Integrated assessment method for building life cycle environmental and economic performance

Life cycle assessment (LCA) is a powerful tool to identify a building’s environmental impact throughout its life cycle. However, LCA does have limits in practice because it does not consider the economic aspect of project implementation. In order to promote LCA application, a more comprehensive evaluation of building life cycle environmental and economic performance must be performed. To address these issues, we propose life cycle green cost assessment (LCGCA), a method that combines LCA with life cycle costing (LCC). In LCGCA the building’s environmental loads are converted to environmental costs based on the trading price of CO₂ certified emission reductions (CERs). These environmental costs are then included into the building life cycle cost. Subsequently an evaluation index of green net present value (GNPV) for LCGCA can be obtained. A governmental office building in Beijing was studied using LCGCA. Several design options were compared and the sensitivity of the CER price was analyzed. The research also shows that conclusions reached by LCGCA may be different from those of traditional LCC, which does not include environmental costs. The application of LCGCA needs the support of environmental policies. A sound environmental tax mechanism is expected to be established in China soon, which will enable LCGCA to be a useful tool to guide sustainable building design efficiently.     

Modelling building stock geometry for energy,emission and mass calculations

The effect of energy efficiency measures is generally evaluated for one or only a few houses. While the energy and environmental optimization of a particular building design is crucial, this cannot easily draw generic conclusions for future building designs. A method is presented for considering the effect of building geometry in simplified energy and life cycle assessment studies. Based on architectural and functional considerations, realistic ranges were determined for the parameters describing the geometry of ‘technically feasible’ buildings and their relationships. These parameters include floor area, the number of storeys, the perimeter-to-floor area ratio, the ratio of the building envelope adjoining neighbouring heated buildings, the window ratio and frame factor, the density of partition walls, and the roof slope. An algorithm is developed for the random generation of a large building sample based on the realistic ranges of these geometric parameters. By analysing the results, it is possible to calculate the expected value, standard deviation and confidence interval of the sample. The application of the method is shown in an example. The cumulative non-renewable energy demand is calculated for the whole life cycle and for different building types.

On évalue généralement l'effet des mesures de l'efficacité énergétique sur une ou seulement quelques habitations. Alors que l'optimisation énergétique et environnementale d'un modèle de bâtiment particulier est essentielle, elle ne permet pas de tirer facilement des conclusions génériques pour les futurs concepts de bâtiments. Cet article présente une méthode qui permet de prendre en considération l'effet de la géométrie d'un bâtiment dans des études d'évaluation simplifiées de l'énergie et du cycle de vie. En s'appuyant sur des considérations architecturales et fonctionnelles, on a défini des plages réalistes pour les paramètres décrivant la géométrie de bâtiments « réalisables sur le plan technique » et leurs relations. Ces paramètres incluent la surface au sol, le nombre de niveaux, le ratio entre le périmètre et la surface au sol, le ratio de l'enveloppe de bâtiments chauffés se trouvant à proximité, le ratio des fenêtres et le facteur de châssis, la densité des cloisons et la pente du toit. Un algorithme a été calculé pour la génération d'un grand échantillon aléatoire de bâtiments basé sur des plages réalistes de ces paramètres géométriques. En analysant les résultats, on peut calculer les valeurs escomptées, les écarts standard et l'intervalle de confiance de l'échantillon. L'application de cette méthode est décrite au moyen d'un exemple. La demande cumulée en énergie non renouvelable est calculée pour l'ensemble du cycle de vie et pour différents types de bâtiments.

Mots clés: géométrie des bâtiments, morphologie des bâtiments, parc bâti, efficacité énergétique, évaluation du cycle de vie, bâtiments résidentiels, Hongrie     

Embodied energy and cost of building materials: correlation analysis

The US building sector consumes 48% of the nation’s annual energy as operating and embodied energy. Calculating embodied energy is difficult, complex and more resource-consuming than calculating operating energy due to a lack of complete, accurate and specific embodied energy data. One commonly used method to calculate embodied energy is input–output-based (IO) analysis, which utilizes economic data. The use of economic data indicates some relationship between embodied energy and cost. Some studies have investigated whether the embodied energy of a building can be predicted from its cost. These studies analyzed the relationship of the cost and embodied energy of a building and found a strong, positive correlation. However, when analyzed at the material level, the correlation weakened. This paper develops an improved input–output-based hybrid (IOH) model to calculate the complete, accurate and material-specific embodied energy of 21 commonly used building materials. After calculating and evaluating the embodied energy, the correlation of the embodied energy and cost of materials was analyzed. The results demonstrate a very strong and positive correlation between embodied energy and cost. In conclusion, more research may be required to predict embodied energy from cost data.     

玻璃幕墙节能技术及性能评价研究

根据现代节能意识的需要,围绕玻璃幕墙节能技术,简单介绍了低辐射玻璃、中空玻璃和热反射玻璃等几种主要的节能玻璃类型,并通过模型对比试验对其节能状况进行了具体分析;利用生命周期评价法对玻璃幕墙的能耗进行了分析研究.     

Macroeconomic effects of energetic building retrofit: input-output sensitivity analyses

Energy efficiency measures in buildings are essential for climate protection, but are not always recognized by the investor in common profitability calculations. To provide a quantitative scientific base for policymakers, the aim is to identify and quantify the impact of these measures on Germany’s economy with a static open input-output model. Moreover, this investigation analyses how much the chosen base year affects the calculated macroeconomic impact, to obtain a clearer view of involved dynamics. The energy efficiency measures in buildings and their impact on energy demand and investments were simulated in the bottom-up building model INVERT/EE-Lab up to 2020. The methodological addition of this research is to identify and map the resulting impulses to the according macroeconomic sectors. Based on this stimulus a static input-output analysis is conducted using a range of base years. The results show that efficiency measures in buildings have a significant positive effect on macroeconomic key figures. The magnitude of the calculated impact depends on chosen base year data and varies for value added and employment. As a conclusion, the macroeconomic impact constitutes a co-benefit supporting the economic attractiveness of energy efficiency. However, studies based on a single base year dataset like many computable general equilibrium models may need to reflect the errors caused by that choice.     

浙江省新农村住宅生命周期的能耗分析与评价研究

以生命周期评价法为基本的理论方法,将新农村住宅建筑能耗整个的生命周期划分为建筑材料的生产、建材的运输、建筑的施工、建筑的运行维护、建筑的拆除及废物处理5个阶段,建立农村住宅建筑能耗生命周期评价模型。以浙江省新农村典型住宅为研究对象,对其各阶段的建筑能耗进行计算及评价研究,表明其在农宅运行维护及更新阶段所消耗的能耗占总能耗的62%。因此,对此阶段的能耗进行控制有很大的节能减排意义。     

Models for describing the thermal characteristics of building components

Outdoor testing of buildings and building components under real weather conditions provides useful information about their dynamic performance. Such knowledge is needed to properly characterize the heat transfer dynamics and provides useful information for implementing energy saving strategies, for example. For the analysis of these tests, dynamic analysis models and methods are required. However, a wide variety of models and methods exists, and the problem of choosing the most appropriate approach for each particular case is a non-trivial and interdisciplinary task. Knowledge of a large family of these approaches may therefore be very useful for selecting a suitable approach for each particular case.     

公共建筑能效指标及评价方法现状分析

分析现行公共建筑能效指标及评价方法,按其对建筑用能效率的分析深度划分为全楼宇层面和系统层面,又将评估全楼宇能效的指标按照数据来源分为基于统计数据和基于模拟数据两大来源,而系统层面主要是针对暖通空调系统和照明动力系统的评价。随机选取上海4栋大型公建的实际数据来测评全楼宇能效定额评估法,结果显示其并不能理想地为挖掘节能潜力提供指导。如今国内公建能效评估体系较为不统一,应从各地区能效标准逐步修改、扩展,建立完善的评估体系。     

Identification of the main thermal characteristics of building components using MATLAB

This paper presents the application of the IDENT Graphical User Interface of MATLAB to estimate the thermal properties of building components from outdoor dynamic testing, imposing appropriate physical constraints and assuming linear and time invariant parametric models. The theory is briefly described to provide the background for a first understanding of the models used. The relationship between commonly used RC-network models and the parametric models proposed is presented. The analysis is generalised for different possibilities in the assignment of inputs and outputs and even multiple output. Step by step guidance illustrated by an example is included. Results obtained using the different possibilities in selecting inputs and outputs are reported.     

The impact of indoor thermal conditions,system controls and building types on the building energy demand

It is possible to evaluate the energy demand as well as the parameters related to indoor thermal comfort through building energy simulation tools. Since energy demand for heating and cooling is directly affected by the required level of thermal comfort, the investigation of the mutual relationship between thermal comfort and energy demand (and therefore operating costs) is of the foremost importance both to define the benchmarks for energy service contracts and to calibrate the energy labelling according to European Directive 2002/92/CE. The connection between indoor thermal comfort conditions and energy demand for both heating and cooling has been analyzed in this work with reference to a set of validation tests (office buildings) derived from a European draft standard. Once a range of required acceptable indoor operative temperatures had been fixed in accordance with Fanger's theory (e.g. −0.5 < PMV < −0.5), the effective hourly comfort conditions and the energy consumptions were estimated through dynamic simulations. The same approach was then used to quantify the energy demand when the range of acceptable indoor operative temperatures was fixed in accordance with de Dear's adaptive comfort theory.     

生命周期评价理论及在建筑领域中的应用综述

生命周期评价通过对建筑产品从原材料挖掘到报废拆除整个生命期的分析,为全面衡量建筑的可持续能力提供了工具。在介绍生命周期评价概念和理论框架的基础上,对生命周期评价三种主要模型（过程生命周期评价模型、投入-产出生命周期评价模型、混合生命周期评价模型）的内容与特点进行了总结。针对目前国内外研究现状,回顾了生命周期评价在建筑材料与部品和整体建筑产品的应用,对生命周期评价在建筑领域中的发展给予展望。研究深入了当前对于生命期评价理论的认识与了解,指明了全生命周期评价模型在建筑可持续能力评估方面的优点与不足,推动了全生命周期评价理论在我国的丰富与发展     

夏热冬冷地区不同围护结构保温层厚度优化

采用全生命周期成本分析方法,结合度日数和现值系数,得出了保温层经济厚度优化模型,并对武汉地区典型外墙结构的保温层厚度优化和经济回收期进行分析.结果表明,采用简化外墙构造计算得到的保温层经济厚度,由厚到薄依次为:无机保温砂浆、EPS保温板、PU保温板,即保温材料的导热系数越小,保温层经济厚度越薄.另外,外墙保温虽然增加了初始费用,但减少了能耗费用,且能够在2～5年内收回成本,相比于保温材料20年的使用寿命,具有较好的经济效益.     

绿色奥运建筑评估体系围护结构节能评估研究及指标确定

综合分析了目前建筑围护结构节能设计标准的研究现状。研究并建立了绿色奥运建筑评估体系围护结构节能评估方法，对不同类型建筑根据其建筑本身及使用特点采用不同的评估方法，通过模拟计算确定了住宅建筑、商业建筑及体育场馆建筑的具体评估指标。     

新加坡绿色建筑标志及其评估标准

新加坡Green Mark评估体系虽设立年限较短,但由于其操作性强、标准明确、有效合理,得到了普遍的认可,成为促进绿色建筑发展的重要动力.主要介绍了新加坡Green Mark标准及指标设置,对指标的特点进行了分析.对能源效率、节水、环境保护、环境管理实践、室内环境质量及其他绿色特征等主要指标进行了说明,简单介绍了Green Mark的评估认证过程.     

Assessment of building cooling energy need through a quasi-steady state model: Simplified correlation for gain-loss mismatch

The objective of this work is to implement a simplified calculation procedure for building net energy need, based on a quasi-steady state model and on a monthly data set. In particular, it is intended to supply a formulation of the dynamic parameters and to adapt them to Italian climatic, typological, constructive and user data. The method was validated by determining the numerical correlations of the gain/loss utilization factor, through a comparison with a detailed building energy simulation software (EnergyPlus). The simulation was run on some test rooms defined by CEN (European Committee for Standardization) and on some real buildings that are representative of the Italian building stock, assuming weather data from different Italian locations (Torino, Roma, Palermo). The work shows that the accuracy of results is greatly affected by nonlinearities in the determination of the heat transfer and that the dynamic parameters are sensitive to some building features which are not taken into account in the CEN correlations.     

建筑生命周期评价工具的现状分析

建筑业是我国的支柱产业,对环境也造成了深刻的影响。对建筑物进行生命周期评价是促进建筑业可持续发展的重要手段。到目前为止,世界范围内已经开发出了一些建筑物生命周期评价的软件工具,它们都是针对各自的国家开发出来的,不适用于所有国家。我国在建筑业生命周期评价的研究也已开始,但总的说来还很不深入。     

Preparation and characterization of fatty acid ester/building material composites for thermal energy storage in buildings

In this study, fatty acid ester/building material composites as novel form-stable phase change materials (PCMs) were prepared by absorbing liquid fatty acid esters into porous network of conventional building materials. In the composite erythritol tetrapalmitate (ETP) and erythritol tetrastearate (ETS) esters were used as PCM for thermal energy storage, and cement and gypsum used as supporting material. The composite PCMs were characterized using scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis technique. The SEM results showed that the esters were confined in the porous network of the cement and gypsum. Thermal properties and thermal stabilities of the composite PCMs were determined by using differential scanning calorimetry (DSC) and thermal gravimetric (TG) analysis techniques. DSC results showed that the melting temperatures and the latent heats of the prepared composite PCMs were in range of 21.6-32.3 °C and 35.9-43.3 J/g, respectively. TG analysis indicated that the composite PCMs had good thermal stability. The thermal cycling test including 1000 heating and cooling process was conducted to determine the thermal reliability of the composite PCMs and the test results revealed that the composite PCMs have good thermal reliability and chemical stability.     

建筑物使用寿命的管理亟待法制化

建筑物使用寿命在设计上规定为５０年,而实际的使用寿命与建筑物的设计、施工、材料、使用情况等因素有关。建筑物的使用寿命到期后,若不采取拆除、改造或改变用途等相应措施,将会给建筑物的使用带来安全上的隐患。笔者建议,应为建筑物规定使用寿命的期限,作为有关部门实施建筑物使用寿命管理的法律依据     

Effects of thermal activated building systems in schools on thermal comfort in winter

There is a growing attention for the Indoor Air Quality problems in schools, but there is far less attention for the thermal comfort aspects within schools. A literature review is done to clear the effects of thermal quality in schools on the learning performance of the students: it clearly shows that thermal environment is like IAQ of great influence to the students' performance. As many studies focus on the ventilation aspects we focus more on the thermal comfort of the schools through measurements and questioners held in 14 schools equipped with different types of ventilation and heating systems.