Sustainable Built Environment

1. Sustainable Built Environment Chapter 2: The Climate

2. 2.2The Urban Climate 2.4. Outdoor Air Pollution 2.1 Ralations Between Climate and Building 2.3. The Wind Environment of Building Contents 2 A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

3. Climate Summary Ralations Between Climatic Zones and Building Design Climate Changes and Its Effectson Climate Design Ralations Between Climate and Building 2.1 Ralations Between Climate and Building A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

4. Climate Summary • Air temperature • Humidity • Solar radiation Meteorological elements • Multi Year Datasets • Typycal Year Data • Representative Days Data Meteorological data A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

5. Introduction to Climate • The variables of interest for weather forecasting (and for building design) are: • Air temperature (dry bulb and wet bulb) • Atmospheric pressure and wind (velocity and direction) • Precipitation (rainfall, snow cover etc) • Solar radiation (direct and diffuse) • Cloud Cover A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

6. Ralation Between Climate and Building R Northwest Southwest A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

7. Climate Building Create a safe place to adapt to climate Get rich architectural form according to the variety of climate Guard Use Ralation Between Climate and Building A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

8. Division of climatic zones Ocean current Latitude Distance to sea Terrain Climatic zones 18 kinds: Plateau climate、Tropical rain forest climate etc. A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

9. Characteristics of climate zones in China • Monsoon climate is obvious • Continental climate is strong • Climate types is various A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

10. Climate zones in China Similarworkhas been carried out recently for China. Fiveclimatic zones are proposed as illustrated here A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

11. Climatic zones and building design The active and passive method of an architectural designing is related to local climate features closely. So the bioclimatic chart make a relation between building design and local clamatic zones. In addition to extreme climate zones,passive method can saving energe and make comfortable conditions A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

12. Climatic zones in relation to building design Bioclimatic chart proposed by Olgyay in the 1960’s A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

13. Climatic zones in relation to building design The original bioclimatic chart proposed by Givoni A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

14. Climatic zones in relation to building design Bioclimatic chart adapted from Givoni can be used to assess the suitability of ventilation and activated thermal mass for summer climatic conditions in the UK. A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

15. Climatic zones in relation to building design Bioclimatic chart for Beijing (cold region). A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

16. Climatic zones in relation to building design For more detail visualisation and assessment for a region, the original bioclimatic chart can be used and the specific climatic envelope for a region can beplotted -- an example for Hong Kong is shown here A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

17. Climate change and its effect on climate design • Climate is changing • The impact on buildings and services must be addressed • Development of future climate scenarios depends on making assumptions • In the UK, there exist publications by CIBSE on this subject • There are specific impacts on climate in the cities where most buildings are located A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

18. 2.2 : The Urban climate 1.urban areas 2.Temperature distribution 3.Urban Heat Island A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

19. Most buildings are urban building design in urban cites can be very different than rural sites mainly due to: High temperatures due to urban heat island Changes in solar radiation absorption Reduced wind speeds Increased external pollutants Increased noise levels Map of stable night lights in Europe. A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

20. questions urban heat island: Why does the temperature of a city differ from its surrounding area? urban wind field: Why do wind patterns and wind strength in a city differ from its surrounding area? urban solar radiation: What factors affect the solar radiation in an urban area? atmospheric pollution: What is the effect of air pollution? urban noise: What is the effect of external noise levels? A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

21. Temperature distribution and Urban Heat Island A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

22. What is different in urban areas? 1.Reduced solar radiation Urban areas have less sunshine than their surroundings. In industrial cities, the loss in sunshine duration may be between 10% and 20%. The energy reduction is more important at low solar elevations and less important at high solar elevations. A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

23. What is different in urban areas? 2.Albedo -Radiation is not only emitted, absorbed, and transferred, but also reflected. -The albedo of a surface is its reflectivity that is reflected to that which strikes the surface. -The sum of the albedos of the many surfaces of the earth are important in determining the earth's energy balance, which is also a factor contributing to theurban heat island. A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

24. What is different in urban areas? 3.Increased pollution -Airborne pollutants also affect energy balance. -Pollutants react with other natural and anthropogenic chemicals，releasing or absorbing heat energy. -Some pollutants also play a role in the greenhouse effect. -Chemistry plays an important role in energy balance in the atmosphere. A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

25. -the changes in air temperature due to urbanisation. -urban climate is warmer and less windy than in rural areas. A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

26. Temperature difference between urban and rural in a day The difference between urban and rural temperatures is highly dependent on the time of day. Urban environments is warmer before sunrise than rural ones, because they have cooled down overnight at a slower rate (primarily because clusters of buildings increase the heat capacity of the area and reduce its radiative cooling efficiency). As the sun rises, solar energy evaporates dew in rural areas (energy is absorbed as latent heat, with no temperature rise), but starts heating up urban fabric immediately. When the dew has evaporated, the rural surfaces start to warm up more rapidly than the urban ones, because of their lower heat capacity. before sunset, the rural surfaces rapidly cool, the rate reducing as dew is formed and latent heat released. The city cools more slowly and the urban to rural temperature difference starts to rise. A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

27. UHI intensity variation A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

28. Bad influence In the summertime, the urban heat island has an impact on air-conditioned and passively cooled buildings: increased external temperature results in an increased energy demand for cooling. night-time cooling potential is reduced hot periods lead to a dramatic rise in the demand for air conditioning, increasing the peak electricity demand: air conditioning systems are less efficient when operating under large temperature differences. the profile of temperature and wind in an urban environment is modified and this affects the efficacy of passive cooling designs. A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

29. Prediction models for urban temperatures Climatology models: These are detailed but are complex and require specific expertise for accurate predictions. Empirical models based on heat balance principles :been studied by building physicists Computational Fluid Dynamics (CFD) models: predict air flow within the urban environment but also temperature fields. （although reasonably accurate in many cases, require a large amount of input data with the corresponding uncertainties） Analysis of variance and regression: examine the effect of weather conditions on the UHII Artificial Neural Networks (ANNs):The UHII as affected by synoptic climatic parameters A Multidisciplinary Approach to Curriculum Development in Sustainable Built Environment

30. 2.3 The wind environment of Building 2.3.1 characteristics of Building wind environment 2.3.2 The evaluationofBuilding wind environment 2.3.3 The consideration of wind environmental factors In Regional planning and architectural design

31. If the wind environment of Residential outdoor is bad, the natural ventilation can be hindered because of poor ventilation in summer and the energy consumption of air conditioning is increased; The penetration of palisade structure is increased because of the large wind speed and the energy consumption of heating. Then,the good quality of wind environment can reduce the energy consumption and improve the residential environment;It can also provide the architectural design or layout scheme of urban area with the data of wind environment .

32. 2.3.1 The characteristicsofBuilding wind environment the eddy current of Windward side :when wind come across the high buildings,one part will form eddy in front of wall. the wake stream of buliding: when wind come across the high buildings,one part will form air swirl on the back of wall. the draught: the air stream flow quickly can form in the channel of building because of preassure difference.

35. strong winds of edges: when wind come across the sides of the wall,the air stream can generate vortex separation. effect of growth of the velocity:the velocity of wind will become faster and form phenomenon of high speed.

37. the shadowing effect: when the buildings of approximate height and the size are built adjacently, the latter building will have an shadowing effect on the oncoming air stream. street canyon effect: the buildings which are built along street and adjacently in metropolitan are of flat facades,so when windblowperpendicular to the street , the swirl air will generate.

41. 2.3.1 The evaluationofBuilding wind environment For the evaluationofbuilding wind environment,there is no Unified standard about the comfortable and risk velocity of the building surroundings. Now there are mainly several ways: (1) Relative comfort evaluation method: the highest frequency of acceptable defined by different levels of discomfort is Comfort assessment criteria. (2) the evaluation method on wind speed ratio:the velocity ratio reflects the degree of the change because of the bulidinds.The perception is defined: =

42. the velocity ratio —wind speed at i point location of pedestrian-level the oncoming undisturbed speed at pedestrian-level We combine wind speed ratio of the field and wind rose diagram to get the actual wind speed .

43. 2.3.2 The consideration of wind environmental factors In Regional planning and architectural design （1）the influence of wind environment fordistrict planning If the density of buildings is too large,the wind will be hindered and  the situations of ventilation  will be poor;on the contrary,the polluted air in the street and district can be easily dispersed and the apparent temperature of walkers can decrease. Now we always use wind tunnel test to simulate the wind environment. （2）The prevention and improvement of wind environment

44. We should survey location of buildings to ensure a clear understanding to the wind environment. (1) adjusting the orientation or appearancestructure of the structure we can use the skirt building or arcadeto change the appearance. (2) setting the windbreak facilities we can use wind barrier and vegetation Cover to Weaken the influence of the strong wind.

45. Outline I. Outdoor air pollution A. Source B. Harm C. Solution II. Weather data A. Heating and cooling degree days B. Sources

46. 2.4 Urban outdoor pollution Harm Sources Burning of fuel Residential coal burning Traffic transportation Factories Power plants

47. Harm Source Dust Construction sites Mines Deserts

48. Harm Type1 + Haze(雾霾)

49. Harm Type2 SO2 Sulfur dioxide *SO42- Sulfur dioxide smog SO2 compounds

50. Harm Type3 NOx Nitrogen oxides + Photochemical smog