English

Describes an investigation of the possibility of using artificial neural networks to predict air pressure coefficients across openings in a lightweight single-sided naturally ventilated test room. The network was trained using experimental values. A monitoring experiments was carried out on the outside local temperature, wind velocity and direction. Estimates were made of the pressure coefficients at the top and bottom of the openings from the recorded data of air pressures and velocities across the openings with indoor air temperatures.

Describes a global approach to passive design of naturally ventilated buildings situated in the French overseas territories. This approach involves all those involved in the buildings creation process, including architect, owner, building physicists and climate engineers. A validated thermal and airflow building simulation software was used to assess the design and sizing. A reference document was created from the optimal technical specifications, and has been used to build over 800 new pilot homes.

There are important benefits to come from using passive techniques as opposed to artificial cooling. They may not be sufficient to provide thermal comfort throughout the year in wet tropical areas, however. Few experiments have been performed on the thermal performance of buildings using a mixed-running strategy in warm-humid climates. The paper attempts to demonstrate that a possible dual-mode integrated operation can be used for such locations.

The study aimed to identify the behaviour of wind in the type of urban blocks usually found in cities in tropical climates. The results presented here were obtained in colonial type areas. The authors' approach was to establish a relationship between the clusters of buildings and the evidence of overpressures or low-pressure in proximity to the openings of occupied spaces. A prominent physical feature of natural ventilation is the maximal difference of pressure between windward and leeward building facades.

Among significant occupational health problems are building-related health complaints and symptoms. A potential cause has been identified as the elevated concentrations of various types of indoor contaminants, which are frequently associated with inadequate ventilation. This research aimed to model and evaluate the performance of several ventilation methods on volatile organic compound (VOC) removal in indoor environments. The time history of the contaminant concentrations in a model office have been simulated using a newly developed computer model.

The study forms part of a research project performed by LEPTAB and ATMO Poitou-Charente within PRIMEQUAL program which targets the relation between the indoor and local outdoor pollution. According to many studies, outdoor pollution has a major influence on indoor air quality, airflow being the main factor linking the outdoor environment directly to the climate indoors. A precise regulation of the air flow entering the room is enabled by the mechanical ventilation system and this makes possible the control of the indoor air pollution concentration.

Interest in natural ventilation is growing in the USA. Potential benefits include lower energy costs, improved indoor environmental quality and greater occupant satisfaction. Describes the challenges presented by the implementation of natural ventilation strategies.

The environment inside museums such as the Field Museum of Natural History in Chicago, USA is of utmost importance since permanent damage can be caused to artifacts in the environment is not correctly maintained and controlled. The article describes a longitudinal environmental survey carried out to assess the performance of the facility's HVAC systems and controls. A series of hypotheses was developed and tested to explain deterioration of a number of mammal mounts in the museum's exhibition halls.

The use of two simplified models was demonstrated in this study, the box and momentum methods, in order to simulate complex diffusers in room airflow modelling by CFD. Additional flow information is needed by the two methods, which is not available from product catalogues of diffuser manufacturers - the information required includes the distribution of discharge air velocity, box size and flow direction. A test method was developed on how to obtain the additional information with minimal effort under ASHRAE standard 70-1991.

To validate the emergency operation modes of a 7 km long underground railway tunnel ventilation system, a full-scale experimental investigation has been performed. The results of the test showed that the tunnel ventilation system can successfully provide the critical air velocity necessary for a fire sized 13.6 MW. Alternatively, the large reservoir for smoke under the tunnel ceiling may give more time for escape and ought to be considered when planning for the emergency procedure. The system is now operating commercially.