基于全生命周期理论的建筑能耗问题研究

本文以全生命周期理论为基础.分析了我国宏观建筑能耗问题,得出了各个生命周期阶段节能的重点.通过对建筑全生命周期能耗进行分析,可以看出:建筑材料准备阶段的能耗和建筑运行能耗为建筑能耗的重要部分.减少建筑运行能耗是建筑节能的关键,减少建筑材料能耗同样具有重要的作用.     

Eco-Bat: A design tool for assessing environmental impacts of buildings and equipment

This paper presents the features of Eco-Bat, a computer program developed to assess the environmental impacts of buildings, including construction materials and energy consumed, during its life cycle. The methodology used to evaluate environmental impacts based on a life cycle assessment (LCA) approach, compatible with ISO 14040 standards, is detailed. The data are mainly extracted from an environmental impacts database, Ecoinvent, which contains values for the manufacturing and elimination of numerous materials as well as other processes. Two applications are presented to illustrate the possibilities offered by Eco-Bat. The first one is a comparison of different variants of building facades. The second example shows the analysis of a whole building including its energy consumption.     

Life-cycle assessment of post-disaster temporary housing

The estimation of energy consumption and related CO₂ emissions from buildings is increasingly important in life-cycle assessment (LCA) studies that have been applied in the design of more energy-efficient building construction systems and materials. This study undertakes a life-cycle energy analysis (LCEA) and life-cycle CO₂ emissions analysis (LCCO₂A) of two common types of post-disaster temporary houses constructed in Turkey. The proposed model includes building construction, operation and demolition phases to estimate total energy use and CO₂ emissions over 15- and 25-year lifespans for container houses (CH) and prefabricated houses (PH) respectively. Energy efficiency and emission parameters are defined per?m² and on a per capita basis. It is found that the operation phase is dominant in both PH and CH and contributes 86–88% of the primary energy requirements and 95–96% of CO₂ emissions. The embodied energy (EE) of the constructions accounts for 12–14% of the overall life-cycle energy consumption. The results show that life-cycle energy and emissions intensity in CH are higher than those for PH. However, this pattern is reversed when energy requirements are expressed on a per capita basis.     

Energy and environmental comparison of three variants of a family house during its whole life span

The aim of this study is to analyse and compare three variants of a family house in order to evaluate the total environmental impacts produced during the whole building life cycle. The first variant corresponds to the standard in force in Switzerland, the second alternative to the requirements of a quality control label for houses with low energy consumption and the third case is a very low energy consumption building. The three variants have the same architectural aspect but different insulation thicknesses and types, different energy production systems and the use of different renewable energies. The calculation of the environmental impacts is carried out by means of a life cycle analysis, which includes not only the impact related to the energy consumption during the occupancy stage, but also the materials manufacture, transport, replacement and elimination at the end of the building lifetime. The results are expressed with the Swiss and the UCTE (Union for the Co-ordination of Transmission of Electricity) electricity mix to analyse how they influence the building impact.     

筑屋于木——木质结构建筑的综合环境足迹分析

建筑业对资源、能源的巨大消耗,造成的严重环境污染等。该文用生命周期分析方法,对木质结构建筑在全生命周期内（包括建材物化阶段和建筑运行阶段）的能耗进行理论分析,从而确定选择合适的建筑材料和形式对环境的综合影响,为木结构建筑的发展提供一些思路。     

A life-cycle energy analysis of building materials in the Negev desert

Environmental quality has become increasingly affected by the built environment—as ultimately, buildings are responsible for the bulk of energy consumption and resultant atmospheric emissions in many countries. In recognizing this trend, research into building energy-efficiency has focused mainly on the energy required for a building's ongoing use, while the energy “embodied” in its production is often overlooked. Such an approach has led in recent years to strategies which improve a building's thermal performance, but which rely on high embodied-energy (EE) materials and products. Although assessment methods and databases have developed in recent years, the actual EE intensity for a given material may be highly dependent on local technologies and transportation distances. The objective of this study is to identify building materials which may optimize a building's energy requirements over its entire life cycle, by analyzing both embodied and operational energy consumption in a climatically responsive building in the Negev desert region of southern Israel—comparing its actual material composition with a number of possible alternatives. It was found that the embodied energy of the building accounts for some 60% of the overall life-cycle energy consumption, which could be reduced significantly by using “alternative” wall infill materials. The cumulative energy saved over a 50-year life cycle by this material substitution is on the order of 20%. While the studied wall systems (mass, insulation and finish materials) represent a significant portion of the initial EE of the building, the concrete structure (columns, beams, floor and ceiling slabs) on average constitutes about 50% of the building's pre-use phase energy.     

绿色居住建筑全生命周期碳排放研究

建筑领域碳排放占全社会总能耗的1/3,这仅仅是建筑运行使用过程,若考虑建筑全生命周期,比例将会更高。在现行的绿色建筑评价标准引导下,绿色建筑是否比普通建筑全生命周期更低碳,目前相关研究甚少。本项研究基于LCA理论,在总结前人研究基础上,明确绿色建筑全生命周期碳排放计算方法,并以天津生态城75栋绿色居住建筑为样本,计算并比较了不同星级绿色居住建筑全生命周期碳排放水平。结果表明,单位建筑面积年碳排放量为43-64kg CO2/m2·a,且碳排放水平与绿色建筑星级无明显关系。本项研究为建立天津地区建筑全生命周期碳排放清单数据库和评价体系提供支撑。     

建筑材料全寿命期CO2 排放量计算方法

建筑材料CO2 减排是我国整体CO2 减量计划的重要方面,建筑材料CO2 排放量的计算是发展低碳建材、推进建筑节能减排的前提和基础,为此需要确立建筑材料CO2 排放量的计算方法。通过CO2 排放活动分析,从全寿命期和CO2 排放源角度,确定了建筑材料CO2 排放构成;并对六种建筑材料CO2 排放量的计算方法进行了比较分析,选择碳排放系数法作为计算我国建筑材料CO2 排放量的方法;构建了建筑材料全寿命期CO2 排放三阶段计算模型,并提出了建筑材料生产、运输以及处置阶段CO2 排放因子的确定方法。应用实例显示,该方法可较方便地测算出建筑材料全寿命期CO2 排放量。     

基于BIM的小型节能建筑生命周期环境影响和成本分析

被动式超低能耗建筑通过被动式设计策略、高性能的围护结构和高效的设备体系降低其使用阶段能耗。零能耗建筑在此基础上,采用太阳能光伏发电等可再生能源系统,进一步降低不可再生能源消耗。这两类节能建筑的材料和设备系统的隐含能耗、环境影响和成本通常高于一般建筑,同时对构件的后期维护和替换提出了更高的要求。因此,有必要从生命周期的范畴分析其环境和经济效益。建筑信息模型（BIM）能够为建筑项目的建造、运行和拆解等阶段提供多专业共享的数据平台。本文基于BIM,通过LCA和LCC方法对一座小型住宅建筑在不同节能目标情景下的生命周期全球变暖潜势值（GWP）、一次能耗（PE）和成本（LCC）进行分析和比较。结果表明,零能耗乃至正能源建筑在降低一次能耗和GWP方面具有明显优势,被动式超低能耗建筑也具有良好的环境效益。在经济效益方面,由于住宅建筑能源价格较低,如果按近年的价格指数计算,零能耗建筑和被动式超低能耗建筑的初建成本和后期构件替换成本增量将抵消其使用阶段节约的能耗成本,因此生命周期成本高于普通节能建筑。如果未来50年能源价格涨幅超过建筑安装价格涨幅,那么零能耗建筑在生命周期成本方面将具有优势。     

建设项目能耗的经济年限研究

降低建筑能耗是近年来我国节能减排的一个重点,本文基于建设项目全生命周期能耗,探讨建设项目能耗经济年限的涵义,进而讨论它的计算方法,并以南京某项目的一栋18层楼的单体为例,计算该建设项目能耗的经济年限,分析并得出结论。     

Life cycle assessment in buildings: State-of-the-art and simplified LCA methodology as a complement for building certification

The paper presents the state-of-the-art regarding the application of life cycle assessment (LCA) in the building sector, providing a list of existing tools, drivers and barriers, potential users and purposes of LCA studies in this sector. It also proposes a simplified LCA methodology and applies this to a case study focused on Spain. The thermal simulation tools considered in the Spanish building energy certification standards are analysed and complemented with a simplified LCA methodology for evaluating the impact of certain improvements to the building design. The simplified approach proposed allows global comparisons between the embodied energy and emissions of the building materials and the energy consumption and associated emissions at the use stage.The results reveal that embodied energy can represent more than 30% of the primary energy requirement during the life span of a single house of 222 m² with a garage for one car. The contribution of the building materials decreases if the house does not include a parking area, since this increases the heated surface percentage. Usually the top cause of energy consumption in residential building is heating, but the second is the building materials, which can represent more than 60% of the heating consumption.     

建筑门窗绿色建材产品认证技术要点分析

在建筑领域碳排放中,建材生产和建筑运行中的碳排放占比较大。建筑门窗绿色建材产品鼓励采用先进技术工艺,降低生产过程的废料产出,加大包装材料可循环利用,提高产品使用周期及核心设计指标要求,保证品质的同时降低资源消耗。评价标准能源属性指标中气密性能、传热系数、太阳得热系数按照不同星级和区域进行划分,有利于降低建筑运行能耗。本文对建筑门窗产品认证评价过程中的技术要点进行分析,有助于指导企业自评价的准确性,保证门窗绿色建材产品评价指标落到实处,同时提出在评价过程增加产品碳足迹和单位产品综合能耗分析,有助于对绿色建材产品减碳效果进行评价。     

建筑给水管生命周期能耗分析方法及应用

建筑给水管材的选用对于建筑节能具有十分重要的现实意义。传统的建筑给水系统设计中管材的选用主要考虑其使用性能和一次性成本,忽视了不同的管材在整个生命周期过程中的能耗差异。本文首先运用生命周期评价方法有效地比较分析了建筑给水管材在其生命周期各个阶段的能耗,为建筑给水节能设计提供了一种全面有效的方法。而后从工程实际出发选择了2种常见的建筑给水管材并进行了生命周期能耗分析比较,得出在实现同等供水功能的前提下,镀锌钢管比硬聚氯乙烯给水管材生命周期能耗大。     

超高层建筑结构优化过程中的环境成本计算

近年来中国大陆掀起了超高层建筑的兴建热潮。超高层建筑体量巨大,其碳排放和能源消耗对环境有显著影响。在评估和优化超高层建筑的全生命周期环境成本时,提出了一个全新的全生命周期模型。新模型有两大特征：首先,同时考虑了建筑材料的空间分布与时间特征;其次,把单尺度生命周期概念拓展到多尺度生命周期概念,以从更多角度来研究碳排放情况。建立了一个基准超高层建筑模型来阐释对新模型的应用。根据初步研究结果,应用新方法可以选择出更优化的结构设计方法,以最大程度减少碳排放量。     

Life-cycle energy analysis of buildings: a case study

Energy use is a widely used measure of the environmental impact of buildings. Recent studies have highlighted the importance of both the operational and embodied energy attributable to buildings over their lifetime. The method of assessing lifetime building energy is known as life-cycle energy analysis. With Kyoto target obligations necessitating the quantification of greenhouse gas emissions at the national level, it seems increasingly probable that analyses of this kind will increase in use. If conducted in primary energy terms, such analyses directly reflect greenhouse gas emissions, except for a few processes which involve significant non-energy related emissions such as cement manufacture. A Life-Cycle Assessment would include these issues, as well as other environmental parameters, though probably with a corresponding decrease in system boundary completeness. This paper briefly explains some of the theoretical issues associated with life-cycle energy analysis and then uses an Australian based case study to demonstrate its use in evaluating alternative design strategies for an energy efficient residential building. For example, it was found that the addition of higher levels of insulation in Australia paid back its initial embodied energy in life-cycle energy terms in around 12 years. However, the saving represented less than 6% of the total embodied energy and operational energy of the building over a 100-year life cycle. This indicates that there may be other strategies worth pursuing before additional insulation. Energy efficiency and other environmental strategies should be prioritized on a life-cycle basis. La consommation d'energie est un parametre tres utilise lorsque l'on veut mesurer l'impact des batiments sur l'environnement. Des etudes conduites recemment ont mis en lumiere l'importance de l'energie operationnelle et celle de l'energie intrinseque degagees par les batiments pendant leur duree de vie. L'analyse energetique des batiments pendant leur cycle de vie est une methode d'evaluation de l'energie d'un batiment pendant sa duree de vie. Pour respecter les objectifs de la Conference de Kyoto, il faut quantifier les emissions de gaz de serre au niveau national; il semble donc de plus en plus probable que la pratique de ces analyses va aller en augmentant. Si elles portent sur l'energie primaire, ces analyses rendront parfaitement compte des emissions de gaz a effets de serre, sauf pour quelques procedes industriels, comme la fabrication du ciment, ou les emissions de ces gaz ne sont pas liees a l'energie. Toute evaluation du cycle de vie doit tenir compte de ces questions mais aussi d'autres parametres environnementaux, mais avec, sans doute, une moindre nettete des limites des systemes. Le presente communication expose brievement quelques uns des problemes theoriques lies aux analyses energetiques sur le cycle de vie et s'appuie sur une etude de cas australienne pour demontrer son utilite a evaluer d'autres strategies de conception de batiments a usage d'habitation a faible consommation d'energie. On a constate, par exemple, qu'en Australie le fait d'ajouter des niveaux d'isolation remboursait en 12 ans environ l'energie intrinseque initiale en terme d'energie sur le cycle de vie. Toutefois, les economies representaient moins de 6% de l'energie intrinseque totale et de l'energie operationnelle du batiment sur un cycle de vie de 100 ans. Cela veut dire qu'il serait peut etre interessant d'envisager d'autres strategies avant d'augmenter l'isolation. On devrait donner priorite a l'efficacite energetique et a d'autres strategies environnementales sur la base du cycle de vie.     

Life cycle primary energy use and carbon emission of an eight-storey wood-framed apartment building

In this study the life cycle primary energy use and carbon dioxide (CO₂) emission of an eight-storey wood-framed apartment building are analyzed. All life cycle phases are included, including acquisition and processing of materials, on-site construction, building operation, demolition and materials disposal. The calculated primary energy use includes the entire energy system chains, and carbon flows are tracked including fossil fuel emissions, process emissions, carbon stocks in building materials, and avoided fossil emissions due to biofuel substitution. The results show that building operation uses the largest share of life cycle energy use, becoming increasingly dominant as the life span of the building increases. The type of heating system strongly influences the primary energy use and CO₂ emission; a biomass-based system with cogeneration of district heat and electricity achieves low primary energy use and very low CO₂ emissions. Using biomass residues from the wood products chain to substitute for fossil fuels significantly reduces net CO₂ emission. Excluding household tap water and electricity, a negative life cycle net CO₂ emission can be achieved due to the wood-based construction materials and biomass-based energy supply system. This study shows the importance of using a life cycle perspective when evaluating primary energy and climatic impacts of buildings.     

Comparison of environmental impacts of two residential heating systems

This paper presents a comparison of environmental impacts of two residential heating systems, a hot water heating (HWH) system with mechanical ventilation and a forced air heating (FAH) system. These two systems are designed for a house recently built near Montreal, Canada. The comparison is made with respect to the life-cycle energy use, the life-cycle greenhouse gas (GHG) emissions, the expanded cumulative exergy consumption (ECExC), the energy and exergy efficiencies, and the life-cycle cost. The results indicate that the heating systems cause marginal impacts compared with the entire house in the pre-operating phase. In the operating phase, on the other hand, they cause significant environmental impacts. The HWH systems with a heat recovery ventilator (HRV) using either electricity or natural gas have the lowest life-cycle energy use and lowest ECExC. The HWH and FAH systems using electricity as energy source have the lowest GHG emissions. Finally, the FAH systems have, on the average, a lower life-cycle cost than the HWH systems.     

A comparative life cycle assessment of a transparent composite façade system and a glass curtain wall system

High performance glass such as low-e coated or heat reflective glass offers better thermal performance, preventing undesired heat loss or gain during a building operation phase. However, these coatings may not be as effective in certain climate zones and create glare problems for adjacent buildings. A transparent composite façade system (TCFS) was newly configured to provide a sustainable alternative to a high performance glass wall in that the biofiber composite core acts as a shading device while the airspace between the polymer skins provides adequate insulation. A comparative life cycle assessment (LCA) method was selected as a sustainability measuring tool to compare the environmental impacts of a TCFS with a glass curtain wall system (GCWS). In this paper, the environmental performance of a façade system is characterized by the energy consumption and CO₂ emissions through all stages of the life cycle. Comparative LCA results show that the total life cycle energy of the TCFS is estimated to be 93% of that of the uncoated GCWS, and the total emissions of kg CO₂ equivalent for the TCFS is determined to be 89% of the uncoated GCWS. The use phase for both the TCFS and GCWS plays a dominant role in reducing environmental impacts while the impact associated with transportation and the end-of-life management is estimated to be insignificant in this study. The life cycle inventory data and analysis results provided in this paper are expected to assist designers with a better understanding of building material selection and system improvement from the whole life cycle perspectives.     

基于全生命周期的建筑节能研究

目前建筑节能的主要关注点是建筑使用阶段运行能耗的节能,而建筑能耗却贯穿于建筑的各个阶段,因此应从生命周期的角度对建筑节能进行研究,这样可以对建材准备、建造、使用等建筑的各个阶段的能耗进行控制,从而达到建筑全生命周期能耗最低,实现真正的节能.首先运用生命周期理论构建出建筑全生命周期能耗的计算模型,在此基础上对我国建筑全生...