This paper attempts to provide a general basis for implementing the principles of pressure differentials to aid in providing more user friendly air quality in buildings. This is a new technology application to be added to the commonly used air changes and filtering for cleaner air. The success story of smoke control can now be used as a major strategy against pollution and disease control in buildings. Stale bacteria-infiltrated air can also be contained to its spaces of origin and exhausted from its sources in the building.
This paper presents results from a wider study into providing displacement ventilation in urban areas by taking air into buildings from the top without the use of fans. Results from large scale experimental work are given. These results indicate that ventilation airflows can be induced using gravity chillers and heaters in conditions where this type of installation would otherwise fail. The paper also describes initial experiments undertaken to see how far the same equipment can be used for heat recovery. One test installation was modelled using a proprietary zonal model.
Multizone modeling refers to analysis techniques that use a simplified, zonal representation of a building to study building airflows, pressure differences, and contaminant transport. Each zone is assumed to have uniform temperature, pressure, and contaminant concentrations. Zones typically represent individual rooms but can be entire levels depending on the building layout and the goals of the modeling. Zones are connected through flow paths represented mathematically by pressure-flow relationships. This article describes CONTAMW [Dols et al. 2000], a multizone modeling tool.
A three-dimensional numerical model is used for a turbulent buoyant jet. The standard k-E model has been modified to focus on the buoyancy-production term. The usual and modified buoyancy production coefficients are used for comparisons with experimental data reported in the literature. Imported numerical results are obtained with the modified coefficient for the stack-exit velocities and temperatures. The effects of these parameters on flow characteristics are discussed.
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