夏热冬冷地区遮阳及自然采光节能优化设计

对于夏热冬冷地区,建筑外遮阳是一种非常有效的节能措施,不仅可以有效降低冷负荷,而且能够阻挡眩光,提供舒适的视觉环境,但是对自然采光有一定影响。借助能耗模拟软件Energyplus建立了上海某高层办公楼建筑模型,在采用自然采光和人工照明自动控制的条件下,模拟不同朝向采用不同形式的遮阳对建筑整体能耗及室内光环境产生的影响,通过比较后得出各个朝向的最佳遮阳形式。     

Effects of double glazed facade on energy consumption,thermal comfort and condensation for a typical office building in Singapore

Fully glazed facade that has been increasingly used in Singapore causes higher energy consumption and thermal discomfort due to higher solar gain. The use of double glazed facade system with ventilation system is one way to solve these problems. The objective of this paper is to investigate the effects of double glazed facade with ventilation system on the energy consumption, thermal comfort and condensation and compare to single glazed facade system. TAS and CFD software were utilized to calculate energy consumption, thermal comfort and condensation for single glazed facade building as well as double glazed facade building. The simulation results showed double glazed facade with natural ventilation were able to minimize energy consumption as well as to enhance the thermal comfort. Turning the mechanical fans on could also solve the condensation problem due to high humidity.     

天津生态城建筑遮阳应用案例浅析（一）

中新天津生态城指标体系要求100%为绿色建筑。建筑遮阳因其对建筑节能、室内热舒适与视觉舒适的效果显著,而成为绿色建筑必不可少的技术措施之一。生态城大量的建筑采用了外遮阳技术,本文选择部分典型的标志性建筑进行了浅析。     

Thermal behaviour of a ventilated double skin facade in hot arid climate

Modern Movement in architecture has resulted in a large number of high-rise buildings with glazed facades which increase the energy load of the buildings. To combat this phenomenon in colder climates, architects have turned to using double skin facades. These facades comprise of: a completely transparent external facade; an internal skin; and an air layer between the two. Research on the performance of double skin facades mostly considers cold and moderate climates. In addition, data collection is normally based on simulations, rather than actual field measurements. In this paper a building with double skin facade was monitored for 2 weeks in summer and 2 weeks in winter in the hot arid climate of Iran, in order to observe the behaviour of the facade both in hot and cold conditions. Additionally, simulations were performed on the case study building with and without double skin facade, to assess the effectiveness of the facade. The results revealed that the temperature difference between the outer skin, the inner skin and the cavity can significantly save heating energy in winter. To reduce the cooling loads in summer it is essential to introduce additional techniques such as night ventilation and installation of shading devices for the cavity.     

An internal assessment of the thermal comfort and daylighting conditions of a naturally ventilated building with an active glazed facade in a temperate climate

An active facade is often used to promote the flow of air through a building, however in order to ensure that this process is effective the facade should face a southerly orientation. This means that not only solar energy is transferred across the glazing but in sunny periods shading is needed to prevent excess brightness levels occurring on the working areas where it may result in the luminance distributions not complying with current lighting requirements. The building investigated is located in Sheffield, England and is one of the University of Sheffield's recently built green buildings. It has a high thermal mass which is used to promote the use of night cooling. This paper reports the initial findings of an internal assessment of the thermal comfort and daylighting conditions in such a building. The results have indicated that such designs are to be commended for their passive use of solar energy and can provide a high quality working environment.     

Simulation of ventilated facades in hot and humid climates

The Hong Kong climate is sub-tropical with hot and humid weather from May to September and temperate climate for the remaining 7 months period. A mechanical ventilation and air-conditioning (MVAC) system is usually operated to avoid the high temperatures resulting in high peak cooling loads. The facade design has a significant influence on the energy performance of office buildings. This work evaluates different ventilated facade designs in respect to energy savings.Thermal building simulations (TRNSYS) were linked to nodal airflow network simulations (COMIS) for detailed ventilated double-skin facade performance. In order to validate the model, simulations were carried out for an office building in Lisboa; the results were compared with measured data from the same building. The simulation results of surface and air temperatures show good agreement with the measurements. The results of the study can be used to reduce surface temperatures by using different materials for the roller blind that is positioned in the cavity of the double-skin facade. The results can further be used to reduce the high peak cooling loads during the summer period. This may result in significant energy savings and a reduction in the system's cooling capacity. It proved that a careful facade design can play an important role in highly glazed buildings and provides potential for energy efficiency.     

绿化遮阳对夏热冬暖地区建筑热环境影响分析

地处夏热冬暖地区的广西大部夏季湿热漫长,建筑空调制冷能耗高。通过对广西南宁市建筑外遮阳使用情况的调研,得到建筑立体绿化遮阳和非绿化外遮阳的使用情况。同时,选择一栋典型建筑,对其进行绿化遮阳及非绿化遮阳外墙表面温度的测试,分析绿化遮阳形式对建筑热环境的影响,探讨建筑绿化遮阳对广西乃至整个夏热冬暖地区建筑节能的作用。     

一种自然通风办公建筑主动式立面的环境评价

主动式立面经常在建筑中应用以促进建筑通风,为了保证这个过程的有效性,主动式立面必须朝南,然而这样,太阳辐射就会穿过玻璃直射室内,夏热季节则需要借助遮阳设施来遮挡,这可能会导致室内采光达不到标准。另一方面,采用主动式立面的建筑倾向于提高蓄热性能来强化夜间蓄冷效果,结果可能导致声回响时间延长,干扰人的工作。本文对采用主动式立面的办公建筑室内光、声和热环境性能进行测试评价,初步分析结果表明,主动式立面的优点是能够通过被动方式利用太阳能,提供高质量的工作环境,而如何确保空气流动路径通畅,以及如何采取相应措施减少声回响时间值得关注。     

ECOTECT能耗模拟下既有住宅建筑围护结构节能改造的热环境分析研究

目前,既有住宅建筑节能改造主要有围护结构改造和供热计量改造两方面。围护结构节能改造主要包括:外墙节能改造、外窗节能改造、屋面节能改造等技术措施的研究;建筑物围护结构节能改造除了能够降低建筑能耗之外,对建筑物室内热环境也有很大影响。采用ECOTECT能耗模拟软件,对西安市某住宅建筑围护结构不同节能改造方案的热环境进行模拟,深入分析不同节能改造方案的能源消耗、不舒适度、围护结构得热、温度分布和热舒适度情况,以热舒适为前提、节能为目的选择最优的节能改造方案。为既有住宅建筑节能改造方案优选提供依据。     

Energy simulation of vertical greenery systems

The objective of this research is to simulate the effects of vertical greenery systems on the temperature and energy consumption of buildings. Firstly, it involves performing TAS simulations to determine their effects on thermal comfort and energy consumption. It is found that 100% greenery coverage from vertical greenery systems is effective in lowering the mean radiant temperature of a glass facade building. Furthermore, to lower the energy cooling load significantly, the shading coefficient of plant species has to be low. Secondly, a thermal calculation of the envelope thermal transfer value (ETTV) to obtain their effects on the thermal performance of building envelope is performed. Results show a linear correlation between shading coefficient and leaf area index where a lower shading coefficient leads to a greater thermal insulation. 50% greenery coverage from vertical greenery systems and a shading coefficient of 0.041 reduce the ETTV of a glass facade building by 40.68%. Lastly, vertical greenery systems in mitigating the UHI effect within an estate is simulated using STEVE model. The increase of greenery coverage from vertical greenery systems is most significantly felt with a drop in the minimum estate air temperature throughout a large region of the estate.     

A combined system of chilled ceiling,displacement ventilation and desiccant dehumidification

Different types of heating, ventilation, and air-conditioning (HVAC) systems consume different amounts of energy yet they deliver similar levels of acceptable indoor air quality (IAQ) and thermal comfort. It is desirable to provide buildings with an optimal HVAC system to create the best IAQ and thermal comfort with minimum energy consumption. In this paper, a combined system of chilled ceiling, displacement ventilation and desiccant dehumidification is designed and applied for space conditioning in a hot and humid climate. IAQ, thermal comfort, and energy saving potential of the combined system are estimated using a mathematical model of the system described in this paper. To confirm the feasibility of the combined system in a hot and humid climate, like China, and to evaluate the system performance, the mathematical model simulates an office building in Beijing and estimates IAQ, thermal comfort and energy consumption. We conclude that in comparison with a conventional all-air system the combined system saves 8.2% of total primary energy consumption in addition to achieving better IAQ and thermal comfort. Chilled ceiling, displacement ventilation and desiccant dehumidification respond consistently to cooling source demand and complement each other on indoor comfort and air quality. It is feasible to combine the three technologies for space conditioning of office building in a hot and humid climate.     

Lichttechnisches und energetisches Verhalten von Fassaden moderner Verwaltungsbauten – Teil 1: Lichttechnisches Verhalten

Daylight and thermal energy performance of facades in office buildings, Part 1: Daylight performance. Regarding the impact on indoor illumination facade systems have to provide an appropriate visual indoor environment. In addition daylight penetrating the room through the facades should favourably influence the overall building energy balance. Daylight utilization can directly reduce energy consumption for electric lighting and can indirectly – due to the higher luminous efficacy of daylight compared to commonly used artificial lighting systems – reduce the thermal loads within the conditioned building spaces. In part 1 of this contribution the influence of different facade solutions on room illumination is systematically investigated by means of a parametric study of significant room, outdoor, environmental and climatic parameters for ten facade systems. The facade systems considered are conventional, permanently shaded, and light redirecting systems. The analysis of system performance is based on newly developed characteristics which allow the analysis and optimization of different facade systems under working conditions. Part 2 of the contribution shows the energetic interaction of the facade dependent internal loads by artificial lighting system and solar heat gains.     

外呼吸双层通风玻璃幕墙热工性能模拟分析

对某建筑外呼吸双层通风玻璃幕墙内的速度场和温度场进行了模拟分析。讨论了遮阳设施、空气层宽度等因素对综合传热系数的影响。分析比较了外呼吸双层玻璃幕墙建筑和四种单层玻璃幕墙建筑的供暖空调能耗。结果表明,外呼吸双层通风玻璃幕墙是一种节能的生态建筑围护结构形式。     

广州大学城建筑外遮阳节能效果分析

以广州大学城为例,综合介绍了广州大学城的外遮阳措施,运用透光系数Xs指标对其中的一栋典型建筑计算分析了遮阳效果,并通过全年逐时能耗模拟方法对该建筑的全年空调能耗进行了模拟计算,研究分析了外遮阳对建筑能耗的影响,对南方地区遮阳节能设计具有较好的指导作用.     

Energy simulations for glazed office buildings in Sweden

Highly glazed buildings are designed by architects to be airy, light and transparent with more access to daylight. Their energy efficiency, however, has become questioned. Therefore, energy simulations of single skin office buildings in Sweden were carried out, using a dynamic energy simulation tool. In order to study the impact of glass on the energy use during the occupation stage, office building alternatives with 30, 60 and 100% window to external wall area were studied. Other varied parameters were the building's orientation, the plan type (open and cell plan offices), the control set points and the façade elements (type and size of windows, type and position of shading devices, etc.). The main conclusion is that careful design is needed to ensure low energy use and good thermal comfort, especially for highly glazed office buildings. Careful design of glazed office buildings has to be based on detailed thermal simulations. Especially in fully glazed buildings (in which the façade is more “sensitive” to climatic conditions), proper combination of control set points, glazing and solar shading are crucial for the energy performance.     

夏热冬冷地区新农村住宅用能调查及能耗模拟

本文基于夏热冬冷地区新农村住宅用能调查,统计分析了新农村住宅的基本围护结构及功能分区等信息,了解住户主观热舒适评价,调查家庭能耗设备的拥有量及使用情况,并在此基础上选取典型夏热冬冷地区新农村住宅进行能耗模拟,得到住宅基本能耗及能耗结构特点.结果表明,住户对农宅的通风、采光评价较高,而保暖、遮阳评价较低;随着新农村家电设...     

A study of the effectiveness of passive climate control in naturally ventilated residential buildings in Singapore

Singapore has the hot and humid climate throughout the year. Many passive climate control methods are adopted in the naturally ventilated residential buildings to help achieve thermal comfort and reduce the energy consumption of air-conditioning. A field measurement and computational energy simulations were conducted to examine the effectiveness of commonly used passive climate control methods for these buildings. The effect of building orientation, façade construction, special roof system and window shading device on indoor thermal environment and cooling load was studied. The surface temperature of external wall and indoor thermal environment was measured to analyze the façade thermal performance. The cooling load was simulated to evaluate the effectiveness of various passive climate methods. Using the special roof system as thermal buffer is the most efficient method to reduce the room cooling load.     

Assessment of the thermal and visual efficiency of solar shades

Solar shades are efficient architectural elements in order to reduce the thermal loads inside buildings. In one way, they can reduce significantly the energy needs of cooling systems. But in other way, they can decrease the visual comfort and increase the energy consumption of artificial lighting. Actually, the sizing of shading devices is mainly a thermal optimization process. The efficacy of solar shades must be assess taking into account both thermal and visual point of view.     

Comparison of low-energy office buildings in summer using different thermal comfort criteria

Sustainable low-energy office buildings attempt to harness the buildings architecture and physics to provide a high quality working environment with the least possible primary energy consumption. A promising approach to condition those buildings in summer employs the utilization of the building's thermal storage activated by natural heat sinks (e.g., ambient air, ground water or soil) through night ventilation or thermally activated building systems (TABS). However, a certain room temperature cannot be guaranteed as occupants may influence the room energy balance by window opening, internal heat gains or sun shading control. Between 2001 and 2005, monitoring campaigns were carried out over 2 or 3 years in 12 low-energy office buildings which are located in three different summer climate zones in Germany. These climate zones are defined as summer-cool, moderate and summer-hot. The weather at the building site and the room temperatures in several office rooms were monitored by different scientific teams. The raw data are processed for data evaluation using a sophisticated method to remove errors and outliers from the database and to identify the time of occupancy. The comfort in all office rooms in each building is evaluated separately. For data presentation, these separate comfort votes per office room are averaged using the median instead of the arithmetic mean in order not to overestimate extremely cold or hot room temperatures. A comfort evaluation in these 12 low-energy office buildings indicates clearly, that buildings which use only natural heat sinks for cooling provide good thermal comfort during typical and warm summer periods in Germany. However, long heat waves such as during the extreme European summer of 2003 overstrain passively cooled buildings with air-driven cooling concepts in terms of thermal comfort.     

夏热冬冷地区水平遮阳板深度与建筑能耗之间的关系

国内夏热冬冷地区建筑门窗能耗较大,为了探讨夏热冬冷地区合适的外窗遮阳技术,通过对夏热冬冷地区典型城市上海和浙江湖州地区典型建筑遮阳技术进行调研发现,两个地区常采用的遮阳方式为水平遮阳板。在调研基础上建立建筑能耗分析模型,采用DeST能耗模拟软件分析上海和浙江湖州地区外窗水平遮阳板深度与建筑能耗之间的关系,为夏热冬冷地区遮阳改造提供一定的指导。