In the present study the relation between the wind speed and the air temperature during the summer period over the greater area of Athens is examined. Specifically, the hourly data of the air temperatures, recorded by 27 stations,were studied for the months of June, July, August and September during the period from 1996 until 1998, in relation to the corresponding mean hourly values of the wind speed which were measured by the National Observatory of Athens. As a result, a low increasing rate of air temperature in correlation to the wind speed exists during the day and night, time period.

It has been investigated the effect of different construction parameters to the thermal performance of a solar chimney.These parameters are the thermal resistance of the walls, the glazing type and the solar chimneys thickness.The thermal performance of the solar chimney has been studied using up to date thermal dynamic simulation tools.

The objective of this research consists of studying the effectiveness of devices used in the microbiological purification of the air. This specifically involves the inactivationof biological aerosols in an air handling unit. The study of a first device working on the principle of photocatalysis has been carried out. This system, called NEO developed by the CIAT Company (patent WO 2004/081458), involves the combination of filtration on an adsorbent and heterogeneous photocatalysis.The air cleaning device in question is installed in a test box located in a wind tunnel called ONE-PASS.

Multi zone computer simulation is used to predict the concentrations of carbon dioxide, carbon monoxide, formaldehyde and water vapour in a flat and detached house, fitted with five different ventilation systems all of which comply with current building regulations for England and Wales. Results show that, understandably, the different ventilation systems produce different spatial and temporal pollutant concentrations. A method based on equivalent ventilation rates for each pollutant is used to optimise the specification of the ventilation systems.

More than 8.000 homes have been built to the Passivhausstandard in central Europe. The success of Passivhaus is due in large measure to it being a well defined product, understood by the developer, architect and future owner. However the Passivhaus standard was born to respond to the requirements of a relatively cold region. The EIE funded Passive-On project has examinedwhat elements of the standard could be useful in promoting the diffusion of low energy house design in southern Europe.

In Heerlen, the Netherlands, warm and cold water volumesfrom abandoned mines will be used for heating and cooling of buildings, based on a low exergy energy infrastructure. The combination of low temperature heating and cooling emission systems, advanced ventilationtechnologies and integrated design of buildings and building services provide an excellent thermal comfortand improved indoor air quality during 365 days/year, combined with a CO2 reduction of 50% in comparisonwith a traditional solution.

The present paper describes the beginning of a sustainablerequalification program devised for some buildingsof the University of Brasilia, located in the city of Brasilia (latitude 15o south). The Requalification comprehends actions for implementing of old functions with reutilization of the existing building and landscape patrimony, a change in the patterns of consumption, an improvement in energy efficiency and a concern with the alternatives for optimum use of the spaces.

The paper deals with applicability of passive and low energy cooling technologies in the Czech Republic.In the paper there are presented two recent studies, where computer simulation helps to design properly the passive and low energy cooling for buildings is the Czech Republic. There is presented case studies applying,night cooling, thermal mass and slab cooling. The role of computer simulation in the low energy building design and optimalization is discussed.

In this article, the first part of a research project about the modelling of a solar chimney is presented. In this first part, the average ventilation flows measured in an experimentalinstallation have been compared to the results obtained by CFD (Computational Fluid Dynamics) simulations.In order to do so, a solar chimney with a cross-section of 0.78 m x 0.156 m, height 3.6 m, has been constructed.The chimney consists of a glass surface oriented towardsthe south.

The wind-induced natural ventilation of atrium buildingswith two roof openings has been investigated using computational fluid dynamics (CFD) techniques.