我国广义建筑能耗状况的分析与思考

对广义建筑能耗的组成进行分析,并从运行能耗、建材能耗与间接能耗三方面对我国建筑能耗状况进行分析。结果表明,我国广义建筑能耗与全国总能耗呈现很强的线性相关性,广义建筑能耗与全国总能耗的比例约为45.5%。在广义建筑能耗中,运行能耗、建材能耗与间接能耗约占全国总能耗的20%、15%和10.5%,减少建筑运行能耗是建筑节能的关键,但减少建筑材料能耗具有同样重要的意义。     

建筑节能相变材料应用研究现状及发展

相变材料在建筑行业中的应用是一项降低建筑能耗的重要措施。本文介绍了建筑节能相变材料的定义、性能特点及分类,分析了建筑节能相变材料的国内外应用研究现状,并总结出建筑节能相变材料应用研究亟待解决问题,提出了相变材料的应用发展趋势,进而为相变材料在建筑行业中降低能耗的应用提供参考。     

基于粗糙集的夏热冬暖地区建筑能耗关键指标识别研究

对建筑能耗关键指标识别是建筑节能的基础,是进行建筑能耗预测和正确决策的前提。采用文献研究法、专家调查法对住宅建筑能耗指标进行分类,即能源种类指标、能源驱动因素指标、能源用途(能源消耗终端种类)指标。基于粗糙集理论,采用Johnson算法,利用Rosetta软件对建筑能耗关键指标进行识别。结果显示,煤、电、石油液化气、可再生能源是目前建筑能耗中主要的4种能源。人均GDP、人口总量、建筑面积是建筑能耗的主要驱动因素,家用电器、空调、炊事、照明是建筑能耗的主要因素。     

Energy efficiency and building construction in India

The energy conservation has become an important issue in building design, it is logical to apply the principle of energy costing to building projects, and to look for ways to minimize the total energy consumed during their lifetime. Even though the total quantity of energy consumed in a building during its lifetime may be many times than that consumed in its construction, there are number of reasons why the energy use in the construction process, and in particular in the building materials used, should be treated as a matter of importance in looking for ways to minimize energy use in the built environment as a whole. In this paper the energy costs of alternative construction techniques using an optimization framework are assessed and compared. The techniques of construction evaluated in this paper are commonly used pucca techniques as well as low-cost construction techniques. Energy consumption and resource requirements due to the use of alternative techniques of construction for a representative room of size 3.5 m×3.5 m×3.14 m are evaluated. An assessment of the magnitude of energy consumption, if housing shortages have to be met, shows that a huge amount of energy would be consumed in housing sector alone. The associated levels of carbon dioxide emissions associated with this construction would also be prohibitively high. Finally the paper concludes with recommendations for structural changes in the energy and construction policy in India to minimize energy consumption in building construction.     

Optimization of energy consumption in buildings with hydronic heating systems considering thermal comfort by use of computer-based tools

The paper deals with an optimization of parameters, which influence the energy and investment cost as well as the thermal comfort. The parameters considered in this study are: the insulation thickness of the building envelope, the supply-water temperature and the heat exchange area of the radiators. A combination of the building energy simulation software EnergyPlus ¹ and the generic optimization program GenOpt (see footnote 1) has been used for this purpose. The paper presents the application of a one-objective optimization algorithm solving the problems with two objectives, because the optimization algorithm is one-objective and the problem has two objectives, which are minimal total costs and satisfied thermal comfort. The total costs represent the sum of energy consumption and the investment costs. The thermal comfort is represented by Predicted Percentage of Dissatisfied (PPD) in this study. The optimization is used to determine the values of parameters that give the lowest sum of investment and energy cost, under the condition that the thermal comfort is satisfied. In addition, the optimization processes show the mutual influence of parameters on both the total cost and the thermal comfort.     

Inventory analysis of LCA on steel- and concrete-construction office buildings

A life-cycle inventory model for the office buildings is developed in this paper. The environmental effects of two different building structures, steel and concrete, are intercompared. The results show that the steel-framed building is superior to the concrete-framed building on the following two indexes, the life-cycle energy consumption and environmental emissions of building materials. It is found that the life-cycle energy consumption of building materials per area in the steel-framed building is 24.9% as that in the concrete-framed building, whereas, on use phase, the energy consumption and emissions of steel-framed building are both larger than those of concrete-framed building. As a result, lower energy consumption and environmental emissions are achieved by the concrete-framed building compared with the steel-framed building on the whole life cycle of building. The present study also provides a good method of assessing the performance of energy saving and environmental protection of different building structures based on a whole life cycle.     

Comparison between detailed model simulation and artificial neural network for forecasting building energy consumption

There are several ways to attempt to model a building and its heat gains from external sources as well as internal ones in order to evaluate a proper operation, audit retrofit actions, and forecast energy consumption. Different techniques, varying from simple regression to models that are based on physical principles, can be used for simulation. A frequent hypothesis for all these models is that the input variables should be based on realistic data when they are available, otherwise the evaluation of energy consumption might be highly under or over estimated.In this paper, a comparison is made between a simple model based on artificial neural network (ANN) and a model that is based on physical principles (EnergyPlus) as an auditing and predicting tool in order to forecast building energy consumption. The Administration Building of the University of São Paulo is used as a case study. The building energy consumption profiles are collected as well as the campus meteorological data.Results show that both models are suitable for energy consumption forecast. Additionally, a parametric analysis is carried out for the considered building on EnergyPlus in order to evaluate the influence of several parameters such as the building profile occupation and weather data on such forecasting.     

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.     

A generic model of Exergy Assessment for the Environmental Impact of Building Lifecycle

A generic model of Exergy Assessment is proposed for the Environmental Impact of the Building Lifecycle, with a special focus on the natural environment. Three environmental impacts: energy consumption, resource consumption and pollutant discharge have been analyzed with reference to energy-embodied exergy, resource chemical exergy and abatement exergy, respectively. The generic model of Exergy Assessment of the Environmental Impact of the Building Lifecycle thus formulated contains two sub-models, one from the aspect of building energy utilization and the other from building materials use. Combined with theories by ecologists such as Odum, the paper evaluates a building's environmental sustainability through its exergy footprint and environmental impacts. A case study from Chongqing, China illustrates the application of this method. From the case study, it was found that energy consumption constitutes 70-80% of the total environmental impact during a 50-year building lifecycle, in which the operation phase accounts for 80% of the total environmental impact, the building material production phase 15% and 5% for the other phases.     

Implementation of a method in EN ISO 13790 for calculating the utilisation factor taking into account different permeability levels of internal coverings

The general methodology for estimating energy consumption in buildings, in accordance with the EN ISO 13790, needs the use of constants that are valid for each set of climatic conditions. Furthermore, there are variables other than building structure and weather conditions that have an influence. In this sense, recent research works showed the real effect of permeable coverings on indoor environmental conditions, by controlling indoor moisture. The effect of the associated heat and mass transfer on heating or cooling energy consumption is evident during the initial hours of building occupation. In the present paper, the general methodology of building heat demand calculation is modified to consider different levels of permeability of internal coverings, in order to obtain a more accurate model. Results showed that permeable coverings are related with a higher building utilisation factor, and that the value of this factor is higher in summer than in winter season. Consequently, despite the fact that the sensibility of energy consumption to internal coverings may be lower than to building envelope, new constants are proposed to express a relationship between building permeability and energy consumption, in order to apply the certification equation.     

Methodology to estimate building energy consumption using EnergyPlus Benchmark Models

The evaluation of building energy consumption usually requires building energy profiles on an hourly basis. Computer simulations can be used to obtain this information but generating simulations requires a significant amount of experience, time, and effort to enter detailed building parameters. This paper presents a simple methodology to estimate hourly electrical and fuel energy consumption of a building by applying a series of predetermined coefficients to the monthly energy consumption data from electrical and fuel utility bills. The advantage of having predetermined coefficients is that it relieves the user from the burden of performing a detailed dynamic simulation of the building. The coefficients provided to the user are obtained by running EnergyPlus Benchmark Models simulations; thus, the simulation process is transparent to the user. The methodology has been applied to a hypothetical building placed both in Atlanta, GA, and in Meridian, MS, and in both cases, errors obtained for the estimated hourly energy consumption are mainly within 10%.     

小区供热节能改造的新尝试

通过对数个小区供热系统节能情况的调研,证明供热水系统失调和建筑物围护结构的保温性能差是建筑耗能的主要原因。按照分阶段实现民用建筑节能目标的要求,在对供热系统进行改造的同时,抓住住户房屋装修改造的机会,引导住户将房屋的保温改造纳入到装修项目中。通过在两方面的共同努力,解决了供热系统失调问题,提高了供热质量,降低了运行费用。更重要的是通过改造工程的实施,将建筑节能的理念全方位的体现出来,为今后同类小区进行节能改造提供可借鉴的经验。     

A systematic procedure to study the influence of occupant behavior on building energy consumption

Efforts have been devoted to the identification of the impacts of occupant behavior on building energy consumption. Various factors influence building energy consumption at the same time, leading to the lack of precision when identifying the individual effects of occupant behavior. This paper reports the development of a new methodology for examining the influences of occupant behavior on building energy consumption; the method is based on a basic data mining technique (cluster analysis). To deal with data inconsistencies, min-max normalization is performed as a data preprocessing step before clustering. Grey relational grades, a measure of relevancy between two factors, are used as weighted coefficients of different attributes in cluster analysis. To demonstrate the applicability of the proposed method, the method was applied to a set of residential buildings’ measurement data. The results show that the method facilitates the evaluation of building energy-saving potential by improving the behavior of building occupants, and provides multifaceted insights into building energy end-use patterns associated with the occupant behavior. The results obtained could help prioritize efforts at modification of occupant behavior in order to reduce building energy consumption, and help improve modeling of occupant behavior in numerical simulation.     

Life cycle assessment of building materials: Comparative analysis of energy and environmental impacts and evaluation of the eco-efficiency improvement potential

The building industry uses great quantities of raw materials that also involve high energy consumption. Choosing materials with high content in embodied energy entails an initial high level of energy consumption in the building production stage but also determines future energy consumption in order to fulfil heating, ventilation and air conditioning demands.     

公共建筑的多样性及其能效理论的初探

本文分析既有公共建筑的用能特点及其多样性。即地域的用能差异、不同类型公共建筑用能的特点和同类公共建筑运行能耗的差异性。试图对建筑负荷公式按建筑功能的特点加以变量划分和扩展,以变量理论指导各类公共建筑提高运行能效。,最后．提出当前建筑能耗统计中存在的问题,建筑智能化在提高建筑能效中不可替代的作用。     

Enhanced supervision strategies for effective reduction of building energy consumption--A case study of Ningbo

The purpose of this paper is to investigate the reasons for ever growing energy consumption in buildings and to give enhanced supervision strategies for reduction of building energy consumption compared to regular ones. A case study of Ningbo city was used to make a detail analysis. Several factors were determined as the reasons for ever growing building energy consumption including climate change, household electricity load increase, the growth of real estate, fast-growing household electrical appliances, high energy consumption in existing buildings, changes in industrial structure and the lack of enhanced government supervision. Then the discussion of suitable countermeasures shows that only enhanced supervision strategies are currently applicable. Finally, it is concluded that enhanced government supervision strategies, including the establishment of a strict control system for new built buildings through information integration and encryption, establishing an energy efficiency supervision system of large-scale public building and a carrot-and-stick approach with added expert checklist for the building application of renewable energy, showed great advantages in promoting building energy efficiency in Ningbo, compared with other cities. These supervision strategies are applicable in other cities as they are in the similar situations in the enforcement of building energy efficiency.     

Response-relapse patterns of building occupant electricity consumption following exposure to personal, contextualized and occupant peer network utilization data

Behavior can account for significant differences in building energy use. Monitoring and reporting of building energy use may induce occupants to conserve energy. The goal of this study was to assess the behavioral impact of providing building occupants with personal electricity utilization data contextualized with different social frames of reference. We installed monitoring equipment on the electrical meters for 83 rooms of a six-floor residential dormitory building and formulated three study groups and a control group from the building occupants. One study group was provided with their own electricity use, a second group was provided their own electricity use contextualized with average building occupant utilization, and a third group was provided with their own electricity use contextualized with both average occupant utilization and the electricity use of their peer network in the building. The only group that significantly reduced their electricity use when compared to the control group was the study group that could view peer network utilization. All three study groups exhibited response-relapse patterns after viewing their electricity consumption raising important questions about the sustainability of energy conservation and monitoring efforts.     

徐州市普通办公室南向外窗遮阳优化设计分析

建筑节能的议题在当下越来越受重视,对于办公建筑而言,在单位面积各类围护结构中,通过外窗散失的能量是较多的,而合理的遮阳设计将能阻挡绝大部分的太阳直射辐射,降低外窗的能耗。笔者通过数值模拟的方法,对办公室南向外窗遮阳构件尺寸进行定量化模拟分析,使其满足室内光热环境的要求,以最大限度地降低能耗,并为遮阳构件与立面的整合设计提供参考。     

Building typologies as a tool for assessing the energy performance of residential buildings - A case study for the Hellenic building stock

Successful strategies towards minimizing the energy consumption and greenhouse gas emissions attributed to the building sector require knowledge on the energy-related characteristics of the existing building stock. Despite the numerous studies on energy conservation applications in buildings, current knowledge on the energy-related characteristics of the building stock still remains limited. Building typologies can be a useful instrument to facilitate the energy performance assessment of a building stock. This work is based on a harmonised structure for European building typologies (TABULA) developed for residential buildings, but the methodology may be extended to the tertiary sector as well. National typologies are sets of model buildings with characteristic energy-related properties representative of a country's building stock. The model buildings are used as a showcase for demonstrating the energy performance and the potential energy savings from typical and advanced energy conservation measures (ECMs) on the thermal envelope and the heat supply system. The proposed Hellenic residential building typology is presented for the first time along with an assessment of various ECMs that are used for an estimate of the energy performance of building stock in Greece in an effort to meet the 9% indicative national energy savings target by 2016.     

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.