CFD assessment of the performance of lateral ventilation in Double Glazed Façades in Mediterranean climates

Implementation of Double Glazed Façades (DGF) in buildings has been an object of broad study and application in recent years, both in new and existing constructions. However, there is little experience in predicting the operating behavior of a DGF. Sometimes the results obtained are not satisfactory and an extra energetic cost is necessary to obtain suitable comfort conditions in the inner space of the building, especially in Mediterranean climates, where large solar gains are a constant condition along throughout the year, and such large semi-transparent areas can produce significant over-heating in buildings. Computational Fluid Dynamics (CFD) has proven to be a useful tool for modeling air flow and heat transfer in DGF including conduction, convection and radiation heat transfer phenomena. The aim of this work was to evaluate, by means of CFD, the influence of several lateralventilation systems including the variation of the flow inlet (e.g., uniform or swirl flow inlet) and analyzing different inlet flow configurations (e.g., uniform, inclined, upper or lowercrossed inlet flow). From these CFD simulations, a comparative efficiency study, in terms of reduction of solar load gains and energetic requirements, was performed comparing the obtained results for horizontal ventilation against vertical ventilation, which was previously studied by this research group. It was found that using horizontal ventilation schemes would reduce the required air volumetric flow rate within the DGF for obtaining similar reductions in solar load gain to those obtained with vertical ventilation, when the construction and operation parameters of the DGF are equal for both cases.     

Optimization of indoor air temperature set-point for centralized air-conditioned spaces in subtropical climates

Current Building Management System (BMS) does not integrate well with real-time occupant response. In order to fine-tune the system to meet individual demands and to maximize the occupant acceptance of indoor thermal environment, a new notion of Bayesian control algorithm was developed in this study. Control parameters of a weighting function for air temperature control (namely, the control temperature constant k_T and the probable acceptance of the air temperature set-point λ) and two prior distribution functions of air temperature set-point, namely the uniform prior and the expert's prior, were examined. Optimum air temperature set-points of air-conditioning systems obtained from certain Hong Kong offices were then used to demonstrate the applicability of the new algorithm for controlling an example air temperature set-point ranged between 0.2 °C and 1 °C. This algorithm would be useful for adaptive thermal comfort control in a large, post-occupied air-conditioned space.     

瓷砖的十八般武艺

佛山以武术盛名，试看黄飞鸿的“无影腿”，就踢遍了大江南北，同时佛山也以陶瓷扬名，在陶瓷的产业链上，多少室内设计师，也用瓷砖练就了一身武艺。当大多数设计师只关注如何用瓷砖砌墙铺地的时候，却有室内设计师蹲坐在造砖师傅的旁边，为瓷砖的第二次加工，费尽心思，温少安就是如此。     

真空玻璃房间与普通玻璃房间的CFD模拟对比研究

简要介绍了真空玻璃产业的现状及展望.采用计算流体动力学(CFD)数值模拟的方法,以西安夏季某空调房间为模拟研究对象,模拟真空玻璃窗房间和普通玻璃窗房间的温度场和速度场的分布,并进行了对比研究.建筑玻璃窗采用真空玻璃,在合理安排气流组织的条件下降低了夏季室内冷负荷,和普通玻璃比较能够起到很好的节能效果.     

釉面水泥材的研制

本文研究了水泥胶砂受热强度及外掺粉料对其强度的影响。并在此基础上成功地研制出具有较高强度的不同颜色的釉面水泥材。探讨了影响釉面水泥材釉面质量的因素。     

彩釉石英漆的研制

采用陶瓷成釉的原理，使石英砂成釉上色，烧制出数十种色彩艳丽的彩釉石英砂。再利用彩釉石英砂与无皂轧液、各种助剂配合生产彩釉石英漆，利用彩釉石英砂与天然彩砂复合，生产复合彩釉石英渗。该产品具有环保、色彩丰富、不易褪色的装饰效果。     

Buildings for hot climates

Climatic conditions determine the kind of buildings that are provided, but there are planning implications also, since cities can in turn affect the local climate. Making a virtue of necessity is the theme of this survey of the problems by the Head of the Environmental Engineering Department of the Technion, Israel.     

Buildings for hot climates

Climatic conditions determine the kind of buildings that are provided, but there are planning implications also, since cities can in turn affect the local climate. Making a virtue of necessity is the theme of this survey of the problems by the Head of the Environmental Engineering Department of the Technion, Israel.     

Movable roof insulation in hot climates

This paper presents the results of experiments on the effect of a system of movable insulation - with and without a roof pond - on temperature and heat flow at the ceiling surfaces of air conditioned and unconditioned rooms in buildings roofed with thick reinforced concrete which are exposed to extremes of hot and cold weather. Results indicate that there is considerable merit in adopting such a system, particularly in hot, dry conditions, in addition to the limited benefits of harnessing solar energy in winter conditions.

The experiments were carried out at the Central Building Research Institute, Roorkee, UP, India. Mr Rao is at present working as an associate professor in the Department of Building Science, Faculty of Architecture, University of Singapore.     

Movable roof insulation in hot climates

This paper presents the results of experiments on the effect of a system of movable insulation – with and without a roof pond – on temperature and heat flow at the ceiling surfaces of air conditioned and unconditioned rooms in buildings roofed with thick reinforced concrete which are exposed to extremes of hot and cold weather. Results indicate that there is considerable merit in adopting such a system, particularly in hot, dry conditions, in addition to the limited benefits of harnessing solar energy in winter conditions.

The experiments were carried out at the Central Building Research Institute, Roorkee, UP, India. Mr Rao is at present working as an associate professor in the Department of Building Science, Faculty of Architecture, University of Singapore.     

流光溢彩--浅议坡屋面琉璃制品

叙述了我国古建筑广泛应用的琉璃制品的种类、规格及应用。     

举足轻重的北欧景观设计

城市实验室强调当代城市发展中儿童和年轻人的利益,并重点关注挪威城市的社会与物质环境。城市中心区人口的融合城市实验室以一种社会视角来考察建筑。近来在城市与住宅开发中出现了一批品质低劣的公共空间,它们尤其忽视了儿童及青少年的利益,而城市实验室的创建可被视为对此的一种回应。在挪威,许多城市中心的人口构成单一,居民主要是二十多岁的年轻人或是六十多岁的长者。城市中心的人口融合能够促进城市的多元化并增进社     

Extreme wind speeds in mixed climates revisited

The methodology for the analysis of extreme wind speeds in mixed climates originally proposed in 1978 by Gomes and Vickery is updated to take advantage of recent improvements in methodology and available data records. The revised methodology is demonstrated for two sites in Australia: Onslow and Brisbane. This work shows that the observed curvature in the upper tail is due to incomplete convergence to the Fisher-Tippett Type 1 asymptote and is not an indicator of Type 3 behaviour as sometimes supposed. It is also shown that moving from a reference epoch of 1 year to an epoch of 50 years frees the method from most of the rate-dependent assumptions, and simplifies the problem to a single, dominant wind mechanism.     

伦敦维多利亚与艾伯特博物馆的玻璃屋顶

维多利亚与艾伯特博物馆是世界上最伟大的设计与应用艺术博物馆之一。博物馆展览空间面积为45000m^2,分为145个房间,总共有约400万件藏品。2001年博物馆实行了“未来计划”,这是一个通过翻新使建筑寿命延长10年的概念。     

Extreme wind speeds in mixed wind climates

In this paper, a technique is discussed which enables extreme wind speed probabilities in mixed wind climates to be determined. It is shown that in such wind climates the method is likely to yield more accurate probability estimates than the traditional Gumbel analysis of annual wind speed maxima, particularly for annual probabilities of less than 2% (i.e. return periods greater than 50 years). The technique requires a separate analysis of each significant wind-producing meteorological phenomenon and practical methods of achieving this are presented. Extreme wind speed parameters obtained from each analysis may then be combined to yield a “composite extreme wind speed diagram” and several examples illustrating this procedure are shown. By means of a numerical simulation of a typical mixed wind climate, a detailed study is made of the distribution of extreme wind gusts from different meteorological phenomena. This study indicates that a Gumbel analysis of 20 annual maxima may severely underestimate low annual probability (i.e. long return period) gust speeds.     

闪耀千年的光彩——釉面陶瓷的复兴

在过去的数千年里,釉面陶瓷成为庙宇、教堂和宫殿选择使用的材料。20世纪初,当全玻璃外立面成为可实现的建筑形式时,现代派认为结构构件应该是可见的,这样一来,神秘、具有遮挡作用的装饰瓷砖——就像东方的地毯一样——将永远远离高雅的建筑。然而。     

Housing finance in the Nordic countries

The aim of this article is to describe and compare the housing finance systems in the Nordic countries from a housing policy perspective. The starting point is the obvious similarity between the countries in economic, cultural, geographical and historical respects. While a housing consumption goal is important to all these countries and in spite of their similarities, the countries have chosen quite different housing finance systems.

It is suggested that one explanation of these differences is different methods of targeting or selectivity. Nevertheless, some countries do have a more selective policy than others. One explanation may be differences in the housing stock. It is observed that countries with a high share of selective subsidies do not have a public, non‐profit housing sector. The paper ends with a discussion of the need for more research in this important area.     

Passive cooling of cement-based roofs in tropical climates

In tropical climates, dwellings are made of cement-based materials like concrete to be able to withstand tropical storms and severe weather conditions. However, cement-based materials exhibit undesirable thermal properties including low thermal conductivity and thermal diffusivity which make living conditions almost unbearable. The purpose of this research project was to investigate the impact of a newly designed passive cooling system which can minimize heat transfer through concrete roofs. The passive cooling system consists of a corrugated aluminum sheet with a unique orientation to promote heat dissipation. A layer polyurethane is also used to minimize heat transfer. Experimental results based on lab-scale prototypes show that the well-designed roof insulation system can reduce the typical thermal load by over 70%. The passive cooling system also shows a desirable slow response time to irradiation, which is a desirable characteristic necessary to effectively control thermal fluctuations and reduce thermal loads simultaneously. The results also indicate that the cement-based roof midpoint temperature can be modeled accurately using an appropriate empirical model.