A multizone air flows simulation code (IDA MAE) was used to evaluate a hybrid ventilation system (passive stack with assisting fans) in a Swedish school (9350 m2 - 20 classrooms), in the framework of the HYBVENT project (Annex 35 of IEA). Simulation was operated with 18 zones. Results show the sensitivity of air flows to changes in wind speed and direction.

Design process of buildings currently addresses indoor air quality through ventilation flow rates requirements. In some circumstances, this approach may be not sufficient and an alternative is to determine ventilation rates through contaminant-based design methods. The authors present several examples of such approach, especially using multizone modeling (CONTAMW model) in a two-story classroom/office building equipped with a CO2 demand-controlled ventilation.

Laboratory experiments were performed to evaluate the effect of different CO2-based demand-controlled ventilation strategies (on/off, proportional, linear, PID) on energy consumption and indoor air quality, with various ventilation rates and occupancy profiles, and with one- or two-zones controls. Results show the capability of different strategies to maintain acceptable indoor CO2 level with the minimum outdoor air requirement.

A specially designed garment for direct physical measurement of both the convective and the radiative components of human heat loss was developped, using sensitive heat flux transducers housed in clothing pockets. Investigation with a human subject showed the advantages and the precautions to be taken using this equipment.

A procedure to verify, validate and report CFD analyses in indoor environment applications has been developed. The process on how to use this procedure is explained through the example of CFD modeling of an office with mechanical displacement ventilation.

Ventilation airflow rates and internal air distribution were measured in four poultry slaughter plants (250 to 775 workers), equipped with negative pressure ventilation systems (exhaust flow rate from 7.1 to 27.4 m3/s - no air intakes - supply air entering through various openings). Results lead the authors to recommend the installation of diffusers for makeup air supply, changes in the organisation of rooms to avoid contamination of one by the other and regular maintenance and cleaning of ventilation components.

An audit of 20 hospital operating rooms was operated in Grece in order to collect information about the HVAC installations and the indoor physical parameters. Data were also collected from 560 medical personnel through a questionnaire about the assessment of the indoor conditions.

Tests have been performed on several ceiling air diffusers supplied with low air temperatures (6 to 16°C - 90% humidity) to study water vapour condensation on diffusers surface. Results show that a supply air temperature of 11°C avoids most of condensatio

The risk of contaminant deposition (10 microns particles) on an operating room surgical site is evaluated for different ventilation systems - conventional, laminar, non-aspirating, displacement -, using airflow modeling and particle tracking methodologies. Results show that laminar flows are the most appropriate to avoid particles deposition.

The paper gives an explanation of the phenomenon of attachment of a cold air jet to a ceiling, based on a theoretical analysis. A formula to calculate the distance between the blowing slot and the point where the cold air jet will separate from ceiling is given. The results of calculations using this formula show good agreement with experimental data.