Local exhaust ventilation systems are normally the most cost efficient method for controlling air pollutants and excessive heat. For many manual operations, capturing pollutants at or near their source is the only way to insure compliance with threshold limit values in the workers breathing zone. Local exhaust ventilation optimize ventilation airflow thus optimizing system costs especially where recirculation is not used.

This paper discusses two complementary techniques for modeling human exposures to airborne contaminants with a focus on control decisions involving ventilation. Particular attention is given to: (I) the use of empirical-conceptual models with dimensional analysis and (2) computational fluid dynamic simulations. Both techniques provide valuable information. An empirical -conceptual model is formulated with dimensional analysis for a spray painting operation.

Describes the development of the Swedish duct tightness guidelines, the "AMA system". The latest version, due in 1998, aims to increase tightness requirements once again by introducing a tightness class D as the standard requirement for larger spiroduct systems. The concern about an increasing part of the Swedish population becoming allergic and asthmatic led to the Swedish Parliament introducing compulsory inspections of ventilation systems in 1990.

This paper describes the design and development of the natural ventilation system of the new Contact Theatre Complex Manchester, UK, designed by A Goldrick of Short Ford Associates. The ventilation design is based on a stack dominant system using an "H-Pot" chimney configuration. The paper describes the development of the ventilation design of both the studio theatre and main auditorium ventilation systems.

Temperature and cooling demand in a room summertime are influenced by numerous factors,like internal gains, ventilation, solar gain, behaviour of occupants, thermal inertia of the roomand outdoor conditions (climate).The thermal environment and cooling demand summertime are often analysed using detailedcomputer programs, which take into account the factors mentioned above (among others).Often the overview, transparency and some of the physical insight is lost using these advancedcomputer programs.In a predesign phase of a project it is preferable to do simple calculations of the thermalbeha