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The present paper deals with the energy performance, energy classification and rating and the global environmental quality of school buildings. A new energy classification technique based on intelligent clustering methodologies is proposed. Energy rating of school buildings provides specific information on their energy consumption and efficiency relative to the other buildings of similar nature and permits a better planning of interventions to improve its energy performance. The overall work reported in the present paper, is carried out in three phases. During the first phase energy consumption data have been collected through energy surveys performed in 320 schools in Greece. In the second phase an innovative energy rating scheme based on fuzzy clustering techniques has been developed, while in the third phase, 10 schools have been selected and detailed measurements of their energy efficiency and performance as well as of the global environmental quality have been performed using a specific experimental protocol. The proposed energy rating method has been applied while the main environmental and energy problems have been identified. The potential for energy and environmental improvements has been assessed. © 2006 Elsevier B.V. All rights reserved.

Measurements of indoor air pollutants covering the concentrations of CO2, CO, TVOC's, PM2.5, and PM10 were performed in 50 residences in Athens. In addition the ventilation rate in each dwelling was continuously measured by monitoring CO2 concentration. Apart from carbon monoxide, almost all the remaining pollutants showed high concentrations that exceeded the maximum threshold levels of the relevant standards. The rate of ventilation was found to have a very important impact on the concentration of indoor pollutants. Finally, the impact of tobacco smoking was found to be very important and the concentration of almost all pollutants increased significantly when the rate of smoking increased.

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The utilizability or φsymbol-curve method is a design method for some types of solar energy systems that use flat-plate solar collectors. It can be a very useful design tool, for the preliminary design or the design of small systems, cases where methods easy to use and apply are required. In this paper, a simple method to calculate monthly average hourly and daily flat plate collector utilizability is presented. It is based on empirical correlation of φsymbol with independent variables that separate meteorological and collector parameters, making possible quick evaluations of changes in collector design and collector inlet temperature. In general, the method reduces the calculations required to determine φsymbol, and gives good results compared to long-term hourly simulations as well as to existing hourly and daily utilizability calculations methods. © 2006 Elsevier Ltd. All rights reserved.

The present paper aims to present a distant-learning training module that concerns the environmental design of urban buildings. The whole approach attempts to integrate topics that concern the design of urban buildings from various points of views, e.g. active and passive systems, automation systems, indoor air quality, economic aspects, energy and resources management. The package offers both printed and electronic material that gives the possibility to the students to study the various topics by using different educational methods. Additionally, the present package contains software tools that permit the students to examine real or hypothetical situations and to study further the influence of various parameters that concern the environmental building design. © 2005 Elsevier Ltd. All rights reserved.

This paper discusses how neural networks, applied to predict energy consumption in buildings, can advantageously be improved, guided by statistical procedures, such as hypothesis testing, information criteria and cross validation. Recent literature has provided evidence that such methods, commonly used independently, when exploited together, can improve the selection and estimation of neural models. We use such an approach to design feed forward neural networks for modeling energy use and predicting hourly load profiles, where both the relevance of input variables and the number of free parameters are systematically treated. The model building process is divided in three parts: (a) the identification of all potential relevant input, (b) the selection of hidden units for this preliminary set of inputs, through an additive phase and (c) the remove of irrelevant inputs and useless hidden units through a subtractive phase. The predictive performance of short term predictors is also examined with regard to prediction horizon. A comparison of the predictive ability of a single-step predictor iteratively used to predict 24 h ahead and a 24-step independently designed predictor is presented. The performance of the developed models and predictors was evaluated using two different data sets, the energy use data of the Energy Prediction Shootout I contest, and of an office building, located in Athens. The results show that statistical analysis as an integral part of neural models, gives a valuable tool to design simple, yet efficient neural models for building energy applications. © 2005 Elsevier B.V. All rights reserved.

This article deals with the energy performance of eight new and existing museum buildings located around Europe. Various energy efficiency and microclimate improvement measures have been adopted to reduce the energy consumption of the buildings and improve the comfort conditions. The investigation was implemented in two principal phases. During the first phase, energy simulation studies were performed in all buildings to evaluate the efficiency of the proposed measures and the various design possibilities. The energy consumption for heating, cooling, lighting and other electrical devices was calculated with and without the application of the proposed techniques and the corresponding energy conservation was estimated. Therefore, the proper measures from the energy point of view were adopted. During the second phase, measurements of the energy consumption were performed in the buildings after the finalization of the construction and the implementation of the proposed measures. The energy conservation was again calculated to evaluate the energy efficiency of the final construction. In addition to the energy aspect, the environmental impact of the final construction of the museums was investigated by calculating the reduction of the CO2 emissions due to the applied energy conservation techniques. Finally, the economic efficiency was examined by assessing the payback period of the adopted measures. The results of the present work show that the adaptation of energy conservation techniques in museums buildings can reduce significantly the energy consumption by respecting at the same time the requirements of the exhibition spaces and the comfort conditions of the visitors.

The archaeological museum of Delphi is one of the most visited museums in Greece with visitors ranging from about 150,000 to 300,000 per year. The building was retrofitted as a result of the Greek case study in the demonstration project 'MUSEUMS - Energy Efficiency and Sustainability in Retrofitted and New Museum Buildings' which was executed within the fifth Framework Programme of the European Commission DG TREN (Energie Programme). The retrofitting works aimed to integrate bioclimatic and sustainable measures in the existing exhibition halls, to minimize energy consumption and to improve comfort and exhibition quality.

This article presents a technique for the design of slat-type blinds based on the their relative light intensity distribution under a uniform light source. The technique offers a new approach using a genetic algorithm in order to evolve the design according to a set of parameters. © 2005 Elsevier Ltd. All rights reserved.

The aim of this paper is to present the architecture, the algorithms and the performance results of an integrated indoor environment energy management system (IEEMS) for buildings. The buildings' users comfort requirements are fulfilled and regulated using a fuzzy controller. The fuzzy controller's structure is adjusted to the users' requirements that are monitored via a smart card system. The IEEMS is installed in two buildings in Athens and in Crete, both in Greece. The energy conservation achieved by the IEEMS operation is more than 30% compared to the existing control system. © 2004 Elsevier B.V. All rights reserved.

The present paper aims to examine the application of night ventilation techniques to 10 urban canyons, situated in the extended region of Athens, Greece. As the climatic conditions in the urban environment frequently present important variation in different locations of the same urban area, the outdoor air temperature and the wind profile have been measured inside and outside the experimental canyons. The present work determines the impact of the urban environment on night ventilation energy performance, by studying a typical room located in the urban domain, under air-conditioned and free-floating operation, when single-sided and cross-ventilation are considered, during the night period. The influence of the urban microclimate on the efficiency of the technique has been examined by considering the typical zone inside the canyons and under undistributed conditions. The comparison of the results permits to evaluate the impact of the urban environment on the effectiveness of night ventilation techniques. The performed analysis shows that due to the increase in air temperature and the decrease in wind velocity inside the canyons, the efficiency of the studied techniques is significantly reduced compared with the situation that considers the undistributed conditions, dominating outside the urban canyons. © 2004 Elsevier B.V. All rights reserved.

The connection of buildings to the Internet broadband network is becoming commonplace. The establishment of such an infrastructure enables the development of a range of new energy, environment and health-related services for people in their homes and workplaces. Telecommunications companies and utilities are actively developing examples of such services, and local authorities and health care providers are supporting trial deployments. Several of the services can be enabled or enhanced through the application of building modelling and simulation. This paper describes the infrastructure for the e-services under test within a European research project and shows the potential for simulation support for these services. © 2004 Elsevier B.V. All rights reserved.

The rapidly developing Internet broadband network offers new opportunities for deploying a range of energy, environment and health-related services for people in their homes and workplaces. Several of these services can be enabled or enhanced through the application of building simulation. This paper describes the infrastructure for e-services under test within a European research project and shows the potential for simulation support for these services.

Proper design and performance prediction of solar energy systems requires accurate information on the availability of solar radiation. The diffuse-to-total radiation correlation, originally developed by Liu and Jordan, has been extensively used as the technique and provided excellent results, although it was latitude dependent and not universally applicable. Thus, diffuse fraction correlations of this type have been developed by few other authors and for different location. This paper presents an analysis of hourly diffuse radiation on a horizontal surface. Hourly pyranometer data from Athens, Greece, are used to establish relationships between the diffuse fraction and the clearness index kT for hourly and daily values. The results of the proposed equations are then compared with earlier equations. For the urban conditions of Athens the developed correlation fit to the empirical data. © 2003 Taylor & Francis Ltd.

An average monthly variable, called the Obstruction Illuminance Multiplier (OIM), defined as the ratio of the illuminance received on a vertical surface due to light received from the sky, ground and the obstruction to the illuminance on the same surface without the presence of the obstruction, is proposed as a simple tool to investigate the potential of perfectly diffuse vertical south-oriented facades to reflect daylight onto the opposing facades. © Elsevier Science Ltd.

The present paper aims to investigate, in a systematic way, and by using both experimental and theoretical tools, the potential of night ventilation techniques when applied to full scale buildings, under different structure, design, ventilation, and climatic characteristics. Also, to investigate the impact and the limitations of night ventilation techniques regarding the thermal behavior of various types of buildings. Real scale measurements in three buildings operating under free-floating and air conditioning conditions have been performed. The cooling potential of night ventilation techniques applied to buildings operating under different conditions and with variable air flow rates, has been experimentally and theoretically studied. Additionally, sensitivity analysis on the impact of the major parameters determining the phenomena has also been carried out. Practical considerations on the impact of main parameters are given. © 1999 Elsevier Science S.A. All rights reserved.

Summarization: The building sector constitutes approximately the 40% of the total energy consumption in EU. TheDirective 2002/91/EC provides a precise legislative framework for improving the energy performanceof the built environment. [1]It was adopted on December 2002 and entered into force in January 2003. According to the article 15of this Directive all member states have a time period of three years (till January 2006) to implementthe Directive in their own countries. Till today all member states have already or will, in the near future,bring into force relative laws, regulations and administrative provisions necessary to comply with thisDirective.In this paper an innovative tool concerning the training of European citizens in the implementation ofthe Directive 2002/91/EC (Energy Performance of Buildings Directive - EPBD), that targets to reducethe buildings energy consumption and its efficient use in relation with the protection of theenvironment is presented. Additionally, certain features of this tool that depend on the existinglegislation and restrictions in each country and certain characteristics of the trainees (e.g. profession,scientific background) that influence in a great or in a small extent the training procedure in each caseare analyzed. Παρουσιάστηκε στο: 4th International Conference on Energy Performance and Indoor Climate in Buildings

Μη διαθέσιμη περίληψη Not available summarization Παρουσιάστηκε στο: International Workshop on Energy Performance and Environmental Quality of Buildings