This paper explores the method of assessing regional spatial ventilation performance for the design of residential building arrangements at an operational level. Three ventilation efficiency (VE) indices, Net Escape Velocity (NEV), Visitation Frequency (VF) and spatial-mean Velocity Magnitude (VM), are adopted to quantify the influence of design variation on VE within different regional spaces. Computational Fluid Dynamics (CFD) method is applied to calculate VE indices mentioned above. Several residential building arrangement cases are set to discuss the effect of different building length, lateral spacing and layouts on four typical space patterns under wind directions oblique or perpendicular to the main (long) building facade. The simulation results prove that NEV, VF and VM are useful VE indices, which can reflect different features of flow pattern in studied regional domains. Preliminary parametric studies indicate that wind direction might be the most important factor for improving spatial ventilation. When the angle between main building facade and wind direction is more than 30°, ventilation of different exterior spaces could improve evidently. When wind direction is perpendicular to main building façade, decreasing building length can increase NEV of the middle space by 50%, while decreasing lateral spacing would decrease NEV of the intersection space by 35%.

Using computational fluid dynamic (CFD) simulations, the correlation between residential building arrangement designs and ventilation efficiency of various outdoor spaces is explored. Three indices—purging flow rate (PFR), visitation frequency (VF) and air residence time (T_p)—are adopted to quantify the ventilation efficiency of regional outdoor spaces. Using these indices, changes in residential building lateral spacing, building length, and stagger size were investigated under the effects of different surrounding building arrays for different wind directions. The simulation results indicated that wind direction is the most important factor for improving the residential wind environment, regardless of the patterns of the surrounding building arrays. When the angle between the wind direction and the building’s main façade orientation is more than 30°, the ventilation of different outdoor spaces improves. Staggered surrounding building arrays lower the spatial ventilation of the studied areas. However, this staggering does not affect the variation trend of spatial ventilation influenced by building arrangement design changes.

The façade opening design has a comprehensive influence on the building performance in daylighting, solar heat gain and natural ventilation. This study is aimed to investigate the influence on integrated energy consumption on an operational level, conducted through computer simulation techniques based on EnergyPlus in combination with Fluent. To facilitate the model establishment, an automatic generation program has been developed by MATLAB. With this program, three aspects of façade configurations under different sheltering conditions have been modelled. The simulation results show that opening area, prior to opening positions, is a greater foremost influential factor on total energy consumption under different sheltering conditions. In the meanwhile, the east and west sheltering walls exert a considerable influence on daylighting and natural ventilation. Compared with unsheltered façades, the cooling energy consumption in transition seasons could drop by 4% in the west-side sheltering condition, while increasing by 12% in the east-side sheltering condition.

Yihui Yang, Wei You, Yunlong Peng, Wowo Ding*, School of Architecture and Urban Planning, Nanjing University, No.22 Hankou Rd, Jiangsu 210093, P.R.China. E-mail:yi_hui_yang@outlook.com, youwei@nju.edu.cn, 249626020@qq.com, dww@nju.edu.cn,Phone number:15850561165, 13852293251, +86 25 83593020, Keyword: Residential plot, Apartment pattern, performance evaluation, wind environment Conference topics and scale: Tools of analysis in urban morphology Residential morphological patterns are reflection of people's living habits and tradition, local climate and building regulations, so that one of those factors could be studied through in order to understand residential morphological patterns. Based upon our previous study, we do know that in China living habits and local climate mainly influence the shape of residential buildings and apartment patterns, but we do not know whether the pattern of residential plots determined by FAR and sunshine hours are suitable for wind environment related to residential environmental quality. Therefore, it is very significant to evaluate wind environment within residential plots based on the apartment pattern controlled by various building codes. Our study focuses on the pattern of Slab apartments in Nanjing, which are mainly used in China, and selects 40 residential slices with different plot shapes, plot FAR, building heights and sizes. Based upon MATLAB, we have got all geometrical data between buildings among these slices to identify the spatial pattern character of each residential plot. Through evaluating wind environment of these slices by simulation we can obtain wind speed, pressure and age of air and choose the pattern of age of air as the main evaluation factor of wind performance. Correlation analysis will be made between the apartment patterns and pattern of age of air, by doing so, each typical space between buildings will be evaluated. Our study will reveal the relevance of apartment pattern and wind environment, which can be used to support and improve design in the future. References（95 words） Oke. T. R (1988) ‘Street Design and Urban Canopy Layer Climate’, Energy and Buildings11, 103-113. Wowo Ding, Youpei Hu, Pingping Dou (2012) ‘Study on Interrelationship between Urban Pattern and Urban Microclimate’, Architectural Journal 527, 16-21. Edward Ng, Chao Yuan, Liang Chen, Chao Ren, Jimmy C.H. Fung (2011) ‘Improving the wind environment in high-density cities by understanding urban morphology and surface roughness: A study in Hong Kong’, Landscape and Urban Planning101, 59-74. Youpei Hu (2014) ‘A Performance-Oriented Study on the Morphological Optimization in a High Density Area Concerning Urban Heat Island Effect’, Architectural Journal 557, 23-29. *corresponding author