This paper is not intended as an exhaustive account of all the available natural cooling techniques, including an interminable list of references, the advantages and disadvantages of each technique, and their field of application. Rather, it is intended to present the perspectives of future research and the topics that should be covered within the frame of a European concerted action. Thus, it will concentrate on the main obstacles and faults that we feel exist in the current research, and subsequently on the measures that should be taken to correct this.

The work in progress of an Expert system called ISOLDE that is being prepared in a specific Tusk of the International Energy Agency is presented. This program will give intelligent user support on energy use and thermal comfort during the design process of commercial buildings through general advices, simplified methods, detailed simulations. In particular the paper focuses on the passive cooling approach covered by this tool. 

This paper presents the state of the art on the natural cooling techniques. The development on the evaporative, radiative and earth contact cooling techniques and components is discussed. A classification of the existing systems and techniques is attempted and tbe knowledge on the more important of them is presented. Advantages and disadvantages of the classified systems are evaluated and their suitability for European climates is discussed. The luck of information as well as the existing scientific gaps on the subject are identified.

In France, air conditioning of offices is often required especially in areas with high noise levels and in the Mediterranean climates. Evaporative cooling systems appear able to give a cost effective solution to the growing demand for summer comfort: hence, the CSTB and Gaz de France are currently conducting a joint research on the efficiency of such systems. On the basis of a comfort criteria, this have been done by computer simulations taking into account different kinds of systems, buildings, and climatic areas.

Fast development of computer technology and the greater use of it in all spheres of activity have caused the development of software support in the field of HV AC systems. Considering the fact that today time is of great value and that contemporary technical systems demand economy and rationalisation of operating costs and energy, the qualitative and user-friendly computer-aided engineering is of maximum importance.