Istis normally assumed by designers that all pollutants in a displacement ventilation system follow the buoyant air flow into an upper zone, where they are evacuated. But studies have shown that it is not always true and that concentrations of pollutant particles can be found in the breathing zone. This study aims at designing a ventilation system that will minimize the respirable airborne particle in that breathing zone.

This paper is the investigation of two approaches for describing the details of air-flow in large indoor spaces. One approach is the zonal method, and the second one uses a CFD model.Results swow that when airflows details are necessary, coarse-grid CFD is a better method for predicting airflow in large indoor spaces than the zonal methods.

This paper is a review and an exploration of the literature on indoor air quality in schools and the reported health problems related to it.The aim of that review was to identify health symptoms the most commonly reported in schools ;then to sum-up the existing measurement data on ventilation rate, CO2 concentrations and VOCs and biological contaminants in schools ; then sto um-up the information that exists on causal relationship between pollutant exposures and health symptoms in shools.

The European interdisciplinary group of researchers have reviewed 70 papers and selected 8 studies for their final review. From most studies, no definite conclusions could have been drawn concerning the association between particles matter concentration and health outcomes.
So giving limit values or guidelines for particulate mass or number concentrations in non-industrial indoor environment is not an adequate scientific evidence.

For that study, computer simulations and calculations of outdoor airflow rates and indoor air quality were made in parallel with site measurements in two Shanga office buildings equipped with typical Variable Air Volume systems.In addition to those site measurements, electrical consumption was recorded. Simulations and calculations of the electrical consumption and energy cost were performed.The site recorded data and the simulations results have been then compared and analyzed.

Turbine ventilator is an equipment that uses natural wind force to exhaust airflow ; such ventilators are widely installed in Taiwan to enhance building and factories ventilation. In theory, the combination of turbine ventilator with natural ventilation improves the indoor air quality while it decreases the reliance on air-conditioning. So that allows a reduction of the energy consumption.A variety of tests on different types of ventilators was conducted. The results proved it is helpful to increase ventilation with the installation of ventilators.

Temperatures in buildings with low and high thermal mass levels have been monitored during the warm period in Kenya. The effect of thermal mass in lowering the maximum indoor daytime temperatures has been evaluated as very effective.

For the study of single-sided natural ventilation, a CFD model along with analytical and empirical models have been used, to determine the effects of buoyancy, wind, or their combination on ventilation rates and indoor conditions.

This paper presents a case study : under extremely hot and arid climate, the thermal perception of 36 students has been tested. For the calculations, energy balance models of Fanger and Gagge et al. were used. There was a discrepancy between the observed and calculated values during daytime under extremely hot conditions.

The new model of the COMIS program has been modified, it allows individual rooms to be divided into smaller zones. This new program has been evaluated and the results have been compared to those from other zonal and CFD models.