Passive solar systems for heating, daylighting and ventilation for rooms without an equator-facing facade

Spaces without northerly orientations have an impact on the ‘energy behaviour’ of a building. This paper outlines possible energy savings and better performance achieved by different zenithal solar passive strategies (skylights, roof monitors and clerestory roof windows) and element arrangements across the roof in zones of cold to temperate climates typical of the central and central-southern Argentina. Analyses were undertaken considering daylighting, thermal and ventilation performances of the different strategies. The results indicate that heating, ventilation and lighting loads in spaces without an equator-facing facade can be significantly reduced by implementing solar passive strategies. In the thermal aspect, the solar saving fraction reached for the different strategies were averaged 43.16% for clerestories, 41.4% for roof monitors and 38.86% for skylights for a glass area of 9% to the floor area. The results also indicate average illuminance levels above 500 lux for the different clerestory and monitor arrangements, uniformity ratios of 0.66–0.82 for the most distributed arrangements and daylighting factors between 11.78 and 20.30% for clear sky conditions, depending on the strategy. In addition, minimum air changes rates of 4 were reached for the most extreme conditions.     

Luminous impact of balcony floor at atrium spaces with different well geometries

The atrium concept allows the exploitation of daylighting by bringing natural light into the center of the buildings, thus enhancing a more even distribution of daylight. The configuration of interior balconies, however, is determined based on the purpose of the interior space and the use of the building, which may defeat the primary daylighting advantages inherent in the atrium concept. The authors have developed insights regarding the critical daylighting performance factors by evaluating the relative effect of various interior balcony configurations on illumination level and its distribution with different atrium geometries. For these, parametric measurements of illumination level with a scale model of a four-sided atrium building and various interior balcony configurations have been conducted under diffuse sky conditions within the sky simulator at a Texas university. This paper represents the atrium performance results in terms of daylight factor, Well index, balcony Well index, the configuration of interior balcony; and the results are compared with basecase atria without any interior balcony. As expected, Well index and balcony depth are the most significant factors in daylighting performance in atrium spaces with interior balconies. For the position not covered by balcony, adequate illumination can be achieved for circulation regardless of building Well index and balcony depth although it may be that involved well indices are relatively low. On the other hand, light attenuation on the position under balcony floor is up to 70–90%, in particular, when the Well index becomes higher than 1 m and balcony floor becomes deeper than 3 m.     

建筑大底盘的自然通风采光

建筑设计采用下沉式庭院、天窗、天井等形式达到建筑大底盘地下车库的通风采光,可降低污染、减少能耗。     

Skylight for Interior Lighting Design

It is inevitable for indoor lighting design to render a room lit by natural light, especially for an atelier or an indoor pool where there are many windows. This paper proposes a method for calculating the illuminance due to natural light, i.e. direct sunlight and skylight, passing through transparent planes such as window glass. The proposed method makes it possible to efficiently calculate such illuminance accurately, because it takes into account both non-uniform luminous intensity distribution of skylight and the distribution of transparency of glass according to incident angles of light. Several examples including the lighting design in an indoor pool, are shown to demonstrate the usefulness of the proposed method.     

天空光偏振模式自动探测装置

为了获得较高的天空偏振光导航精度,研究了天空光偏振模式的模型。设计了天空光偏振模式自动探测装置,用于获取大量的天空光偏振模式信息并构建天空光偏振模式模型。该装置克服了传统天空偏振光分布模式探测仪器操作繁琐,效率低的缺点,利用计算机控制角度旋转和相机拍照协同工作,能够简单快捷地实现一键采集一组天空偏振图像。测试显示,该装置能够准确地在预期位置完成偏振图像的采集工作。获得的图像偏振模式明显,对于光强度的探测精度优于0.237 5(3σ)灰度值(8 bits),平均每个测量点耗时3.02 s,采集效率较传统偏振模式探测仪器大为提高,能够实现天空光偏振模式的有效探测。     

Occurrence of standard skies during typical daytime half-days

The current trials to introduce new daylight assessment criteria for future building designs as well as for renewable energy simulations with the trend to implement annual daylight profiles for a specific locale or region need more detail information on the exterior daylight conditions. Bratislava is the only locality in Central Europe where a CIE-IDMP general station is recording 1-min regular daylight measurements since 1994 and 10-year data gathered can be used now to derive models valid for wider regions. In this paper, the analysis of measurements and sky-type occurrence is representing daylight conditions only for this single site. As the meteorological net of observatories register sunshine duration for longer periods worldwide, also this information may serve as the basis for modelling exterior daylight illuminance courses as well as typical sky conditions when no other measurements are available. Furthermore, the new General Sky Standard adopted by CIE in 2003 and by ISO in 2004 gives the possibility to study actual skies occurring under four characteristic daylight situations associated with sunshine duration during typical half-days.     

建筑产业化的探索与实践——万达广场采光顶产业化小记

建筑产业化是以标准化设计、工厂化生产、装配化施工和信息化管理为主要特征的建筑生产方式。通过探索和实践,万达广场采光顶在标准化设计基础上,研发了适应工厂化生产和装配化施工的工艺流程,并纳入了BIM建筑信息化管理,从而较为全面地实现了产业化要素。文章从研发和试点两个方面对采光顶产业化过程进行了总结,以期为后续产业化工作的进一步深入奠定基础。     

多种天气条件下的天空光偏振模型

天空光偏振模型能够仿真天空光偏振态的分布规律,是研究天空光偏振态分布与大气特性参数之间的定量关系的重要工具.首先,基于倍加累加法的辐射传输模型和T矩阵法计算粒子散射特性,建立了适用于多种天气条件下的天空光偏振模型,可覆盖可见光波段到近红外波段;其次,在比较实验中,所建立模型的仿真结果与Hovenier等人的计算结果有95%的全天空光仿真点的相对误差小于5%;最后,利用基于液晶相位可变延迟器(liquid crystal variable retarders,LCVR)的全偏振成像探测系统进行全天空光探测实验,结果表明,所建模型的仿真精度优于传统模型,并且在80%的区域内与实际观测结果保持一致.由此可以得出结论,所建立的天空光偏振模型能够比较准确模拟多种天气下的全天空范围内天空光偏振态分布规律,为不同天气条件下偏振遥感探测和偏振导航等技术提供有力的理论依据.     

Modeling of Skylight and Rendering of Outdoor Scenes

Photorealistic animated images are extremely effective for pre-evaluating visual impact of city renewal and construction of tall buildings. In order to generate a photorealistic image not only the direct sunlight but also skylight must be considered. This paper proposes a method of high-fidelity image generation for photorealistic outdoor scenes based on the following ideas:

• 1 The intensity distribution of skylight taking account of scattering and absorption due to particles in the atmosphere which coincides with CIE standard skylight luminance functions is sought, and realistic images considering about spectrum distribution of skylight for any altitude of the sun can be easily and accurately displayed.
• 2 A rectangular parallelepiped with a specialized distribution of intensity simulating the skylight is introduced for efficient calculation of illumination due to skylight, and by employing a graphics hardware calculation of the skylight illuminance taking into account shadow effects is obtained with high efficiency; these techniques can be used to generate sequences of images, making animations possible at far lower calculation cost than previous methods.