A commercially available humidity controlled natural ventilation system (Aereco) has been installed in the framework of a CEC demonstration project in 3 apartment buildings in France, the Netherlands and in Belgium. An extensive monitoring campaign in reference apartments and humidity controlled apartments during the 2 previous winters allowed a detailed analysis of various ventilation related parameters. Special attention is given to the evaluation of the humidity control on the performances.

A passive tracer gas technique has been used in an experimental study of the distribution of contaminants in a room with displacement ventilation. Humans are simulated by heated metallic bodies and the tracer concentration in the breathing zone (exposure) is shown to be greatly influenced by both the position of the tracer source and the air convection current around the bodies. It is shown that pollutants emitted close to a body are completely and directly transported to the upper mixed zone and not mixed into the lower zone.

This paper illustrates the principles of demand controlled ventilation systems (DCV) as applied to office buildings. Appropriate ventilation approaches and control strategies are demonstrated in this paper for small area control (ieboardrooms) and for office buildings as a whole. Findings are illustrated by the results of field experiments. Impacts on energy consumption, indoor air quality and occupant response are examined. General conclusions and recommendations applicable to similar building types are also presented.

This paper is based on field measurements in auditoria which were carried out in Norway and in Switzerland. In both cases carbon dioxide (CO2) was chosen as the relevant indicator to establish ventilation demand.

"Air Movement and Ventilation Control within Buildings", held 24-27 September 1991, Ottawa, Canada, proceedings published September 1991, Volume 1, pp 141-142. #DATE 00:09:1991 in English",An overall presentation will be given of the final report from Annex 18 experts are proposing DCV-systems in various building types. The presentation will be focused on strategies and pre-requisites and on DCV-systems in the building types not presented separately.

Air is the main transport medium for contaminants in buildings. Minimizing source strengths has first priority, second is to control air flow rates, supply and exhaust, and directions between zones in buildings. Computer simulation models forventilation and pollutant spread in buildings have been proven to give useful predictions. Large measurement campaigns for optimizing ventilation and pollutant problems are complex and expensive. They are often jammed by too many vague parameters influencing the result. The computer models are an alternative and form a supplement to measurements.

Airflow through a building has both mean and fluctuating components due to spatial and temporal variations in wind-induced pressures. Most of the existing investigations consider the average values of wind pressures and predict steadystate solutions for airflow [1]. This paper presents some experimental results for the validation of a proposed fluctuating airflow model [2]. The new model employs spectral analysis and statistical linearization methods to model the pulsating airflow through buildings.

The subtask 2 of Annex XX (Optimization of Air Flow Patterns Within Buildings) involved a research project called "Air Flows Through Large Openings In Buildings". The scope of this project was to test the range of validity of available algorithms, and where possible to develop new ones. This paper focuses on the new interzonal airflow studies which have been carried out in this frame.

We report on four new full scale experiments that were designed to measure the influence of wind on the ventilation and/or heat loss rates through single large openings: a) test-house with horizontal slit opening, set-up to measure internal pressures and the effect of air-compressibility (CSTB, France), b) attic with window ajar, set-up to measure long term ventilation rates with varying wind and temperatures (BBRI, Belgium), c) fully open window, set-up to measure ventilation rate and cooling as a function of time (BRE, UK) d) fully open window, set-up tomeasure cooling as a function of ti

The paper describes work on simplified design methods made in connection with the International Energy Agency programme "Air Flow Pattern within Buildings", Annex 20, subtask 1. It is shown that simplified models are able to indicate design values as the maximum velocity in the occupied zone and penetration depth of a non-isothennal jet in a room. The design according to throw of an isothermal jet is a fully developed method which has a sufficient level of accuracy when it is used in regular rooms.