Discusses how important it is to understand how the exhaust fan, stack discharge and replacement air contribute to a successful kitchen exhaust system.

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.

States that 80% or more of infiltration is due to the many imperfections designed into the building envelopes. Discusses the problem and the role of ANSI/ASHRAE Standard 62-1999.

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.

Describes the application of the HERS BESTEST system to a building energy simulation computer program. There was good agreement between the simulation computer program predictions and those of the reference programs. Different simulation inputs can be the cause of major differences between program predictions. The authors recommended that the HERS BESTEST manual be modified to include detailed information about the house models used to generate the results with the reference software tools.

Included in applications of multizone airflow and contaminant dispersion models to specific buildings are air quality diagnosis, weatherization, smoke control, and pressure balancing for laboratory hood safety. States that uncertainties in model inputs mean that the benefits of these applications are not being fully realized. Emphasises the need for an economical test method that is as accurate but less intrusive and faster than incremental or component-by-component blower door testing.

Describes a study carried out to validate multizone airflow and contaminant migration simulation programs as they apply to the modelling of tall buildings. Tracer gas experiments were performed in a building on a university campus. A comparison was performed between the measured tracer gas concentrations from these tests and those predicted by a simulation program.

Empirical validation studies of the application of multizone indoor air quality models to residential-scale buildings are reviewed here. The focus is on empirical verification efforts. Models have also been subjected to analytical verification and inter-model comparisons. Not many of the empirical verifications reported statistical analyses of the comparison between measurements and predictions. Additional statistical analyses have been performed and reported if sufficient data were available in the literature. Measurement uncertainty was not dealt with in most of the published reports.