Application of advanced glazing to high-rise residential buildings in Hong Kong

The energy saving that can be achieved by applying advanced glazing to a typical high-rise residential building in Hong Kong was evaluated using the simulation software EnergyPlus. It was found that application of low-e glazing would lead to a reduction in cooling electricity use by up to 4.2%. The saving due to application of low-e reversible glazing would be up to 1.9%; double-clear glazing up to 3.7%; and clear plus low-e glazing up to 6.6%. The achievable saving would depend on orientation of building wings, and type and location of rooms. The analysis suggests that for the high-rise public housing blocks in Hong Kong, the use of expensive advanced glazing would not be economically viable from the point of view of saving in cooling energy cost.     

Application of overhangs and side fins to high-rise residential buildings in Hong Kong

For a typical lone high-rise 20-storey residential building in Hong Kong, the extent to which cooling of its 10th-floor (mid-level) rooms depends on overhangs and side fins was evaluated. By using the software EnergyPlus?, it was found that the application of overhangs would reduce the electricity consumption by up to 5.3%. The highest reduction was obtained in rooms with windows unshaded by own-wing walls, face west, and have 0.75 m overhangs. By using the same software, it was found that the application of side fins to the building with overhangs would reduce the electricity consumption by up to 1.4%, where the highest values belong to windows facing either north or south (at west wing), with out-of-core side fins.     

Cooling energy evaluation for high-rise residential buildings in Hong Kong

Based on the design of a typical high-rise public housing block in Hong Kong, the dependence of space cooling loads of residential flats on the constructions of external walls and partitions, and the location of thermal insulation layer in the walls and partitions, was studied by detailed simulation. The results show that insulating the envelope and the partitions would be effective in reducing the yearly space cooling load, by up to 38%, but could either increase (by up to 19%) or reduce (by up to 16%) the peak cooling demand, depending on the number and positions of insulation layers in the walls. Reducing the thermal capacity of the envelope and partitions (e.g. by reducing their thickness) would lead to large increases in the peak cooling demand, by more than 60% in the extreme case.     

Energy performance of windows in high-rise residential buildings in Hong Kong

At the present time in Hong Kong in its hot and humid climate, a single pane, clear glazing is most often used in windows of tall residential buildings. During this study, we employed HTB2, detailed building heat transfer simulation software, to evaluate a decrease in the yearly cooling load (Q) and in the peak cooling-load (D) in two residential flats due to different glazing single pane types and different flat orientations. The investigated glazing types were clear glazing, tinted glazing, reflective glazing, and tinted and reflective glazing.     

Modeling water consumption and flow rates for flushing water systems in high-rise residential buildings in Hong Kong

The probable maximum flow rates and flushing water consumption of a residential development are two crucial design factors for flushing water plants and evaluation of the risk of overloading them. Flushing water demands are transient and influenced by occupant load variations, occupant usage patterns, installed appliances and system commissioning. This study proposes mathematical expressions to determine the water consumption and flow rates for flushing water systems of residential buildings in Hong Kong. The model parameters were identified from a recent survey on the water closet (WC) usage patterns of 14 high-rise residential buildings. The occupant load factor, diurnal variation of flushing, discharge and refilling durations and volume of the WC cistern recorded from 597 households were used to determine the uncertainties of consumption and flow rates, and hence the risk of overloading a plant. Predictions were made for two typical residential buildings in Hong Kong. Good agreement between the predicted and the measured flushing water consumption was found. This model would be useful in calculating the capacity of a flushing water plant and the associated risk of overloading it.     

Influence of thermal insulation position in building envelope on the space cooling of high-rise residential buildings in Hong Kong

At the present time, thermal insulation is almost not used in fabric of tall residential buildings in Hong Kong, as their fabric slabs usually comprise concrete layer covered on each side by plaster layers. This study investigates into the influence of an existence of the thermal insulation layer in the outside walls on the yearly cooling load and yearly maximum cooling demand in two typical residential flats in a high-rise residential building by employing HTB2, detailed building heat transfer simulation software. During the investigations, the thermal insulation layer up to 15 cm thick was placed either at the inside, or at the outside, or at the middle part of the outside wall structure. Then, the concrete layer was up to 40 cm thick. The simulation predictions indicate that the highest decrease in the yearly cooling load of up to 6.8% is obtained when a 5 cm thick thermal insulation layer faces the inside of the residential flat. The highest decrease in the yearly maximum cooling demand of 7.3% is recorded when a 5 cm thermal insulation layer faces either the outside or the inside of the flat; this depends on the flat orientation. However, much weaker reductions in the yearly cooling load and yearly maximum cooling demand are found when the thickness of thermal insulation is increased above 5 cm and the thickness of concrete is increased above 10 cm.     

Benchmarking Hong Kong and China energy codes for residential buildings

Mandatory energy codes to curb energy use of residential buildings have been formally launched in China for more than two decades but little has been publicized in literature. Similar codes are not available for residential buildings in Hong Kong, but most residential buildings in Hong Kong, especially public housing estates, are HK-BEAM certified to demonstrate their compliance with regulatory and basic design requirements. Given HK-BEAM is internationally recognized and there are doubts about the effectiveness of the China codes, how the energy efficiency of the HK-BEAM certified buildings compare with buildings in compliance with the China codes is of interest to most building designers and policy makers. This paper describes how the energy efficiency of a case study building in compliance with the China codes compare with the one in compliance with HK-BEAM. The energy simulation by HTB2 and BECRES reveal that the case study building in compliance with the China codes is 51.1% better in energy use. In the study, the relative impact of each compliance criterion on energy use and cooling load has been quantified by sensitivity analysis. The sensitivity values indicate that energy use is most sensitive to air-conditioning operation hours, indoor design temperature, coefficient of performance (COP) of the room air-conditioners (RAC) units, and the envelop characteristics. The results of this study indicate that a HK-BEAM certified building cannot satisfy the China codes requirements. This provides good reference to the policy makers, the building owners, and to the China and Hong Kong Governments when considering reciprocal recognition of building energy codes.     

Ventilation of air-conditioned residential buildings: A case study in Hong Kong

More and more studies reported that there were insufficient ventilation and excessive CO_2 concentration in air-conditioned residential buildings, but few solutions were provided. This study investigates the overnight evolution of CO_2 concentration in air-conditioned residential buildings and then focuses mainly on the evaluation of three ventilation strategies, including overnight natural ventilation, short-term mechanical ventilation and short-term natural ventilation. On-site measurements were conducted in a typical residential bedroom in Hong Kong in September. The indoor and outdoor CO_2 concentration, air temperature and relative humidity as well as the outdoor wind speed during the measurements were analysed. Ventilation rates were calculated based on the time series of CO_2 concentration. This study confirms that additional ventilation is usually needed in air-conditioned residential buildings. Overnight natural ventilation with even a small opening is associated with excessive energy consumption and deteriorated indoor thermal environment. Short-term natural ventilation strategies are inefficient and uncontrollable. Compared to the best short-term natural ventilation strategy, a reasonably designed short-term mechanical ventilation strategy requires only a 41% of ventilation period to complete one full replacement of indoor air and to reach a lower indoor CO_2 concentration. Nighttime case studies and a theoretical analysis suggest that a few several-minute mechanical ventilation periods could potentially maintain an acceptable indoor air quality for a normal sleeping period of 8 h.     

Daytime urban heat island effect in high-rise and high-density residential developments in Hong Kong

Nearly 60% of electrical energy use in Hong Kong is for space conditioning during summer months. The paper investigates the impact of design-related variables on outdoor micro level daytime heat island effect in residential developments in Hong Kong. The paper hypothesizes that the differences in outdoor temperatures within and between residential developments can be explained by the impact of design-related variables on the overall environment. Case studies of three large housing estates reveal urban heat island effect (UHI) in the order of 1.5 °C within an estate, and 1.0 °C between estates. The results indicate that energy efficient designs can be achieved by manipulating surface albedo, sky view factor and total height to floor area ratio (building massing) while maximizing cross ventilation.     

谈高层商住楼的建筑设计

结合太铁职工文化活动中心综合改造项目实例,从总平面规划布局、平面布局、空间组合设计、防火分区等方面,阐述了高层商住楼的建筑设计方法,并阐明了疏散和消防对高层建筑的重要性。     

谈高层居住建筑公共空间设计

归纳了目前我国高层居住建筑公共空间设计中存在的问题,并针对各问题的产生原因,分析了公共空间设计不合理导致的后果,提出了几点改善高层居住建筑公共空间环境的建议,有利于营造出舒适且人性化的生活环境。     

设有空中花园的高层住宅建筑自然通风的研究

对设有空中花园的建筑群内流场进行了数值模拟，分析了来流方向、建筑物间距、建筑物高度及空中花园体积等因素对建筑物自然通风的影响。模拟结果表明，在上游建筑物上设置空中花园可以改善下游建筑物的自然通风效果；在第1排建筑物上设置空中花园和在前2排建筑物上设置空中花园，对下游建筑物自然通风的影响没有明显区别。     

地暖在高层住宅楼中的应用

介绍了地暖在某高层住宅楼的应用，分析了地暖的组成、施工工艺要求以及优缺点，并提出了一些地暖发展的建议，展望了低温地板辐射采暖在我国的发展，以提高人们对地暖的认识，推广地暖的应用。     

浅析如何加强高层住宅建筑小区的消防安全管理

高层住宅容纳的人数较多,而且对建筑各项设备的要求是更加的严格,为了保证居民生命财产以及建筑物的安全,从目前高层建筑小区消防安全管理存在的问题开始着手,浅谈如何加强高层住宅建筑小区的消防安全管理措施。     

Lowering the outdoor temperature in high-rise high-density residential developments of coastal Hong Kong: The vegetation influence

This paper investigates the impact of on-site variables on the influence of vegetation in lowering outdoor temperature. The study uses six critical on-site variables such as surface albedo, sky view factor, altitude, shrub cover, tree cover and average height to floor area ratio to carry out analysis in five data sets. The climatic parameters and physical characteristics were measured and surveyed, respectively in 216 stations in high-rise high-density residential developments of coastal Hong Kong. The data set is mainly categorised into peak summer clear sky days (PSCS-days), peak summer partially cloudy days (PSPC-days) and late summer days to address the issues related to cloudy sky conditions in Hong Kong. The trend analysis shows that at a lower sky view factor, ranging from 0.1 to 0.25, shrub cover as low as 10–15% in a 1000 m² open area is more effective in reducing outdoor temperature than the same level of tree cover in a location with a higher sky view factor (0.4 or above). The regression models used in this study were able to explain the influence of on-site variables on vegetation in lowering the outdoor temperature within the respective urban settings. In high-rise high-density environments, on-site variables such as sky view factor and altitude have a substantial impact on the influence of vegetation in lowering outdoor temperature. However, off-site variables such as high urban density and anthropogenic heat could negate the behaviour of sky view factor and altitude. The study suggests that increasing the tree cover from 25% to 40% in the pocket parks in coastal area residential developments of Hong Kong could reduce daytime urban heat island intensity (UHI) by further 0.5 °C.     

高层住宅建筑外墙外保温体系构造分析

结合住宅工程实例,对外保温体系进行了分析,分别介绍了保温材料使用要求,施工工艺,重要节点做法等内容,通过采取有效的构造措施,杜绝了火灾隐患,防止了＂冷、热桥＂现象的发生。     

改性EPS保温板在高层住宅中的应用

结合具体的工程经验,分析了改性EPS保温板的特性和应用于高层住宅的可行性,并且在经济性、适用性、耐久性等方面进行了阐述,对具体的施工工艺进行了介绍,以期促进改性EPS保温板的推广应用。     

高层住宅建筑消防车通道的管理探讨

随着城市化的进程不断加快,城市人口的密度越来越大,导致房屋供不应求.在此基础上,房地产行业取得了迅猛的发展,城市中高楼林立,高层建筑数量和规模不断扩大,这正是城市发展的客观表现,与此同时,也存在着严重的消防安全问题.文章主要针对高层住宅建筑消防车通道的管理进行分析,结合目前建筑设计防火方面的实际情况,对高层住宅建筑中存在的火灾危险性进行分析,总结相关的经验,提出高层住宅建筑消防车通道的有效管理方式,希望能够为其他的高层建筑消防车通道管理工作有序开展提供参考依据,保障高层建筑使用的安全性,防止火灾问题的产生.