passive cooling

Primary energy consumption in Algeria continues to grow, and this is associated with the growth in sale on conventional air conditioning systems. This was a major impact on electricity demand specially for summer cooling purpose for north and south regions of Algeria. This investigation demonstrates that the combination of passively driven air movement and evaporative cooling through wind tower system can be used with success and fulfil comfort requirements of hotel accommodation under constantine climate.

This paper describes a European project to produce comprehensive design guidance on urban layout to ensure good access to solar gain, daylighting and passive cooling. The project involves:

The present study applies the N3S CFD code to the air cooling simulation on an "architectural reference object", namely the "Maison Ronde" of Mario Botta. The summer night situation is examined when natural ventilation creates indoor air motion and cools the building structure. The transient behavior of the walls is represented by a thermal model coupled with the CFD code. The simulation evaluates the unsteady temperatures of the outdoor and indoor air flow together with those of the wall surfaces.

This study is a contribution to European projects Pascool/Joule II and Altener/Sink that deal with the usability of passive cooling systems in Europe. The first phase of this work was to define design methodology in order to evaluate natural cooling potential according to the climatic quantification criteria of the site, the cooling needs of the building, the cooling system performances, and comfort criteria defined by the couple of temperature and relative humidity set points.

In summer, it is possible to achieve a satisfactory comfort in residential buildings with purely passive means as thermal inertia, possibility of cross ventilation and solar protection of the external envelope. These parameters have to be taken into account at the earliest stages of building design.

The present paper investigates the potential of night ventilation techniques when applied to full scale office buildings, under different structure, design, ventilation, and climatic characteristics. The approach of this study includes the use of both experimental data and theoretical tools in order to determine the impact and the limitations of night ventilation regarding the thermal behavior of various types of office buildings.

OFFICE is a research project partly funded by the CEC dealing with the passive retrofitting of office buildings to improve their energy performance and indoor working conditions. The project is coordinated by the University of Athens with the participation of organizations and research institutes from eight European countries. The aim of the project is to develop global retrofitting strategies, tools and design guidelines in order to promote successful and cost effective implementation of passive solar and energy efficient retrofitting measures to office buildings.

Comfort evaluations cover air quality, thermal, visual and acoustic comfort. Today, only few computer programs allow for the integrated evaluation of several or all relevant parameters. Heat transport, ventilation as well as lighting in a room are influenced by each other. Therefore they should be integrally modelled. As a part of the IEA-ECBCS Annex 23 'Multizone Airflow Modelling', such a coupling has been realised by integrating the air flow and contaminant transport simulation code of CoMIS into the building and systems simulation code TRNSYS.

In 1993, the Open University in Milton Keynes, UK, refurbished the open-plan first floor Design Studio in their Publishing Department to use natural ventilation to keep the interior cool. At the same time the third floor, which was not suitable for passive cooling, was fitted with mechanical comfort cooling units and the intermediate floor was not changed. This paper compares tl1e thermal performance of the three floors and discusses the results of a staff-satisfaction survey conducted among the occupants.

The role of metallic surfaces is not only to save energy in winter and in summer by separating the inside and the outside. New and inexpensive ways of collecting solar energy for internal heating, new ways of ventilating, heating and cooling through the fabric elements are described. Two very significant prospects are : radiative cooling by metallic surfaces and enhancement of indirect daylighting by optimised ceilings. The subject of the European CURES program is to promote these new technologies by simulating and testing them.