Evaluation of the corrected seasonal energy demand, for buildings classification, to be compared with a standard performance scale

In the European panorama, the relevant increase of the buildings energy consumptions has resulted, from the normative point of view (European directive 2002/91/EC [European Parliament and Council of December 16th, 2002 on the energy performance of buildings, Official Journal of the European Communities, L 1/65] and the relative national norms - for example Italian Decrees 192/05-311/06), in the imposition of minimum standards of construction, limiting the specific energy requirements specifically for heating and cooling. Moreover, in some countries it is being started to introduce, for buildings that respect the minimum performances levels imposed, incentive and defiscalization measures, function of their particular energetic efficiency and the corresponding performance class.Therefore, to compare the construction quality of different buildings, through energy performance classification, the authors propose a procedure for the determination of the corrected energy demand, separately for heating and cooling, independent of buildings location and directly comparable to a standard seasonal performance scale, defined on the entire territory of application.The procedure is so developed through simulation on a wide range of case-studies and then tested on a different buildings set: its effectiveness results in the attribution to each building test of an univocal performance class, providing an energy performance evaluation not affected by the building localization.     

Data collection and analysis of the building stock and its energy performance—An example for Hellenic buildings

The process of building labeling and certification in accordance to the provisions of the European Directive on the Energy Performance of Buildings (EPBD) constitutes a unique opportunity for collecting information on the characteristics of the building stock and its energy performance on a national and European level. Thus, there is a need to handle data from a large stock of buildings and to be able to analyse information and extract practical trends and benchmarks. Stakeholders and technical managers who oversee a number of buildings experience similar needs in order to collect, organize and monitor the energy performance of a large pool of buildings. To facilitate these efforts, a common evaluation database and complimentary software for its exploitation have been developed in the frame of a European project.This paper presents an overview of the database and its available tools, and the main results from a case study on Hellenic buildings that reveals relevant characteristics. The Hellenic database included a sample of 250 buildings from different regions in Greece, with a breakdown that is representative of the national building stock. The main results focus on the buildings’ energy performance, thermal envelope characteristics and the exploitation of solar thermal energy.     

A review of benchmarking, rating and labelling concepts within the framework of building energy certification schemes

Energy certification schemes for buildings emerged in the early 1990s as an essential method for improving energy efficiency, minimising energy consumption and enabling greater transparency with regards to the use of energy in buildings. However, from the beginning their definition and implementation process were diffuse and, occasionally, have confused building sector stakeholders. A multiplicity of terms and concepts such as energy performance, energy efficiency, energy ratings, benchmarking, labelling, etc., have emerged with sometimes overlapping meanings. This has frequently led to misleading interpretations by regulatory bodies, energy agencies and final consumers.This paper analyses the origin and the historic development of energy certification schemes in buildings along with the definition and scope of a building energy certificate and critical aspects of its implementation. Concepts such as benchmarking tools, energy ratings and energy labelling are clarified within the wider topic of certification schemes. Finally, a seven steps process is proposed as a guide for implementing building energy certification.     

The characteristics and the energy behaviour of the residential building stock of Cyprus in view of Directive 2002/91/EC

The significance of the residential building sector in terms of energy consumption is well acknowledged. In this view the knowledge of the way the residential building stock of Cyprus behaves in terms of energy consumption is quite valuable since it will assist policy makers to formulate targeted measures aiming the improvement of energy efficiency and setting current legal standards and benchmarks in the energy performance certificate, a requirement of the 2002/91/EC Directive. Unfortunately, the existing knowledge on this subject is quite poor. As a remedy a research project supported by a national research grant is in operation since December 2008. This paper presents the outline, goals and methodology of this research project and the findings regarding the energy behaviour and other characteristics of the residential building stock of Cyprus. From the analysis of the results for 500 residential buildings, it seems that the energy demand and primary energy required is lower than that of other European countries. Moreover, it seems that the age of residential buildings has low correlation with the energy demand while in contrast with other Northern and Central European countries, it is clear that the contribution of cooling energy requirements to the overall energy demand is quite significant.     

Energy performance assessment of existing dwellings

The existing buildings stock in European countries accounts for over 40% of final energy consumption in the European Union (EU) member states, of which residential use represents 63% of total energy consumption in the buildings sector. Consequently, an increase of building energy performance can constitute an important instrument in the efforts to alleviate the EU energy import dependency and comply with the Kyoto Protocol to reduce carbon dioxide emissions. This is also in accordance to the European Directive on the energy performance of buildings (EPBD), which has come to effect on 4 January 2006. The energy performance assessment for existing dwellings (EPA-ED) is a new methodology supported by software, developed in the framework of a European project that focuses on energy related issues for existing residential buildings, in line with the EPBD. This paper presents an overview of the method and software that can be used to perform building energy audits and assess buildings in a uniform way, perform demand and savings calculations, provide owners with specific advice for measures to improve energy performance, issue an energy performance certificate for existing buildings, and include some representative results from the pilot studies performed in several European countries. Also the sister-method EPA-NR, on non-residential buildings, currently under construction, is introduced.     

Evaluation of traditional architecture in terms of building physics: Old Diyarbakír houses

Diyarbak?r is located in the southestern part of Turkey. Traditional Diyarbak?r houses are successful examples of buildings adapted to a hot dry climate. This is achieved by conforming to an old style of living and by the requirements and the use of local materials. In this study, the general architectural properties of the traditional houses of Diyarbak?r, their layouts, plan types, building envelope and facade elements are evaluated in terms of building physics criteria. Today, in spite of new technological advances, techniques and materials, identical buildings are still being built, and climatic design is not considered important in Diyarbak?r. As a result these buildings do not provide shade and cool spaces, and thus cause thermal discomfort, or increase in the use of energy. The aim of this study is to emphasize the importance of the features of traditional buildings in terms of designing energy efficient, to provide appropriate buildings for the environment.     

重庆地区居住建筑遮阳构筑物对建筑能耗的影响

太阳辐射对供暖、空调负荷有重要的影响,而窗口的遮阳是改善住宅能耗的一个重要措施.以单位面积建筑能耗作为衡量遮阳效果的指标,结合重庆当地气候特征,分析了Low-E玻璃和水平遮阳板的遮阳性能对建筑能耗的影响.并在综合考虑冬、夏节能不同需求的基础上,给出了适合重庆地区使用的Low-E节能玻璃和水平遮阳板的设置方式.     

Legrand照明节能产品及解决方案的设计和研究

摘要罗格朗的感应器系列及灯光管理系统产品为各类新建、改造建筑提供了全方位的能效管理解决方案,有助于能源节约,满足中国绿色建筑标识以及LEED认证的要求。     

Comparative study of energy regulations for buildings in Italy and Spain

In this study the Italian and Spanish national regulations related to the transposition of Directive 2002/91/EC on energy efficiency in buildings are compared. Three typical buildings were selected for the comparison: a semidetached house, an independent house and an apartment. These buildings were located in different climatic zones of each country and simulated with different orientations. The energy standards in Italy, Decree 192/05, valid for years 2006, 2008 and 2010, and in Spain, the Código Técnico de Edificación, were also compared with the German standard called Passivhaus. The contribution to total energy demand of winter and summer energy demands was evaluated, along with a statistical distribution of the consumptions for the various climatic zones and orientations. The increase in the energy consumption limitations in Italy over the years was also analysed. The results show that the least restrictive Italian regulation, i.e. the one valid for the year 2006, is more restrictive than the Spanish regulation.     

Assessment of innovative ventilation in the framework of the EPBD—A probabilistic approach: RESHYVENT project

The market uptake of innovative, energy efficient concepts in the building sector is to a large extent influenced by the stimuli found in building regulations. The Energy Performance of Buildings Directive (EPBD) makes the application of an EPB regulation mandatory for new buildings and for major renovations. If one is obliged to make an assessment of buildings in terms of energy performance, it is clear that one should be able to assess all kinds of building designs and of technologies. However, the EPB regulations (present or under development) clearly not cover all possible technologies. Among the technologies that are typically not covered by the standard procedures are innovative ventilation concepts, e.g. hybrid ventilation in dwellings. This paper wants to highlight the need for the development of a coherent approach, based on a mixture of European measures and national actions.     

Artificial intelligence tools and inverse methods for estimating the thermal diffusivity of building materials

The actual European energy context highlights the building sector as one of the largest sectors of energy consumption. Consequently, the “Energy Performance of Buildings Directive”, adopted in 2002 and focusing on energy use in buildings, requires all the EU members to enhance their building regulations and to introduce energy certification schemes, with the aim of both reducing energy consumption and improving energy efficiency. That is why carrying out an energy performance diagnosis is mandatory, notably when buying or selling properties. Indeed, invisible defaults, like, for example, non-emerging cracks or delaminations, could have a detrimental effect on insulating qualities. Esimaing in situ thermo-physical properties allowing locating these defaults, the present work focuses on proposing new and efficient approaches based on the use of both artificial intelligence tools (artificial neural networks and neuro-fuzzy systems) and inverse methods for characterizing building materials i.e. for estimating their thermal diffusivity using thermograms obtained thanks to a non-destructive photothermal method.     

Evaluation of energy efficient design strategies for different climatic zones: Comparison of thermal performance of buildings in temperate-humid and hot-dry climate

Since the Kyoto protocol signed in December 1997 the majority of governments around the world have committed themselves to reducing the emission of the greenhouse gases. Thus, efficient use of energy and sustainability has become a key issue for the most energy policies. Sustainability and energy saving terms take place in building construction industry too since buildings are one of the most significant energy consumers. It is known that heating energy demand of a building has a great rate in building total energy consumption. In addition to that, the most of the heating energy has been lost from building envelope. TS 825, Heating Energy Conservation Standard for Buildings in Turkey, aims the reducing of heat loss in buildings through the envelope. But within buildings, one of the fastest growing sources of new energy demand is cooling and especially in hot-humid and hot-dry climatic parts of Turkey cooling season is much longer than the heating season. Moreover in hot-dry climate heat storage capacity of the envelope becomes more important issue than heat insulation for energy efficiency of the building. Since the Turkish standard is considering only heating energy conservation by using degree-day concept, Istanbul and Mardin are considered in the same zone, however those are in temperate-humid and hot-dry climatic zones, respectively. In this study energy efficient design strategies for these climatic zones have been explained and thermal performance of two buildings, which are constructed according to the TS 825 in Mardin and Istanbul cities were evaluated to show the importance of thermal mass in hot-dry climates.     

A Round Robin Test for buildings energy performance in Italy

The energy policy in Europe regarding buildings and the energy efficiency sector are regulated by two directives: 2002/91/CE - EPBD and 2006/32/CE - EEESD [1] and [2].The CEN has elaborated a standard to revise all European normatives about building energy performance and HVAC plants. The “CEN Umbrella” CEN/TR 15615 [3] includes a new version of EN ISO 13790:2008 [4] and a new standard about heating plant, use and contributions of renewable energy sources. Furthermore, the CEN Standard provides a software version for technicians.In this paper we present a Round Robin Test between a selection of softwares applied to an Italian case study. The selected calculation methodologies, range from research packages to extra-simplified software. Furthermore, the Italian procedure described in UNI TS 11300 [5] has been analyzed and considered as the reference for all other calculation methodologies.The results of the Round Robin Test show the relationship between thoroughness of data input and energy evaluation accurancy. The more the input data is affected by uncertainty, the less precise is the energy efficiency calculation. On the other hand the energy performance of building evaluation accurancy depends on the aim of the simulation: the energy audit, the energy design or the energy labeling (certification).     

政策法规对建筑节能的作用——欧盟经验参考

简要介绍了欧盟建筑能效指令EPBD的主要内容,并从建立建筑能耗计算方法、规定建筑最小能耗要求、建立建筑能耗证书制度等方面分析建筑节能政策对欧盟国家建筑节能的影响,以便为我国建筑节能政策的制定和执行提供参考。     

Comparing cost-optimal and net-zero energy targets in building retrofit

The recast of the European Union's Energy Performance of Buildings Directive introduced the concept of nearly zero-energy buildings, requiring its adoption from 2021 by all new buildings and existing ones submitted to major renovations. European Union member states must also ensure minimum energy requirements for buildings in order to achieve cost-optimal levels during their life cycle. Cost optimality and nearly zero-energy buildings are important concepts in European Union energy policies. These concepts are related, but one is more focused on costs, while the other is more concerned with low energy consumption and on site-renewable energy harvesting. If these approaches result in major differences in the selection of the best package of retrofit measures, then the transition from the cost-optimal concept to nearly zero-energy buildings might be problematic. To assess the most cost-effective solutions to achieve net-zero, a building in Porto, Portugal, was analysed. This determined not only the most cost-effective retrofit solutions but also compared these net-zero solutions with those resulting from the cost-optimal calculation. Both approaches lead to similar results, indicating that the transition between ‘cost optimality’ to ‘nearly zero-energy buildings’ could occur in Portugal.     

Influence of climate change on the energy efficiency of light-weight steel residential buildings

This paper addresses the influence of the climate change scenarios predicted by the Intergovernmental Panel for Climate Change (IPCC) for Southern Europe and the Mediterranean region on the energy efficiency of light-weight steel residential buildings. A performance-based approach is adopted to carry out this assessment using advanced dynamic simulation of the operational energy performance. Based on a typical Portuguese cold-formed steel residential building, a representative numerical model is calibrated against normative requirements for dynamic simulation of thermal behaviour and sophisticated computational fluid dynamics models. Considering climate change scenarios predicted by the IPCC, a parametric study is carried out to assess the influence of climate change on the energy efficiency of light-weight steel residential buildings representative of a warm temperate summer dry climatic region.     

Do LEED-certified buildings save energy? Yes, but…

We conducted a re-analysis of data supplied by the New Buildings Institute and the US Green Buildings Council on measured energy use data from 100 LEED-certified commercial and institutional buildings. These data were compared to the energy use of the general US commercial building stock. We also examined energy use by LEED certification level, and by energy-related credits achieved in the certification process. On average, LEED buildings used 18-39% less energy per floor area than their conventional counterparts. However, 28-35% of LEED buildings used more energy than their conventional counterparts. Further, the measured energy performance of LEED buildings had little correlation with certification level of the building, or the number of energy credits achieved by the building at design time. Therefore, at a societal level, green buildings can contribute substantial energy savings, but further work needs to be done to define green building rating schemes to ensure more consistent success at the individual building level. Note, these findings should be considered as preliminary, and the analyses should be repeated when longer data histories from a larger sample of green buildings are available.     

夏热冬暖地区高校既有建筑绿色改造设计策略研究

在目前全面推进生态文明建设的背景下,"绿色"发展理念和"碳中和"的设计理念将日益深入人心。我国大学校园的建筑存量大,大学校园既有建筑绿色改造具有重要的现实节能减排意义和生态文明教育推广作用。针对夏热冬暖地区的地域和气候特点,结合实际的高校建筑绿色改造项目,从遮阳隔热、通风、水循环、复合绿化与资源利用等方面建构系统性的高校既有建筑绿色改造设计策略,为解决大学校园建筑的能耗问题和提升校园建筑的环境性能提供思路。     

Optimisation of opaque components of the building envelope. Energy,economic and environmental issues

The European Directive 2002/91 will enforce the Member State to promote the implementation of new measures, instruments and calculation methodology to improve the buildings energy performances. The thermal performance and quality of the Italian residential buildings is generally poor, depending on the age of the building stock and the lack of application of the existing energy regulations. This study aims at demonstrating the global benefits of good insulated building envelopes. Energy benefits are easy to understand, meanwhile the economic issues are critical, since the final users see them as an additional useless extra cost for the dwelling at the purchase phase, with small attention to the future managing costs. The study demonstrates that significant economic advantages come out from high–performance building envelope. The study also shows that environmental extra loads due to a bigger use of the insulating material is paid back in few years, with consistent social benefits, if the life cycle of the building is taken into account.     

Towards a universal energy efficiency index for buildings

The growing worldwide demand for energy is basically satisfied through natural resources such as oil or natural gas generally acknowledged as being responsible for climate change through greenhouse gas emissions. The building sector accumulates approximately a third of the final energy consumption. Consequently, the improvement of the energy efficiency in buildings has become an essential instrument in the energy policies to ensure the energy supply in the mid to long term, and to meet the targets stated in the Kyoto Protocol. During the last decade and being sensitive to this fact, many national governments and international organizations have developed new regulations to achieve those targets. One of these regulations is the European Energy Performance of Buildings Directive but, to date this certification does not follow a standard procedure which is universally accepted.This paper aims to contribute to this standardization, proposing an energy efficiency index for buildings that relates the energy consumption within a building to reference consumption. The proposed energy index can be obtained in a simple manner by combination standard measurements of energy consumption, simulation and public databases. Furthermore, the index is upgradable whenever new data are available.