ctbuh.org/papers Title: Author: Subjects: Sustainability Strategy LiJun Cao, Environmental Market Solutions, Inc. Building Case Study MEP Sustainability/Green/Energy Publication Date: 2014 Original Publication: Paper Type: Suzhou Zhongnan Center: In Detail 1. Book chapter/part chapter 2. Journal paper 3. Conference proceeding 4. Unpublished conference paper 5. Magazine article 6. Unpublished Council on Tall Buildings and Urban Habitat / LiJun Cao
Sustainability Strategy 可持续性策略 LiJun Cao, Environmental Market Solutions, Inc. 曹丽君, 君凯环境管理咨询 ( 上海 ) 有限公司 HaiTao Li, Zhongnan Group 李海涛, 中南建设控股集团 This chapter explores methodologies and approaches for achieving sustainable design for megatall buildings, through the review of various sustainable design elements that will be implemented in the Suzhou Zhongnan Center. Based on the stipulations of LEED CS 2009, the design team established targets for reducing energy demand, which will be achieved through elements such as ice storage, optimization of façades and fenestration, and targeted distribution of the HVAC systems and chiller plants. In addition, greywater and rainwater recycling programs are pursued. 本节通过分析苏州中南中心中应用的各种可持续设计元素, 探讨了实现超高层建筑可持续设计的方法论和途径 根据 LEED CS 2009 中的要求, 设计团队将降低能源需求作为目标, 并将通过冰蓄冷, 外墙和开窗方式, 以及合理分布 HVAC 系统与冷却塔的方式来实现此目标 另外, 团队还将进行灰水及雨水回收利用的项目 Energy Design Energy-saving design is always at the core of a green-building concept. Particularly for megatall buildings, energy savings involve the extensive investments made in lighting, ventilation, cooling and heating systems. The starting point for reducing energy consumption is to optimize performance of the building envelope. The optimized building envelope had been achieved by a comparative study of the typical floor s energy consumption, then reviewing various options. Demand Reduction Based on the requirement of LEED CS 2009, the design team established the following targets. The energy consumption of MEP systems should be decreased by 20% in comparison with the latest Chinese energy code. The annual energy cost of the building should be decreased by 16% compared with ASHRAE 90.1-2007. In an attempt to achieve the established energy-saving targets, the impact on building HVAC load and operating cost, building-envelope measurements, such as fenestration U-value, opaque wall U-value, and glass shading coefficient (SC) were studied. As shown in computer energy models, better façade insulation will reduce the HVAC load and related operational cost at a slightly higher initial cost. With the comprehensive consideration of initial cost, operational cost, energy savings, and building shape etc, the façade parameters outlined in Table 2.1 were finalized. Heating and Cooling Sources The height of the HVAC-serviced area in this project is 598 meters. If only one centralized water cooled chiller were used, then at least four heat exchangers would be needed to avoid overpressurizing the water system. Each heat exchanger will lead to a 1 C temperature difference Therefore, in order to maintain the temperature of the highest point at 7 C, to achieve dehumidification, the output water temperature of the chiller should be set at 3 C. This will result in significant reduction of efficiency of the chiller and cause huge energy loss. As a result, a separate chiller plant room was proposed for the hotel area. 能源设计 节能永远是绿色建筑的核心理念, 超高层建筑也不例外, 需要提供照明, 通风, 制冷, 供暖, 设备等大量消耗能源的系统 减少能源需求的起点是优化建筑的维护结构参数 项目团队通过对标准层能耗模拟的方式寻求最佳的维护结构设计 减少需求根据 LEED 能源与环境设计先锋奖 以及 绿色超高层建筑评价技术细则 的相关要求, 项目团队制定以下目标 与最新中国能源标准相比, 全年累计空调采暖和制冷负荷降低 3% 与最新中国能源标准相比, 全年暖通空调系统节能率 20% 与 ASHRAE 90.1-2007 标准相比, 全年能耗运行费用节省 16% 依据建筑可能达到的保温性能, 分别研究了透明幕墙的保温性能设计, 不透明幕墙的保温设计, 玻璃的遮阳系数对于建筑能耗和运行费用的影响 ; 计算机全年动态研究结果表明, 在工程范围内, 研究的三个指标随着保温性能的改善呈单项变化 综合考虑造价等因素, 本项目拟采用以下保温性能作为设计依据 ( 见表 2.1) 冷热源绿色设计本项目空调区域的高度为 598 米, 如果只是 26 Architecture, Systems and Environmental Design
Considering the division of property ownership and the measurement of needs, the offices at the lower levels of the tower and podium space are provided with their own dedicated water-cooled chiller plant rooms. Megatall buildings have a very high airconditioning demand at peak times. In order to balance cooling and heating demands, an ice storage system was proposed. Although the ice storage system will do little to reduce energy consumption, it will balance the electricity demand between daytime and nighttime, which will contribute to the preservation of the city s energy infrastructure and protect the environment, which had been encouraged by local policies. The peak cooling load for a typical summer day is 72,510 TRH (excluding the apartments). The ice storage system s anticipated capacity required is 21,760 TRH, which is 30% of the daily peak cooling load. Since most of the cooling requirement for the hotel will occur during the night, the ice storage system will be mainly used for the offices and podium at the bottom of the tower (see Figures 2.14 and 2.15 and Table 2.2). In order to avoid consuming additional electricity and/or gas, all of the HVAC heating load and domestic hot water load will come from civil waste steam. Renewable Energy Using solar energy was a major goal of the project. The tower s roof is not flat, so 1,500 square meters of solar panels were placed on the roof of the podium. The annual energy generated is expected to be 261,450 kwh, which will be used for powering the service equipment in the podium such as fans, cooling tower, etc. Types 类型 Performance Data 参数要求 Assembly Fenestration U-value 透明部分综合传热系数 Opaque wall U-value 不透明部分综合传热系数 < 2.0 w/m 2 /k < 0.6 w/m 2 /k < 0.3 Table 2.1. The consideration of energy-saving targets in the façade 表 2.1. 对于节能目标的考虑 Figure 2.14. Office Ice Storage 图 2.14. 办公部分冰蓄冷示意图 Glass SC 玻璃遮阳系数 Water Design Because of its lakeside setting, it is commonly though that Suzhou has a very rich water resource. In fact, much of Suzhou s water Figure 2.15. Podium Ice Storage 图 2.15. 商业部分冰蓄冷示意图 建筑 系统和环境设计 27
Office 办公 Podium 裙楼 Performance Data 参数要求 Regular System 常规系统 Ice Storage System 冰蓄冷系统 Peak-time chiller electricity Demand 冷机峰值用电需求 HVAC Summer Operation Cost 空调夏季运行费用 Chiller Plant Equipment additional Cost 制冷机房设备追加投资 Peak-time cooling electricity Demand 冷机峰值用电需求 HVAC Summer Operation Cost 空调夏季运行费用 1086 kw 1,978,000 RMB 0 2100 kw 2,678,000 0 Chiller Plant Equipment Cost 制冷机房设备追加投资 448 kw 1,006,000 RMB 6,000,000 RMB 1087 kw 1,508,000 7,000,000 RMB Table 2.2. Cooling demand at office and podium levels 表 2.2. 办公区及裙房层的制冷需求 comes from other cities and runs through Suzhou. The total water resource for the city is 10 billion cubic meters, or less than 2,000 cubic meters per capita. Seventy percent of its water is sourced from other provinces and cities, and the other 30% is from local rainwater. Therefore, if a drought occurs in the upstream area, Suzhou will have a lack of water. In addition, pollution of surface water means just under 50% of the water can be used for industrial and domestic purposes. Huge water demand will not only increase the operating costs and life-cycle costs of the building, but would also add pressure to municipal water supply and treatment facilities. On the contrary, buildings that use water efficiently can reduce maintenance costs, produce less sewage, lower sewage treatment costs and reduce the initial investment for the city water supply system. Therefore, water conservation is taken as an important design objective. Reducing Water Demand Water-saving products will be introduced to all water consuming points in the building. The preliminary design and benchmark comparison are listed in Table 2.3. Design for Greywater Megatall buildings use and discharge a significant amount of water daily. Due to the large number of apartments in this project, the water resources consumption is even more significant. However, the large amount of greywater brings more opportunities for water saving in this project through greywater reuse. 设计一个集中冷站, 那么需要四个板换作为压力分割, 否则整个系统的压力将超过常规设备的承受能力 每个板式换热器基本会带来 1 度的温度差, 为了保证最高处的温度在 7 度左右用于除湿, 那么冷冻机房的出水温度需要设计为 3 度, 这个会严重降低冷机的运行效率, 能源损失较为严重 所以酒店部分会单独设计一个冷冻机房 考虑到产权分割和计量需求, 位于建筑相对较低位置的塔楼办公和裙房将分别采用集各自的冷站提供空调冷源 超高层建筑的空调峰值需求较大, 为了平衡建筑的一天负荷情况, 削峰填谷, 本项目采用了冰蓄冷系统 蓄冷技术虽然从能源转换和利用本身来讲并不节约, 但是其对于昼夜电力峰谷差异的调节具有积极的作用, 能够满足城市能源结构调整和环境保护的宏观要求, 具有一定的政策性鼓励意义 本项目在夏季设计日空调的冷负荷 ( 公寓部分除外 ) 为 72,510 冷吨时, 预计采用的冰蓄冷容量为 21,760 冷吨时, 比例为 30% 由于酒店的大部分冷负荷均出现在夜间, 因此本项目的冰蓄冷系统服务于位于建筑底部的办公和裙房商场部分 ( 见图 2.14 2.15 及表 2.2) 整个建筑的空调热源和集中热水热源全部采用市政余热, 避免消耗额外的电力或者燃气 可再生能源利用项目的主要目标为高效的使用太阳能 本项目塔楼无屋顶, 因此布置了 1,500 平方米的太阳能发电板在裙房屋顶, 年发电量预计 261,450 kwh, 这些电会用于裙房屋顶的机电设备运转例如风机, 冷却塔等 水资源设计 苏州地区水多是一个表面现象, 实际情况是过境水多, 本地产水少 苏州全市水资源总量为 100 亿立方米, 人均占有量不足 2,000 立方米 且 70% 来自其他省市的过境水, 通过苏州本地降雨形成的水约为 30%, 如果上游地区干旱, 那么苏州将会缺水 ; 另外地表水污染情况较为严重, 能够用于生产和生活的水不到 50% 建筑水资源的大量消耗会严重增加建筑的使用成本和全生命周期成本, 同时也会增加市政管网的投资和压力 建筑的节约用水能够降低运行费用, 降低污水排放, 减少污水处理成本, 同时降低自来水系统的一次投资 本项目将节约用水作为一个重要的设计任务 减少需求所有部位的用水器具采用节水性的产品, 初步的设计参数和基准如下表 2.3 所示 再生水设计 28 Architecture, Systems and Environmental Design
Sanitary 类型 Water Closet 大便器 Urinal 小便器 Lavatory Faucet 卫生间洗手龙头 Shower 洗澡龙头 Kitchen Sink 茶水间厨房龙头 Office/Retail/Hotel Public Space 办公 / 商业 / 酒店公共区域 Proposed 3/6 L 1.9 L 3.8 L 7.6 L 9.4 L 设计参数 Benchmark 6 L 3.8 L 3.8 L 9.4 L 9.4 L 基准参数 Unit 单位 Apartment 公寓 Proposed 3/6L N/A 3.8L 9.5L 8.4L 设计参数 Benchmark 基准参数 Unit 单位 6 L N/A 8.4L 9.5L 8.4L Hotel Guest Room 酒店客房 Proposed 设计参数 Benchmark 基准参数 Unit 单位 3/6L N/A 3.8L 12 L N/A 6 L N/A 8.4L 9.5L N/A N/A Table 2.3. Preliminary design and benchmarks for water consumption levels 表 2.3. 初步设计及基准用水量水平 Renewable Sources of Water The project will collect the high-grade greywater from the hotel, apartment and small office / home office (SOHO) functions (see Table 2.4). Due to the strong wind force at the top of the building, rainwater is very difficult to collect. Also because of the small surface area, roof and façade rainwater collection systems were not considered. Due to the daylight demand at the basement level, a sunken plaza was designed. Rainwater from the north of the plaza is collected in the rainwater pond, and then treated by a mechanical filter to reach the standard of recycled water, and then finally mixed into the clean water reservoirs for re-use. However, the volume is minimal, and thus it is not normally considered in non-traditional water reuse calculations. Design for Reclaimed Water Treatment Process and System The greywater treatment system is designed to process 295 m³ /day at an average rate of about 24 m³/hour, running 12 hours a day. Considering the running efficiency, 205 m³/day of greywater can be treated. Therefore 74,825 m³ of greywater can be treated each year. The Scope of Reclaimed Water Re-use Landscape irrigation: about 134 m³ per year Road flushing: about 23,618 m³ per year Garage flushing: about 3,429 m³ per year Fountains: about 413 m³ per year Office and retail toilet flushing: about 48,062 m³ per year From the above, the calculated yearly water demand is about 75,656 m³, which can be matched by the greywater system. N/A 超高层建筑的日用水量和排水量均非常大, 针对本项目的大量公寓, 水资源的消耗更甚 同时, 大量优质杂排水也为本项目带来了更多的节水机会 为了更好地节约用水, 本项目设计了中水回收处理和回用系统 再生水的来源本项目拟回收酒店 公寓 公寓式办公的优质杂排水 ( 见表 2.4) 超高层建筑由于在高处风力较大, 雨水很难汇流被收集, 同时也因为超高层建筑的占地面积较小, 因此本项目未考虑屋顶和立面的雨水收集系统 由于采光需要, 本项目设计了下沉式广场 收集北侧下沉广场的雨水, 经过初期弃流, 收集到雨水池, 经过机械过滤等工艺处理到回用水的相应标准, 混入中水清水池回用 由于其水量较小, 在非传统水源的回用比例计算过程中不予考虑 再生水的处理工艺和系统设计整个中水处理系统的规模按照 295m 3 / 天, 设计平均处理速度为 24m 3 /h, 每天的运行时间为 12 小时, 考虑到运行效率, 本项目的日产水量按照 205m 3 / 天进行计算, 全年产水量为 74825 立方米 再生水回用范围 绿化灌溉, 约 134m 3 / 年 道路浇沙, 约 23,618m 3 / 年 地库冲洗, 约 3,429m 3 / 年 景观补水, 约 413m 3 / 年 办公及商业厕所冲洗, 约 48,062m 3 / 年 上述部位的年需水量约为 75,656m 3, 和中水处理系统匹配 非传统水源利用比例整个项目的年用水量约为 73,2513m 3,( 包含冷却塔补水 景观用水 道路冲洗用水 洗车用水 ) 本项目非传统水源的利用比例为 74,825 / 732,513 = 10.21% 地下室采光 建筑 系统和环境设计 29
Item 序号 Place 部位 Number 使用数量 Discharge Standard 原水排水量标准 Discharge Coefficient 排水量系数 Day 用水天数 Water volume per day 平均日原水量 Water volume per year 全年原水量 1 Guest Room 酒店客房 567 Bed/ 床 220L/D/B 床 0.58 365 71.9 26225 2 Hotel staff 酒店员工 281 70L/D/D 天 0.58 365 11.3 4135 3 Tour 会所观光 8 800L/D/D 天 0.58 365 3.7 1346 4 Apartment 公寓 1778 140 L/D/P 人 0.55 365 137.6 50207 SOHO 574 240 L/D/P 人 0.31 264 42.2 11129 5 office 公寓办公 6 Office 办公 3383 25L/D/P 人 0.31 264 25.9 6832 292.6 99874 Table 2.4. Estimated water consumption 表 2.4. 预计用水量 Proportion of Non-Traditional Water Use The total water consumption of this building (including cooling tower make-up, landscape use, road cleaning, car washing, indoor water, etc.) is about 732,513 m³ per year. This makes the nontraditional water ratio 74,825 / 732,513, or 10.21%. Basement Lighting Eighty percent of the information that people get from the outside world comes from natural light and optical radiation. Natural light has a positive effect a person s motivation and mood. Providing daylight to the underground space is not only beneficial to energy savings, but also improves conditions for occupants. Due to the enclosure of underground space, natural light can increase the natural communication between indoor and outdoor spaces, and reduce psychological ill effects. Natural lighting can also work as a reliable source of basement emergency lighting in the daytime. The introduction of three sunken plazas let daylight into the basement space, which covers up to 22% of the area of basement level 1. Site Wind Environment Design According to relevant studies, in order to avoid unpleasant incidents, such as strong wind at the pedestrian level, which may drive objects into the façade or inhibit walking, the wind speed should be less than 5m/s within the pedestrian zone around the building, and particularly between the ground and 1.5 meters above grade to ensure comfort while conducting normal activities. Besides, poor ventilation will severely hinder the flow of wind, which may even create stagnant pockets and vortices in some places. These phenomena are not conducive to the dissipation of outdoor heat and pollutants, so they should be avoided as much as possible. The design of this project resulted from seeking the best solution for the outdoor wind environment. Simulation results showed that under the dominant wind direction, the wind speed is less than 5m/s within the zone of 1.5 meter high above the ground in the pedestrian 人从外界获得的信息约有 80% 都来自光和光辐射引起的人的视觉 自然光对人的灵敏度 活力指数和心情有正面作用 地下空间的天然采光不仅有利于照明节能, 而且充足的天然光还有利于改善地下空间卫生环境 由于地下空间的封闭性, 天然采光可以增加室内外的自然信息交流, 减少人们的压抑心理等 ; 同时, 天然采光也可以作为日间地下空间应急照明的可靠光源 本项目准备设计三个下沉式广场, 有效地下室采光面积达到地下室一层面积的 22% 场地风环境设计为避免建筑单体设计和群体布局不当, 而有可能导致行人举步维艰或强风卷刮物体撞碎玻璃等事故, 相关研究表明, 建筑物周围人行区 1.5m 高处风速宜低于 5m/s, 以保证人们在室外的正常活动 此外通风不畅还会严重地阻碍风的流动, 在某些区域形成无风区和涡旋区, 不利于室外散热和污染物消散, 因此应尽量避免 本项目通过有效的体型设计, 最大限度的改善室外的风环境 根据如下模拟结果显示 : 各季节主导风向下, 建筑室外人行区在距离地面 1.5 米高度处的风速小于 5.0m/s, 室外风速放大系数小于 2, 建筑周围人行区 30 Architecture, Systems and Environmental Design
Figure 2.16. Public plaza below the mall will attract and entertain visitors from near and far (Source: Gensler) 图 2.16. 购物中心下方的公共广场将吸引远近的游客前来休闲娱乐 ( 来源 :Gensler) area around the building. Also, the outdoor wind velocity amplification coefficient is less than 2 and the wind environment is within the range of comfort requirements. According to the simulation analysis of the outdoor wind environment, the project meets both the new and old editions of the GB/T50378 green building evaluation standard, as well standards for highrise green buildings. Conclusion In recent years, scholarship and technology around green buildings have developed rapidly. High-rise green buildings have their own distinctive features. Through the study on this project, the following green building elements are identified as crucial for megatall buildings: Water resource saving HVAC cooling sources Combined with other green building design concepts, this project aims to achieve LEED CS 2009 Gold certification and CHINA Green Label Three Stars. 风环境在舒适度要求的范围之内 ; 根据室外风环境的模拟分析, 本项目满足 GB/T50378 绿色建筑评价标准 新旧版和 绿色超高层建筑评价技术细则 的要求 结语 关于绿色建筑的话题和技术近些年发展迅速, 超高层建筑有着其自身鲜明的特点 通过本项目的研究, 以下绿色建筑元素对于超高层建筑更有意义 节约水资源 空调冷源配合其他绿色建筑的设计理念, 本项目的绿色建筑目标为国际上通用 LEED CS 2009 黄金级和中国绿色建筑标准三星级 References ( 参考书目 ): GB50378 Green Building Evaluation Standard Super High-rise Green Building Evaluation Details LEED Core & Shell 2009 建筑 系统和环境设计 31