This paper summarizes the results of an horizontal study on Passive and Hybrid Cooling for buildings, carried out by the authors, on behalf of the EEC Research Program "Building 2000" /1/. The state of the art of the strategies for the prevention of thermal gain is presented. Also the existing situation on the design tools and the computational methods regarding the Passive and Hybrid cooling techniques and components is analysed. Finally the data of several designed and constructed buildings in Europe using Passive and Hybrid cooling techniques and components are given and analysed.

Two models, the Eggenberger- Polya and the William's logarithmic series have been used to predict the probability of occurrence of varying length mild and hot spells, respectively, for the summer period using a 13-yr hourly database from Athens. Greece. The proposed models provide the necessary information to energy analysis and climatologists contributing towards a more precise analysis of the summer comfort conditions.

Environmental concerns such as ozone depletion and global warming are forcing the building design profession to explore new ways of space conditioning. This paper looks at a number of potential low energy cooling strategies, and using dynamic analysis techniques makes an assessment of the ability of such strategies to contribute to the cooling of buildings in the UK climate.

For exhaust systems that handle dusts, a minimum transport velocity is required to prevent settling and plugging of ductwork. The minimum transport velocity required was studied experimentally for different kinds of dusts. In the case of horizontal ducts, three different velocities related with the minimum transport velocity were measured: saltation velocity, settling velocity and pick up velocity. The experimental results obtained are shown in different graphs, plotting minimum transport velocities vs. particle size and density.