English

In 1987, workers in the kitchen of one of the teaching hospitals in Halifax, Nova Scotia began to experience symptoms of pruritus, folliculitis, wheezing, conjunctiva/ irritation, sore throat and headache, all suggestive of an indoor air quality (IAQ) problem. Approximately 127 of 160 kitchen workers were affected over a 2-year period and the complaints included cognitive difficulties and reactivity to environmental irritants.

When outdoor air is the main source of pollutants indoors, mechanical air ventilation can be viewed as having two fronts of action in controlling indoor air quality. The first is its capacity to remove indoor air pollutants by dilution, and the second is its capability to prevent, through its pressurisation effect, the pollutant source (i.e. untreated outdoor air) from infiltrating, through the building envelope, to the occupied space.

Acceptability of clean air and air polluted by building materials was studied in climate chambers with different levels of air temperature and humidity in the ranges 18-28°C and 30- 70% relative humidity (RH). The acceptability of the air quality immediately after entering a chamber and during the following 20-min whole-body exposure was assessed by 36 untrained subjects who maintained thermal neutrality by modifying their clothing.

Investigations of particle concentration levels and size distribution were conducted in the complex hospital system of the Royal Children's and the Royal Brisbane Hospitals in Queensland, Australia. The aim of the measurements was to provide an indication of particulate sources in the hospital environment and relate particle characteristics to the operating parameters of the hospitals. The measurements were performed using the most advanced instrumentation for size classification in the submicrometer and supermicrometer levels.

The calculation of airflows is of great importance for detailed building thermal simulation computer codes, these airflows most frequently constituting an important thermal coupling between the building and the outside on one hand, and the different thermal zones on the other. The driving effects of air movement, which are the wind and the thermal buoyancy, are briefly outlined and we look closely at their coupling in the case of buildings, by exploring the difficulties associated with large openings.

Computational fluid dynamics (CFO) was used in a study of the air flow characteristics in the occupied building zone. Correlation equations between the mean air speeds and the percentage dissatisfied with the macroscopic flow numbers were derived. Ten macroscopic flow numbers including the total ventilation rate, the air change rate, ventilation rate, air diffusion performance index, modified jet momentum number, two new flow numbers and three expressions of jet momentum ratio were investigated.