.5.8.4 Consequences for the envelope 228
4.5.9 Interstitial condensation 228
4.5.9.1 Definition 228
4.5.9.2 Modelling 229
4.5.9.3 Performance requirements 232
4.5.9.4 Consequences for the building envelope 233
4.5.9.5 Remark 234
4.5.10 All moisture sources combined 234
4.5.10.1 Modelling 234
4.5.10.2 Performance requirements 234
4.5.10.3 Why models still have limitations 236
4.5.10.4 Three examples where full models were hardly of any help 240
4.6 Thermal bridges 244
4.6.1 Definition 244
4.6.2 Performance requirements 245
4.6.3 Consequences for the envelope 245
4.7 Contact coefficients 245
4.8 Hygrothermal stress and strain 246
4.9 Transparent parts: solar transmittance 247
4.9.1 Definition 247
4.9.2 Performance requirements 247
4.9.3 Consequences for the envelope 248
Further reading 248
5 Timber-framed outer wall as an exemplary case 253
5.1 In general 253
5.2 Assembly 253
5.3 Heat, air, moisture performances 253
5.3.1 Airtightness 253
5.3.2 Thermal transmittance. 255
5.3.3 Transient response 257
5.3.4 Moisture tolerance 257
5.3.4.1 Construction moisture 257
5.3.4.2 Rain control 257
5.3.4.3 Rising damp 258
5.3.4.4 Hygroscopic moisture and surface condensation 258
5.3.4.5 Interstitial condensation 258
5.3.4.6 More advanced modelling 264
5.3.4.7 Thermal bridging 265
6 Heat-air-moisture material properties 266
6.1 Introduction 266
6.2 Dry air and water 267
6.3 Materials, thermal properties 268
6.3.1 Definitions 268
6.3.2 Design values 268
6.3.2.1 Non-certified materials (ISO 10456) 268
6.3.2.2 Design values (NBN B62-002 (2001)) 272
6.3.3 Measured data 281
6.3.3.1 Building materials 281
6.3.3.2 Insulation materials 287
6.4 Materials, air-related properties 290
6.4.1 Design values 290
6.4.1.1 Measured values 291
6.5 Materials, moisture properties 304
6.5.1 Design values for the vapour resistance factor (ISO 10456) 304
6.5.1.1 Building and finishing materials 304
6.5.1.2 Insulation materials 309
6.5.2 Measured values 309
6.5.2.1 Building materials 310
6.5.2.2 Insulation materials 323
6.5.2.3 Finishes 324
6.5.2.4 Miscellaneous 326
6.5.2.5 Vapour retarders 327
6.6 Surfaces, radiant properties 328
Further reading 329
Appendix A: Solar radiation for Uccle, Belgium, 50° 51¿ north, 4° 21¿ east 331
0
Introduction
0.1 Subject of the Book
This is the second volume in a series of four books:
- - Building Physics: Heat, Air and Moisture
- - Applied Building Physics: Boundary Conditions, Building Performance and Material Properties
- - Performance Based Building Design: from below grade construction to cavity walls
- - Performance Based Building Design: from timber-framed construction to partition walls.
Subjects discussed in this volume are: outdoor and indoor ambient conditions, performance concept, performance at the urban, building and building envelope level and the heat-air-moisture material properties. The book figures as a hinge between 'Building Physics: Heat, Air and Moisture' and the two volumes on 'Performance Based Building Design'. Although it does not deal with acoustics and lighting in detail, they form an integral part of the performance arrays and are mentioned as and when necessary.
The outdoor and indoor ambient conditions and related design approaches are highlighted in Chapter 1. Chapter 2 advances the performance concept with its hierarchical structure, going from the urban environment across the building and building assemblies down to the layer and material level. In Chapter 3, the main heat, air and moisture linked performances at the building level are discussed, while Chapter 4 analyses related metrics of importance for a well-performing building envelope and fabric. Chapter 5 deals with timber-framed walls as an exemplary case, and Chapter 6 lists the main heat, air and moisture material property values needed to predict the response of building assemblies.
A performance approach helps designers, consulting engineers and contractors to better ensure building quality. Of course, physical integrity is not the only factor adding value to buildings. Functionality, spatial quality and aesthetics - aspects belonging to the architect's responsibility - are of equal importance, though they should not cause us to neglect the importance of an overall outstanding building performance.
0.2 Building Physics Vs. Applied Building Physics
Readers who would like to know more about the engineering field 'building physics', its importance and history, should consult the first volume, 'Building Physics: Heat, Air and Moisture'. It might seem that adding the term 'applied' to this second volume is unnecessary - building physics is, by definition, applied. Rather, the word stresses the focus of this book: entirely directed towards its use in building design and construction.
0.3 Units and Symbols
The book uses the SI system (internationally mandated since 1977). Its base units are the metre (m), the kilogram (kg), the second (s), the kelvin (K), the ampere (A) and the candela. Derived units of importance when studying applied building physics are:
Force: newton (N); 1 N = 1 kg·m·s-2 Pressure: pascal (Pa); 1 Pa = 1 N/m2 = 1 kg·m-1·s-2 Energy: joule (J); 1 J = 1 N·m = 1 kg·m2·s-2 Power: watt (W); 1 W = 1 J·s-1 = 1 kg·m2·s-3For symbols, the ISO-standards (International Standardization Organization) are followed. If a quantity is not included, the CIB-W40 recommendations (International Council for Building Research, Studies and Documentation, Working Group 'Heat and Moisture Transfer in Buildings') and the list edited by Annex 24 of the IEA EBC (International Energy Agency, Executive Committee on Energy in Buildings and Communities) apply.
Table 0.1 List with symbols and quantities
Symbol Meaning SI units a Acceleration m/s2 a Thermal diffusivity m2/s b Thermal effusivity W/(m2·K·s0.5) c Specific heat capacity J/(kg·K) c Concentration kg/m3, g/m3 e Emissivity - f Specific free energy J/kg Temperature ratio - g Specific free enthalpy J/kg g Acceleration by gravity m/s2 g Mass flux kg/(m2·s) h Height m h Specific enthalpy J/kg h Surface film coefficient for heat transfer W/(m2·K) k Mass related permeability (mass could be moisture, air, salt.) s l Length m l Specific enthalpy of evaporation or melting J/kg m Mass kg n Ventilation rate s-1, h-1 p Partial pressure Pa q Heat flux W/m2 r Radius m s Specific entropy J/(kg·K) t Time s u Specific latent energy J/kg v Velocity m/s w Moisture content kg/m3 x,y,z Cartesian coordinates m A Water sorption coefficient kg/(m2·s0.5) A Area m2 B Water penetration coefficient m/s0.5 D Diffusion coefficient m2/s D Moisture diffusivity m2/s E Irradiation W/m2 F Free energy J G Free enthalpy J G Mass flow (mass = vapour, water, air, salt) kg/s H Enthalpy J I Radiation intensity J/rad K Thermal moisture diffusion coefficient kg/(m·s·K) K Mass permeance s/m K Force N L Luminosity W/m2 M Emittance W/m2 P Power W P Thermal permeance W/(m2·K) P Total pressure Pa Q Heat J R Thermal resistance m2·K/W R Gas constant J/(kg·K) S Entropy J/K S Saturation degree - T Absolute temperature K T Period (of a vibration or a wave) s, days,. U Latent energy J U Thermal transmittance W/(m2·K) V Volume m3 W Air resistance m/s X Moisture ratio kg/kg Z Diffusion resistance m/s a Thermal expansion coefficient K-1 a Absorptivity - ß Surface film coefficient for...