In line with its work on the positioning of gas air-conditioning systems in the commercial sector, the Gaz de France Research and Development Division conducted both experimental and theoretical studies. An air-conditioning system, known as the 'reference solution", was installed and equipped in a building on Division premises. The purpose of the system modelling and simulation study was above all to analyse the building's behavior regarding various criteria, while a technico-economic study compared the various (Generation systems.

This study presents a new method of interior air motion assessment using artificial neural networks. The air motion inside a building depends not only on the external wind velocity, but also to a great extent on most of architectural parameters such as position and orientation of building, size and configuration of windows, roof geometry, whether the building is stilted or not, etc ..

The design of natural ventilation devices in industrial buildings is complicated by the nonlinear interaction between the air flow rate and the indoor air temperature. Designs are therefore usually based on relatively simple calculations of the areas of ventilation openings to provide a specified flow rate at a given indoor/outdoor air temperature difference. However, the practical performance testing required for acceptance of the ventilator design still remains a difficult and dubious task.

This paper is describing the preliminary results of the Annex 27 work aiming at developing simplified tools for evaluating domestic ventilation systems. In this paper is given the tool to evaluate a system's ability to deal with different indoor air quality (IAQ) matters. In the work is used sophisticated simulation programs studying pollutant concentration either for each person or in an individual room. The evaluation is to be applied on houses that mainly are heated. This means that the tools are restricted to the heating season.

This paper presents a study of the dynamics of the turbulent mixing of a hot or cold air stream with the air in the interior of a building zone. Observations and CFO results of transient temperature behaviour in a fully developed jet flow field are presented. A simple model for the characteristic time-constant of the mixing process in a room is derived. The mixing of a turbulent jet, as a function of position inside the room, is also discussed. This mixing time-constant plays an important role in total system dynamic behaviour and stability.

In Amstelveen, The Netherlands, an apartment complex of forty two units has been build. Sixteen units are extreme low energy apartments. These apartments are very well isolated and have air tight facades.

Indoor air flow induced by a fan-coil unit in an air-conditioned environmental chamber is studied experimentally. The supply Archimedes number which is a macroscopic number describing indoor air flow is measured and related to the
centreline velocity and temperature decay of the cold air jet issued from the fan-coil unit. The space air diffusion and the thermal comfort using respectively the Air Diffusion Performance Index (ADP]) and the Predicted Percentage of  dissatisfied (PPD) are evaluated. Evolution of these indices with the supply Archimedes number is discussed.

When talking about air-conditioning systems in buildings people argue with high energy consumption of those systems. They do not take into account that it is not possible in many climates to realise several indoor thermal conditions by merely opening windows.Within the framework of the research project SANIREV, sponsored by BMBF and ROM, the Hermann-Rietschel-lnstitute make tests about the use of window ventilation. For different roomloads and out-door-conditions the room conditions are determined. Now we got the first results.