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.

A two-dimensional turbulence k-e model is used to predict distribution of air velocity, temperature and turbulence kinetic energy in an air-conditioned room using ceiling air supply. Mixing characteristics of the airflow are analyzed under different air supply velocities and temperatures. A modified Archimedes number is correlated with the parameter ·characterizing heat transfer, ventilation system, and turbulence kinetic energy of room air flow. Significant correlations have been shown.

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.

This paper describes the measured and calculated results of airflow rates and pollutant concentration profiles in an airtight test house, the aim being to evaluate the calculation model COMIS for multizone air infiltration and pollutant transport. Firstly, the leakage areas of internal doors, exterior walls and windows were measured by the fan pressurization method. Secondly, two measurements were carried out, assuming that the test house consisted of ten zones.

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.

The pressure field in fluid systems reflects the flow configuration. Measurements of the pressure along the perimeter of a slot ventilated room have been conducted for different room sizes. The momentum of the jet at the end of the room is decreased with increasing room length. The impingement region (region where the influence of the opposing wall is present) starts, independent of room size, when the distance from the supply device is about 70% of the room length. Corner flows could not be predicted by CFD using the linear eddy viscosity or standard stress models. However.

The performance of a heat-pipe heat recovery unit was tested in a two-zone chamber with a horizontal partition. Air velocity was found to have a significant effect on the effectiveness of heat recovery. The effectiveness decreased with increasing air velocity. Simulation of air flow was carried out for the test chamber under natural ventilation conditions. It was shown that a heat-pipe heat exchanger can be used to reclaim exhaust heat in naturally ventilated buildings to effect energy conservation.