不同使用时段对中小学教育建筑室内采光及窗墙比模式的影响

中小学教室使用强调自然采光的效果,传统的建筑设计缺乏针对小学与中学使用时段差异对自然采光需求不同的研究。今以长江三角洲地区中小学教学楼为研究对象,以中小学放学时段的差异为分析条件,建立标准教室尺寸模型,用DIALUX模拟三个特征日期下不同放学时间段教室内工作面照度,分析不同窗墙形态下的工作面照度值。分析结果表明:距窗边2.3 m范围内不适宜摆放课桌椅;从照度标准、人眼舒适率、纵向突变值、采光均匀度分别考虑了中小学建筑合适的窗墙比:小学建筑适合的窗墙比为1∶3.5,窗高为1.8 m左右;中学建筑适合窗墙比为1∶3.5、1∶4,窗高为1.8～2 m。     

西安市高校教室光环境优化设计研究

在高校教室的设计中,舒适健康的自然光环境不仅使学生有良好的心里感受,更能提高建筑的节能效率。本研究以西安市某高校的典型教室作为研究对象,通过节能分析软件Ecotect及采光模拟软件Radiance,对其冬、夏季的采光遮阳情况做出模拟分析。在科学分析模拟结果的基础上,对不同遮阳方式、窗墙比大小和采光口比例等影响因素进行量化分析,提出提高高校教室光环境质量的建议。     

单侧采光设计对办公建筑室内自然采光系数影响模拟分析

通过Ecotect软件建立模型,研究分析办公建筑侧窗采光的影响因素(窗墙比、玻璃可见光透射率、窗台高度、进深),建立各影响因素与采光系数的定量关系。结果表明,上述因素对采光系数影响显著,且以进深的影响最明显。窗墙比和玻璃可见光透射率与采光系数成线性关系,窗台高度与其成二次项关系,进深与其成指数关系。增加窗墙比和玻璃可见光透射率,减小房间进深,控制窗台高度在中间略偏下的位置,有助于提高建筑采光系数,改善室内光环境。     

基于建筑水平外遮阳采光口的优化设计研究

基于固定水平外遮阳,通过分析、整合建筑遮阳和采光的影响因素,提出了耦合遮阳和采光的设计方法:在不改变建筑的外遮阳系数的前提下,调整采光口的形状以优化室内自然采光,并利用ECOTECT软件进一步分析了房间进深和水平遮阳出挑长度不同时,采光口形状对室内平均采光系数的影响,结果表明在遮阳板出挑长度、采光口面积、窗台高相同的情况下,采用横窗时室内的平均采光系数较高,并将该结论应用于教学建筑方案设计中,优化了室内的自然采光使之满足采光标准的要求。     

基于BIM技术的绿色建筑性能分析与优化方法研究

针对绿色建筑性能分析过程中的可视化需求和方案比选难度大、效率低的难题,以浙江省东阳市某社区安置点项目为研究对象,借助BIM技术模型对建筑场地环境的风场环境和光照环境进行数值仿真分析。结果表明,小区周边区域风速基本在1.5m/s以内,小区内的平均风速约为1m/s,符合行人舒适性要求;SY3商业楼首层和标准差采光效果均较好,达到了Ⅲ级采光要求,采光系数大于2.2%,平均采光系数为3.58%;随着窗墙比的增加,建筑采暖及热水的能耗增加幅度为11.72%,空调制冷能耗增加幅度为8.34%,通风系统能耗增加幅度为3.10%,单位面积平均能耗增加幅度为5.86%;随着窗墙比的增加,通风系统能耗不断降低,降低幅度为15.98%;随着窗墙比的增加,办公设备的能耗不变,为712.5 kWh;综合考虑,可以确定窗墙比为0.30为最优方案。     

重庆农村住宅建筑典型外窗采光性能分析

近年来农村住宅建设进入大建设时期,农村住宅在层数、结构以及居民使用时间上与城市住宅有很大不同,现有研究很少针对农村住宅建筑,并且大多关注优化外窗节能设计而忽视改善室内的光环境,尤其是重庆地区等光气候条件很差的地方。构成外窗主要因子有窗墙比、玻璃类型、外遮阳板等,外窗因子影响采光和空调能耗的程度不同,并且采光和空调能耗之间本身就是对立的。采用室内平均采光系数作为评价参数,针对重庆农村地区,采用DesignBuilder软件建立典型农村住宅建筑模型,利用SPSS正交试验方法,得到窗墙比、玻璃类型及遮阳板对自然采光影响效应程度大小顺序：窗墙比＞玻璃类型＞外遮阳板,并通过采光达标情况判定得到了不同玻璃类型和遮阳情况的最小窗墙比。     

基于能耗与采光分析的夏热冬暖地区办公建筑窗墙比优化取值研究

通过建筑能耗模拟分析得出典型办公建筑中窗墙面积比对建筑能耗的影响,再通过建筑采光模拟分析得出窗墙面积比对建筑采光的一般规律。在提高采光效果和采光质量的同时,随着建筑窗墙比的提升,建筑围护结构能耗也会有所增加。因此在综合考虑建筑能耗和采光这两个因素的条件下,得出一个适宜的窗墙比取值区间。并通过定义光耗比来表征单位能耗提高对采光效果的影响,以提出办公建筑最优的窗墙面积比取值,使建筑能通过牺牲最小的能耗值,得到性价比最为优化的采光效果和质量。选取夏热冬暖典型城市的建筑能耗及室内平均采光系数进行模拟综合分析,并得出结论,为建筑节能设计提供参考。     

办公建筑的天然采光实验研究

对办公建筑的天然采光进行了实验研究。首先,从理论和模拟两个角度分析了模型和原型的照度分布相似性,并建立了办公室实验模型;其次,由于天空状态的多变性,提出用天然采光系数替代照度进行实验验证;最后,通过实验测试,分别验证了窗墙比、窗台高和透光率对室内照度分布的影响,分析了产生各种误差的原因,结果表明误差均在可接受范围内。     

严寒地区公共建筑光热环境贡献度研究

结合简单教学模型,利用Ecotect软件,针对建筑物理性能中的光、热性能进行仿真模拟分析。对于光环境分析,得出在进深较大的教学建筑中采取矩形天窗较有优势;通过设置不同窗墙比得到了与采光系数及达标面积之间关系。在窗墙比增加一定幅度基础上,通过达标面积率变化情况得到建筑采光得分变化。针对热环境,设置不同围护结构改造方案进行模拟,在以节能单方面考虑,改造外窗比改造外墙具有优势;但以节能为基础热舒适为目的,改造外墙比改造外窗具有优势。围护结构不仅影响节能,还会影响建筑室内环境,综合对比,得到相对最优围护结构方案。     

体育馆天窗采光影响因素模拟分析

从体育馆自然采光要求出发,通过利用生态建筑设计软件Ecotect对不同天窗设置的模拟分析,对比天窗窗地比、天窗数量及间距等参数变化时室内场地不同的自然采光效果。分析其对采光系数、均匀度、光线方向性等的影响变化趋势,探讨对天窗自然采光的主要影响因素。     

Optimal sun-shading design for enhanced daylight illumination of subtropical classrooms

This study investigates the feasibility of fitting windows with sun-shadings in order to minimize the lighting power costs in daylight-illuminated classrooms lit from a single side in subtropical regions. An IES-CPC model is created of a representative classroom in Taiwan, and a series of simulations is performed to determine the average illuminance value and the uniformity of the illuminance distribution in the classroom under various lighting conditions with no sun-shadings fitted to the window. The numerical results are found to be in good agreement with the experimental measurements obtained using an array of nine-channel photometers. Having confirmed the validity of the simulation scheme, the illumination properties of four different sun-shading designs are considered. The results show that a double-layered sun-shading represents the optimal sun-shading design in terms of achieving a uniform illumination distribution within the classroom. Given appropriate physical dimensions, this daylight access device achieves the minimum illuminance requirement of 500 lx and improves the lighting uniformity ratio from 0.25–0.35 to 0.40–0.42. Furthermore, using this sun-shading device, the required illuminance ratio of 0.5 can be obtained simply by switching on one of the three rows of lights in the classroom. Accordingly, the daylight access device not only improves the illuminance conditions within the classroom, but also reduces the lighting power cost by 71.5% compared to the case where all of the lights are turned on.     

夏热冬冷地区办公建筑自然采光效果模拟分析

选取夏热冬冷地区苏州市某办公建筑作为模拟对象,采用Ecotect结合Radiance软件模拟建筑内自然采光情况,计算建筑内各楼层的平均自然采光系数与全自然采光百分比,分析玻璃可见光透射比、窗墙比对建筑自然采光效果和照明能耗节约量的影响。研究表明,采用可见光透射比较高的玻璃,适当增加建筑外窗面积,有助于提高建筑采光系数,改善自然采光环境,节约建筑照明能耗。     

An analysis of measured and simulated daylight illuminance and lighting savings in a daylit corridor

Lighting control integrated with daylighting is recognised as an important and useful strategy in energy-efficient building designs and operations. Prediction of the internal daylight levels is a key stage in daylighting designs. With the advances in computer technology, the computation of daylight illuminances can be conducted via lighting simulation program. This paper presents a study of the daylight coefficient (DC) approach using RADIANCE lighting software in simulating the indoor daylight illuminance of a corridor. The interior daylight illuminance data measured in the corridor were compared with the simulated results based on the computer software. It was found that the DC approach could give satisfactory results especially for the sun-shaded surface and sun-facing surface receiving a large amount of direct sunlight. Further, the daylight illuminance detected by the photosensor was also simulated in conjunction with measured daylight illuminance, dimming ratio and electric lighting power to predict the lighting energy savings. The findings suggested that the measured and predicted data showed a good agreement when large electric lighting savings resulted. The probable reasons causing the discrepancies were discussed.     

Evaluating the potential for energy savings on lighting by integrating fibre optics in buildings

The effective integration of an artificial lighting system and daylight in buildings occurs only when the artificial lighting system can be switched on or off as a function of daylight levels reaching the working surface of spaces. The paper considers fibre optics technology as a means of supplementing the daylight received at the rear of rooms and the subsequent integration of the total daylight received with a controlled artificial lighting system. Such an approach would contribute not only to energy savings but also to a reduction in environmental pollution. The evaluation took place using the climatic data from seven cities in Brazil and one in the UK. Results showed that by effectively integrating daylight from windows in buildings with the artificial lighting system, energy savings ranging from 17.7% to 92.0% could be achieved in the seven cities in Brazil and savings ranging from 10.8% to 44.0% could be achieved in the UK. By incorporating fibre optic technology into the system, the potential for energy savings on lighting was then found to range from 8.0% to 82.3% for the cities in Brazil and from 56.0% to 89.2% in the UK. For the city in the UK, it was further shown that there would be a reduction in carbon dioxide emission of 122 kg/m² of built area per year if daylight from windows were integrated with the artificial lighting system, and that this would increase to 138 kg/m² per year if fibre optics technology were to be installed.     

Assessing and predicting average daylight factors of adjoining spaces in atrium buildings under overcast sky

Daylight use in an atrium is particularly beneficial as the natural light can illuminate potentially dark core areas and decrease energy consumption from electric lighting. This study has investigated, for overcast sky conditions, the horizontal daylight levels in spaces adjoining atria and the vertical daylight levels on atrium well walls in atria. The daylight levels in the rooms and on the walls were derived from scale model measurements, theoretical calculations and predictions from the lighting simulation package Radiance. A comparison of measured data and modelling has validated Radiance simulations of atrium daylighting. The simulations show generally good agreement with theory while some limitations in the calculations used in determining the daylight factors in rooms with large widow area to total wall area ratios were observed. The average daylight levels in rooms displayed a linear relationship with the vertical daylight levels on the well wall. In terms of the well geometry and well façades (decided by the ratio of window area to solid wall area) and well surface reflectance, the variations of daylight level in the adjoining rooms have been analysed and some conclusions and design strategies for supporting preliminary design decisions are presented.     

Simulation-based assessment of the energy savings benefits of integrated control in office buildings

The purpose of this study is to use existing simulation tools to quantify the energy savings benefits of integrated control in office buildings. An EnergyPlus medium office benchmark simulation model (V1.0_3.0) developed by the Department of Energy (DOE) was used as a baseline model for this study. The baseline model was modified to examine the energy savings benefits of three possible control strategies compared to a benchmark case across 16 DOE climate zones. Two controllable subsystems were examined: (1) dimming of electric lighting, and (2) controllable window transmission. Simulation cases were run in EnergyPlus V3.0.0 for building window-to-wall ratios (WWR) of 33% and 66%. All three strategies employed electric lighting dimming resulting in lighting energy savings in building perimeter zones ranging from 64% to 84%. Integrated control of electric lighting and window transmission resulted in heating, ventilation, and air conditioning (HVAC) energy savings ranging from −1% to 40%. Control of electric lighting and window transmission with HVAC integration (seasonal schedule of window transmission control) resulted in HVAC energy savings ranging from 3% to 43%. HVAC energy savings decreased moving from warm climates to cold climates and increased when moving from humid, to dry, to marine climates.     

An analysis of daylighting performance for office buildings in Hong Kong

Daylighting has often been recognized as a useful source of energy savings and visual comforts in buildings. Occupants expect good daylight in their working spaces. The quality and quantity of natural light entering a building depend on both internal and external factors. In Hong Kong, commercial building accounts for the major building energy use and electric lighting is one of the major electricity-consuming items. This paper studies the daylighting performance and energy implications for office buildings. A total of 35 commercial buildings have been selected in the survey. Key building parameters affecting daylighting designs are presented. Two typical office blocks were further analysed based on a lighting simulation program. The daylighting performance was evaluated in terms of daylight factor, room depth and glare index. It has been found that the daylighting performance for office buildings is quite effective. About one-third of the office areas that are near the perimeter regions have an average daylight factor of 5%. For inner region of deep plan offices, some innovative daylighting systems such as light redirecting panels and light pipe could be used to improve the daylighting performance. In general, the office building envelop designs are conducive to effective daylighting and proper daylight linked lighting controls could save over 25% of the total electric lighting use.     

Influence of the coupling between daylight and artificial lighting on thermal loads in office buildings

The analysis of the global energetic needs in an office building has to take into account the daylight and artificial lighting which are tightly coupled. The luminous and thermal behaviours of a room are influenced by the artificial lighting that generates thermal loads and by the natural lighting coming from the windows. This paper deals with the foreseen energy balance of an office building with regards to the technological and architectural solutions. This study has been conducted with EDF Research and Development, Services, energies and living spaces Department. A global analysis is needed for a consistent approach of Energy Demand Save Management [Etude de l’influence de la complémentarité entre l’éclairage naturel et l’éclairage artificiel sur le comportement thermique des bâtiments tertiaires, Thèse Université de Savoie, March 2001, 213 pages].     

天然光利用的技术要求

详细讲解《全国民用建筑工程设计技术措施——电气节能专篇》“天然光的利用”一节的相关规定,包括:天然光的利用要求;对日光有较高要求的场所宜采用主动式导光系统,一般场所采用被动式导光系统;天然光导光、反光系统只能用于普通照明,不可用于应急照明;应避免将采光部分布置于阴影区内;不宜采用矩形、梯形、多边形断面的导光管;反射材料反射率不宜低于95%;宜减小天然光导光系统的长度和转弯次数;光导系统照度估算;当照度要求均匀且层高较高时,宜采用水平布置,一般情况应采用垂直布置;除特殊需要外,导光部件不宜采用光导纤维等。