9 th UK CARE Annual General Meeting Dynamic Analysis for Daylight Availability in High-Density Urban Area 高密度城市区域动态采光分析 杜 江 涛 Jiangtao Du (PhD student) Architecture School University of Sheffield

9 th UK CARE Annual General Meeting ABSTRACT This study describes a dynamic analysis method to investigate daylight availability in high-density urban area. In contrast to traditional static concept based on Daylight Factor, this method introduces Daylight Coefficient and Perez sky luminance function, which can be used to dynamically analysize the annual daylight level profile. Daylight Coefficient on the outside surfaces of buildings has been calculated by DaySim, a package using Radiance algorithm. Also, Sky Luminance Distribution comes from annual solar gains through Perez’s sky model function. Accordingly, integrating Daylight Coefficient and sky luminance distribution would get illuminace values across the outside surfaces. The annual illuminance profile of there surfaces is a significant indicator for daylight levels in buildings. Three typical built layouts in current high-density Chinese city have been modelled and simulated. The solar radiation data in the simulation are derived from the weather file (2005) of Beijing and Shanghai, which represent different weather zones (II and III) in China and both have plenty of high-density lots. The proposed methodology can help urban and building designers evaluate the possibilities of using natural lighting in high-density area from the early conceptual design stages.

9 th UK CARE Annual General Meeting INTRODUCTION High-density Urban Area important environmental issue: daylit spaces; building type: residential buildings; commercial buildings. Natural Light Availability and Performance component: skylight and sunlight. benefit: reducing artificial light; saving energy; improve indoor qualities (psychology). Daylight and Sunlight code in China [1,2] GB/T Standard for daylighting design of buildings 建筑采光设计标准 GB (2002) Code of urban residential areas planning & design 城市居住区规划设计规范

9 th UK CARE Annual General Meeting GB/T Standard for daylighting design of buildings 建筑采光设计标准 [1] GB (2002) Code of urban residential areas planning & design 城市居住区规划设计规范 [2] 光气候分区：五类区域 采光系数 (DF) ：居住建筑 1% 办公建筑 2% 建筑气候分区：七个区域 日照标准：居住建筑 大寒日 或者 冬至日 日照时数 Static method for daylighting controlling in buildings, simple; Easily adopted, but not corresponding to the real climate conditions and urban layout; Low practical feasibility and lacking flexibility. Climate-based Dynamic model or method [3]

9 th UK CARE Annual General Meeting METHODOLOGY Climate-based Dynamic model ---- Daylight Coefficient and Perez sky model Daylight Coefficient 145 patches Peter Tregeza [4] [5] [6]

9 th UK CARE Annual General Meeting Perez sky model [7, 8] R. Perez, R. Seals, J. Michalsky; All-weather model for sky luminance distribution — preliminary configuration and validation Solar Energy –245. R. Perez, P. Ineichen, R. Seals, J. Michalsky, R. Stewart; Modeling daylight availability and irradiance components from direct and global irradiance Solar Energy –289. Three ways to produce the luminance distribution of sky: Direct radiation, diffuse radiation Global illminance, diffuse illuminance Coefficients setting: a,b,c,d,e Sky luminanceDCE [5]

9 th UK CARE Annual General Meeting Climate-based Dynamic method for urban daylight availability analysis Typical positions on the Vertical surface of building Daylight Coefficient of reference positions Weather data of test reference year (TRY) Annual illuminance profile (5 minutes, 10 minutes, 0.5 hour, 1 hour) [9]

9 th UK CARE Annual General Meeting Case analysis for daylight availability analysis in high-density urban area 1. Linear layout 2. Court layout 3. Dot layout Higher position Middle position Lower position Beijing: II 寒冷地区 III 光气候区 Shanghai: III 夏热冬冷地区 IV 光气候区 north [1, 2]

9 th UK CARE Annual General Meeting RESULTS Day: 20/01 ( 大寒） 20/03 ( 春分） 21/06 ( 夏至） 23/09 ( 秋分） 22/12 ( 冬至） Step: 1 hour Beijing 1-20

9 th UK CARE Annual General Meeting 3-20 Beijing

9 th UK CARE Annual General Meeting Shanghai 1-20

9 th UK CARE Annual General Meeting 3-20 Shanghai

9 th UK CARE Annual General Meeting Beijing 1-20

9 th UK CARE Annual General Meeting Beijing

9 th UK CARE Annual General Meeting Shanghai 1-20

9 th UK CARE Annual General Meeting Shanghai

9 th UK CARE Annual General Meeting Beijing 1-20

9 th UK CARE Annual General Meeting Beijing

9 th UK CARE Annual General Meeting Shanghai 1-20

9 th UK CARE Annual General Meeting Shanghai

9 th UK CARE Annual General Meeting CONCLUSIONS A real dynamic method for daylight availability investigation; based on the weather data (radiation); Illuminace output, easily to understand and compile; Based on DC and Radiance algorithm (DaySim), suitable for complicated environment; More knowledge needed when using the tool; long running time; thousands of data.

9 th UK CARE Annual General Meeting REFERENCES 1. GB/T Standard for daylighting design of buildings 建筑采光设计标准 2. GB (2002) Code of urban residential areas planning & design 城市居住区规划设计规范 3. BS :2008 Lighting for buildings – Part 2: Code of practice for daylighting P R. Tregenza, M I. Waters; Daylight Coefficients.Lighting research and technology – J.Mardaljevic; Daylight Simulation: Validation, Sky Models and Daylight Coefficients. PhD Thesis 2000 De Moutfort University. 6. C. Reinhart, S. Herkel; The simulation of annual daylight illuminace distributions – a state-of-art comparison of six Radiance- based method. Energy and Buildings – R. Perez, R. Seals, J. Michalsky; All-weather model for sky luminance distribution — preliminary configuration and validation Solar Energy – R. Perez, P. Ineichen, R. Seals, J. Michalsky, R. Stewart; Modeling daylight availability and irradiance components from direct and global irradiance. Solar Energy – C. Reinhart, O. Walkenhorst; Validation of dynamic Raidance-based daylight simulations for a test office with external blinds. Energy and Buildings –697.