Statistical analysis of the Greek residential building stock

The latest developments in the field of energy supply, along with the major issue of the environment protection, set new priorities and yardsticks concerning the energy policies implemented worldwide. The development and implementation of effective energy conservation policies has been a target of the European Union ever since the days when it was still called European Economic Community. In this framework, and despite the successes already monitored, the need for further energy conservation in the building sector is a both an aim and a tool. Emphasis is being placed on the residential building stock and the improvement of its energy performance. Greece has been one of the last countries to adopt the Directive on the Energy Performance of Buildings. A thorough research regarding the nature of the Greek residential building stock helps in highlighting the problems associated with this delay, but also the perspectives for catching up with the other EU member states and achieving the aims set for the coming years. This paper aims at providing detailed information on the residential urban building stock, as determined in a field study in typical big and smaller Greek cities.     

Energy savings in a building using regenerative evaporative cooling

This paper explores the potential of reducing the annual energy consumption of a central air-conditioned building through advanced evaporative cooling systems. The building considered is a typical three floor library building of a University. The regenerative evaporative cooling technology is coupled with the liquid cooled water chiller system to accomplish the energy conservation objective. Comparisons of the regenerative evaporative cooling are made with simple evaporative cooling to bring out the importance such a system. The well-known building simulation software, TRNSYS is used to carry out the heat load calculations and the dynamic simulations of the building. Annual energy consumptions of different components of the air-conditioning system are estimated for the existing water chiller system as well as for both coupled evaporative cooling systems (simple and regenerative). The annual energy consumptions, the indoor temperature, the relative humidity and the thermal comfort index ‘PMV’ are compared for all the three different air-conditioning systems. The coupling of direct and regenerative evaporative cooling technologies with water chiller system has shown, respectively, 12.09% and 15.69% savings in annual energy consumption of the building, while maintaining PMV between ?1 and +1 for most of the hours in the year.     

European residential buildings and empirical assessment of the Hellenic building stock,energy consumption,emissions and potential energy savings

The existing building 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 (currently at about 48%) and comply with the Kyoto Protocol to reduce carbon dioxide emissions. This is also in accordance to the European Directive (EPBD 2002/91/EC) on the energy performance of buildings, which is currently under consideration in all EU member states. This paper presents an overview of the EU residential building stock and focuses on the Hellenic buildings. It elaborates the methodology used to determine the priorities for energy conservation measures (ECMs) in Hellenic residential buildings to reduce the environmental impact from CO₂ emissions, through the implementation of a realistic and effective national action plan. A major obstacle that had to overcome was the need to make suitable assumptions for missing detailed primary data. Accordingly, a qualitative and quantitative assessment of scattered national data resulted to a realistic assessment of the existing residential building stock and energy consumption. This is the first time that this kind of aggregate data is presented on a national level. Different energy conservation scenarios and their impact on the reduction of CO₂ emissions were evaluated. Accordingly, the most effective ECMs are the insulation of external walls (33–60% energy savings), weather proofing of openings (16–21%), the installation of double-glazed windows (14–20%), the regular maintenance of central heating boilers (10–12%), and the installation of solar collectors for sanitary hot water production (50–80%).     

A typological classification of the Greek residential building stock

Based on the European Directive on the Energy Performance of Buildings a new regulation framework has recently been implemented in Greece, aiming at the CO₂ emissions reduction caused by the building sector. Given the fact that almost 71% of the Greek buildings were constructed before the implementation of the first Thermal Insulation Regulation (TIR), emphasis must be laid upon the existing building stock. Moreover, 83% of this stock consists of residential buildings, indicating the large potential in energy conservation. In order to plan and promote the respective energy renovation scenarios, a thorough analysis of the Greek building stock has to be carried out, especially regarding the urban built environment. In order to achieve this, a classification of the dominating multifamily building typology is being presented and characteristic examples are being studied.     

谈福建省居住建筑节能技术措施

根据福建地区的气候特点及福建省居住建筑围护结构热工特性,从合理建筑设计、改善外窗、外墙、屋顶等建筑围护结构热工性能方面入手,采取一定的节能技术措施,提高居住建筑的舒适水平。     

Energy consumption and conservation in the Russian apartment building stock

Energy consumption of buildings in Russia and other states of the former Soviet Union has typically been reported in very coarse terms, as annual energy use normalized by weather and floor area. Reported figures, based on estimates derived from available energy-delivery data, have shown that Russian residential buildings consume on the order of twice as much primary energy for space-heating as those in some developed Western countries. Reports have been accompanied with qualitative assertions that higher levels of insulation, reduced air infiltration, and better control of heating systems could reduce energy use. However, there has been a dearth of data that first distinguish Russian buildings by construction type and insulation level, and second attempt to quantitatively pinpoint causes for the relatively high energy use. Such data are needed to focus contemporary energy-conservation efforts in Russia on the most promising areas. This paper presents a preliminary set of information that illuminates these areas, concentrating on the city of Moscow. The analysis breaks down Moscow's district-heated apartment building stock by type and year of construction and by the required thermal standards in force at the time of construction. It aggregates these buildings into three classes according to the type of external wall construction — brick or large block, single-layer panel, and three-layer panel — and estimates overall annual energy use for space-heating via a steady-state model. It then compares predicted and measured energy use, for the aggregation and, more accurately, for a single building for which detailed energy-use data are available. In both cases there is a large discrepancy, with actual space-heating energy use exceeding design predictions by at least 60%. Analytical efforts to reconcile the excess energy consumption for the metered building strongly suggest that the most important cause of relatively high space-heating energy use in the building is poor control of heat delivery from the district heating system.     

石家庄市新建居住建筑节能措施

运用实例从围护结构、新能源以及供热系统三个方面对石家庄市新建居住建筑节能措施进行了论述,为寒冷地区居住建筑节能提供参考。     

Policy options towards an energy efficient residential building stock in the EU-27

The EU-27 residential building stock offers high potential for energy efficiency gains. The policies already in place or proposed to improve the energy efficiency and thus the environmental performance focus on new buildings and major renovations of existing buildings. However, there might be additional measures that could lead to further energy efficiency improvements. In particular, the installation of roofs or windows that show a high thermal efficiency outside major renovations offer a large improvement potential. In this study, the potential environmental and economic impacts of two types of such policy options were analysed: first, measures that require high energy efficiency standards when roofs or windows have to be replaced; and, second, measures that accelerate the replacement of building elements. The results suggest that the two policies offer the potential for substantial additional energy savings. In addition, the installation of energy efficient building elements comes at negative net cost. When the replacement of building elements is accelerated, however, the additional costs do not outweigh the energy cost savings.     

Energy efficiency and energy savings in Japanese residential buildings—research methodology and surveyed results

Worldwide energy consumption has risen 30% in the last 25 years. Fossil fuels exploitation is causing depletion of resources and serious environmental problems. Energy efficiency improvement and energy savings are important targets to be achieved on every society as a whole and in residential buildings in particular. In this article, results of a survey and questionnaire on energy consumption and thermal environment held in Kansai area, Japan are reported. Energy savings potential was analyzed for the surveyed 13 houses focusing on certain electrical appliances e.g. TV, rice cooker and refrigerator. Residents’ environmental awareness towards energy consumption was clarified through questionnaire. An energy information session towards residents was held, and the resulting changes in lifestyle and their implications on energy consumption were evaluated.     

A review of bottom-up building stock models for energy consumption in the residential sector

Efficient and rational implementation of building stock CO₂ emission reduction strategies and policies requires the application of comprehensive building stock models that have the ability to: (a) estimate the baseline energy demand of the existing building stock, (b) explore the technical and economic effects of different CO₂ emission reduction strategies over time, including the impact of new technologies, and (c) to identify the effect of emission reduction strategies on indoor environmental quality.     

Evaluation of advanced control strategies of electric thermal storage systems in residential building stock

This paper investigates the effect of different control strategies applied to electric thermal storage systems to provide demand response services. These results indicate how policymakers or manufacturers could target the implementation of advanced control on electric thermal storage systems and apply these to households characterised by different occupancy profiles, thereby making demand response initiatives more attractive to end users.     

Energy savings potential of a desiccant assisted hybrid air source heat pump system for residential building in hot summer and cold winter zone in China

In hot summer and cold winter zone in China, air conditioning system has four running modes yearly including cooling with dehumidification, cooling, dehumidification and heating in residential buildings. The conventional air source heat pump (ASHP) system is not designed to independently control temperature and humidity, and is not very suitable for the dehumidification mode in the view of building energy consumption. A novel ASHP system combining radiant cooling/heating for residential buildings was presented. The main feature of this hybrid ASHP system is that desiccant wheel and cooling coil accomplish dehumidification process together, and the regenerative heat needed by the desiccant wheel is supplied by the condenser dissipated heat. Based on simulation studies and performance analysis, this paper predicts the primary energy consumption of the hybrid ASHP system in comparison with the conventional ASHP system during the cooling and heating seasons. It was found that primary energy requirement can be reduced by more than 8% in cooling with dehumidification mode, by 50% in dehumidification mode, and by more than 14% in heating mode. The study results prove that the hybrid ASHP system can keep great energy saving and running cost saving yearly, especially in the dehumidification process.     

Resilience to increasing temperatures: residential building stock adaptation through codes and standards

The resilience of the current Spanish residential building stock to increased temperatures is modelled. Homogenized daily temperature data recorded at 50 Spanish meteorological stations for the periods 1950–1979 and 1981–2010 were used to investigate anticipated climate warming on the Spanish residential building stock by means of the degree-day method. Impacts on residential buildings were investigated for three different future time periods (2011–2040, 2041–2070 and 2071–2100) for three representative Spanish provincial capitals. Future climate change scenarios comprising two statistical downscaling methods, three general circulation models and two carbon emission scenarios were used to project local climate. Results show that 72% of current residential building stock in Spain is thermally unprotected. In addition, the energy demand for heating the building sector in Spain is expected to decrease by between 30% (Barcelona, B2 scenario) and 36% (Valencia, A2 scenario) by 2100, while the respective energy demand for cooling could increase by between 107% (Valencia, B2 scenario) and 296% (Madrid, A2 scenario) by 2100. To increase resilience to higher winter and summer temperatures, strategies for modifying the built environment are needed, particularly for the role of building codes and standards.

La résilience du parc bâti résidentiel espagnol actuel face à l'augmentation des températures est modélisée. Les données homogénéisées des température journalières enregistrées dans 50 stations météorologiques espagnoles pour les périodes 1950–1979 et 1981–2010 ont été utilisées pour étudier le réchauffement climatique prévu sur le parc bâti résidentiel espagnol en utilisant la méthode des degrés-jours. Les répercussions sur les immeubles résidentiels ont été étudiées pour trois périodes futures différentes (2011–2040, 2041–2070 et 2071–2100) et pour trois capitales provinciales espagnoles représentatives. Il a été utilisé des scénarios de changement climatique futur comprenant deux méthodes de réduction d'échelle statistique, trois modèles de circulation générale et deux scénarios d'émission de carbone pour prévoir le climat local. Les résultats montrent que 72 % du parc bâti résidentiel actuel de l'Espagne est dépourvu de protection thermique. Il est en outre prévu que la demande énergétique liée au chauffage dans le secteur du logement en Espagne diminue de 30 % (Barcelone, scénario B2) à 36 % (Valence, scénario A2) d'ici à 2100, tandis que la demande énergétique respective liée à la climatisation pourrait augmenter de 107 % (Valence, scénario B2) à 296 % (Madrid, scénario A2) d'ici à 2100. Afin d'augmenter la résilience face à des températures hivernales et estivales plus élevées, il est nécessaire de disposer de stratégies de modification du cadre bâti, concernant en particulier le rôle des codes et des normes du bâtiment.

Mots clés: stratégies d'adaptation, performances des bâtiments, réglementation du bâtiment, parc bâti, changement climatique, degrés-jours, surchauffe, confort thermique, vulnérabilité, Espagne     

北京市地方标准《居住建筑节能设计标准》简介

回顾了全国和北京市《居住建筑节能设计标准》的编制工作,介绍了对2012年版北京市标准中节能率的理解及其实现方法,以及标准中关于室内计算参数的规定。对比了3个标准关于建筑热工设计及围护结构热工性能权衡判定方法的规定。介绍了该标准中有关暖通空调及给排水、电气节能设计的规定。     

Potential for potable water savings by using rainwater and greywater in a multi-storey residential building in southern Brazil

Studies on the use of rainwater and greywater to promote potable water savings have been performed in different countries. The main objective of this article is to evaluate the potential for potable water savings by using rainwater and greywater in a multi-storey residential building composed of three blocks, located in Florianópolis, southern Brazil. Water end-uses were estimated by applying questionnaires and measuring water flow rates. An economic analysis was performed to evaluate the cost effectiveness of using rainwater and greywater either separately or together. Results show that the average potential for potable water savings range from 39.2% to 42.7% amongst the three blocks, considering that water for toilet flushing, clothes washing and cleaning does not need to be potable. By using rainwater, the potable water savings would actually range from 14.7% to 17.7%. When greywater is considered alone, potable water savings are higher, i.e., ranging from 28.7% to 34.8%. As for the use of rainwater and greywater combined, the potable water savings range from 36.7% to 42.0%. The main conclusion that can be made from the research is that the three systems that were investigated are cost effective as the payback periods were lower than 8 years, but the greywater system was the most cost effective one, followed closely by the rainwater one.     

住宅建筑楼梯间供暖问题探讨

经理论分析和实例计算,提出了在围护结构相同的条件下,楼梯间设供暖比不设供暖能耗大。     

浅析青海省新建城镇住宅建筑围护节能措施

本文规划设计了青海省城镇住宅建筑的围护节能计划,找出了相对适合青海省本土新建城镇住宅建筑的围护节能措施,并希望能将该建筑节能技术措施进行推广和应用。     

建筑节能在居住建筑设计中的应用

从建筑节能与规划设计、围护结构设计、周围环境设计这三个方面综合考虑建筑节能的一些技术手段,从设计的角度提出建造节能建筑的新思路,以引导人们进一步重视建筑节能,提高资源利用率,改善生态环境。     

某高层剪力墙住宅结构减震分析与设计

将铅剪切阻尼器应用于某高层剪力墙住宅结构的减震分析与设计中,经过多次试算分析得到了阻尼器的优化布置方案。小震下的弹性时程分析和大震下的静力弹塑性分析结果表明,铅剪切阻尼器的减震率达到了40%,可以使该结构的抗震能力约提高1度。对布置阻尼器后的结构竖向承载力进行了验算,并对有关部位、附加剪力墙配筋和预埋件进行了设计。     

Variation in residential radon levels in new Danish homes

Radon‐222 gas arises from the radioactive decay of radium‐226 and has a half‐life of 3.8 days. This gas percolates up through soil into buildings, and if it is not evacuated, there can be much higher exposure levels indoors than outdoors, which is where human exposure occurs. Radon exposure is classified as a human carcinogen, and new Danish homes must be constructed to ensure indoor radon levels below 100 Bq/m³. Our purpose was to assess how well 200 newly constructed single detached homes perform according to building regulations pertaining to radon and identify the association between indoor radon in these homes and municipality, home age, floor area, floor level, basement, and outer wall and roof construction. Median (5–95 percentile) indoor radon levels were 36.8 (9.0–118) Bq/m³, but indoor radon exceeded 100 Bq/m³ in 14 of these new homes. The investigated variables explained nine percent of the variation in indoor radon levels, and although associations were positive, none of these were statistically significant. In this study, radon levels were generally low, but we found that 14 (7%) of the 200 new homes had indoor radon levels over 100 Bq/m³. More work is needed to determine the determinants of indoor radon.