寒地办公建筑夹层空间自然采光性能参数化模拟研究

Parametric Daylight Performance Simulation Research of Mezzanine Space in Office Buildings in Severe Cold Regions

自然采光对提升建筑室内光舒适、降低建筑能耗有重要作用。设有夹层的开放办公空间灵活性强、面积利用率高,空间自然采光状况较为复杂。为研究夹层空间形态对室内自然采光性能的影响,本文以全年有效天然采光照度(UDI_(100-2000))和全天然采光百分比(DA450)为自然采光性能评价指标,基于grasshopper参数化平台,应用Radiance和Daysim展开自然采光性能参数化模拟实验,分析夹层布局位置、夹层面积占比、夹层退窗比例等设计参量对室内自然采光性能的影响,为自然采光性能导向下的开放办公建筑夹层空间设计与改造提供理论和技术支持。实验结果表明:不同的夹层位置对夹层上下空间自然采光性能影响差异较大,南侧夹层布置方式更有利于提高室内UDI_(100-2000)水平,东西侧夹层布置方式下的DA450相对更高;夹层面积的提高会对室内自然采光性能产生不利影响,而夹层面积占比为50%时,夹层的UDI_(100-2000)水平最高;适当提高夹层退离窗的距离有利于改善夹层空间的UDI_(100-2000)水平,夹层退窗比例达到10%~20%时为相对最优。

Daylight plays a significant role in improving the indoor environment and reducing energy consumption.Open office building with mezzanine space has the characteristics of high flexibility and high space utilization,but the mezzanine will probably add more complexity to the indoor daylight performance.In this paper,in order to analyze some factors that affect the daylight performance of open office buildings with mezzanine and provides some suggestions for prospective in daylight performance-oriented design of mezzanine space in open office buildings.In this paper,firstly,Useful Daylight Illuminance(UDI_(100-2000))and Daylight Autonomy(DA450)are adopted as the dynamic daylight metrics,these two metrics take oration,use time and climate conditions into consideration,they are more suitable for evaluating annual daylight performance compared to daylight factor(DF).A 3D model of an open office room with a ratio of glazing to the floor area of 1/5 was established in this research.Based on a computer way,a Parametric Daylight Performance Simulation model was built based on the grasshopper platform,contains geometric parameter module of the office room,mezzanine space design module,Material optical parameter module,simulation and visualization module and data output module.The analysis plane was 0.75 meters above the floor and analysis grid was set to be 1.0*1.0 meter,generic materials with typical surface reflectance were assumed in this research according to china’s standard for daylighting design of buildings.Some simulations were carried on using Radiance and Daysim to assess daylight performance in office buildings.This study utilized the fast and accurate simulation parameters to calculate daylight metrics.Aiming to find the relationship between the daylight performance and mezzanine space,a series of versions of mezzanine space was set with changing the site of the mezzanine,the area ratio of the mezzanine to the room and ratio of the backward distance of the mezzanine to the depth.A total of 42 simulations were carried out for further analysis.According to the simulation results,in the aspect of the site of the mezzanine,indoor daylight performance turns to be different for the room with different site of the mezzanine.For space under the mezzanine,the DA450 value peaks with northern site of mezzanine,which is 20%higher than that with southern mezzanine.The DA450 value with western mezzanine is similar to that with eastern mezzanine.However,the DA450 on the mezzanine turns to be opposite with the daylight conditions under the mezzanine.The entire indoor DA450 does not present a significant difference between different sites of mezzanine.The UDI_(100-2000) conditions turn to be consistent in the room,the room with southern mezzanine presents more optimal UDI_(100-2000) than others.The UDI_(100-2000) value of the room with western mezzanine turns to be similar to that of eastern one as well.The indoor entire daylight performance reduces with the increase of the area of the mezzanine.For space under the mezzanine,the DA450 value and UDI_(100-2000) value decrease with the increase of the area of the mezzanine.for space on the mezzanine,the daylight performance conditions turn to be variable.The DA450 value of southern mezzanine increases with the increase of the area of the mezzanine.However,the UDI_(100-2000) value of southern mezzanine presents a rise-fall-rise tendency with a peak value of 65%at the area ratio of the mezzanine to the room of 50%.The UDI_(100-2000) value of northern mezzanine presents a rising tendency and changes into stable after the area ratio of the mezzanine to the room reach 60%.It seems that altering the area ratio of the mezzanine has little effect on the daylight performance of room with western and eastern mezzanine,owing to no changes in the depth direction.For southern sited office room,with the increase of the ratio of the backward distance to the depth,the DA450 value of the space on and under the mezzanine enhances and decreases respectively.The entire indoor DA450 represents little changes.The UDI_(100-2000) value of the space under the mezzanine decreases and changes into stable,however,the UDI_(100-2000) value of the space on the mezzanine turns to be a rise-fall trend,peaking at the ratio of the backward distance to the depth of 20%for the room with not more than 50%area ratio of the mezzanine to the room and at that of 10%for the room with beyond 50%area ratio of the mezzanine to the room.