English

There are two main soil gases of current concern to human health. These are radon, which is a carcinogen, and landfill gas, which is explosive and toxic. Both can be found at significant levels in the soil below buildings in certain locations in the country. It is a responsibility of the Building Research Establishment to find cost effective ways to protect new and existing buildings from the entry of these gases into buildings.

A three-dimensional drift-flux model for particle movements in turbulent airflows in buildings is presented. The interaction between the carrier air and the particles has been treated as a one-way coupling, assuming the effect of particles on air turbulence is negligible due to low solid loadings and comparatively small particle settling velocities. Turbulence effects are modelled with a standard K-E model. Wall functions are applied at near-wall grid points. Aerosol measurements carried out under turbulent room flow conditions are used to validate the numerical calculations.

Airflow behavior inside a cleanroom with vertical unidirectional flow has been investigated. The design parameters, such as porosity and height of raised floor, width of clean room and inlet velocity profile, which affect the uniformity of air velocity distribution inside the cleanroom have been studied computationally. The Reynolds-averaged Navier-Stokes equations governing the flow are solved using a finite-volume code ST AR-CD. The standard k-e turbulence model has been used.

The purpose of this study was to correlate building envelope performance problems which are currently being experienced in low rise wood frame residential buildings in the coastal climate of the BC Lower Mainland, with sources of moisture, and design and construction features. This study has facilitated the identification of key aspects of the design, construction, operations and maintenance processes leading to the problems, which in tum provides the construction industry with focal points for the development of solutions to the current problems.