prediction

Air movement within enclosures, which may result from a combination of infiltration, mechanical ventilation and convective heat transfer effects, is important for considerations of thermal comfort, ventilation efficiency and energy conservation.

A single whole building pressurisation test using robust and easy to use equipment can, in a very short time, quantify the air-leakiness of the building envelope. However, such measurements do not give a direct measure of the ventilation characteristics of the building which normally requires timeconsuming and specialist tracer gas tests. This paper provides a model which makes the link between leakage measurements and ventilation characteristics and applies it to a large, industrial building constructed according to 1979 UK Building Regulations.

This paper treats the structure of models for predicting interzonal airflow and contaminant dispersal in buildings. It will discuss the mathematical structure of such models, the use of modem data structures, the application of structured program techniques and the use of object-oriented structures for the development of users interfaces and building description processes.

In order to reduce the convective flow which is the principal responsible for the high indoor 222Rn concentrations, several mitigation technics have been developed and used in many countries. Since they don't always respond as expected, there is a need of instruments helping in their design and their evaluation. This paper suggests the use of a numerical code, based on the finite difference method, for the evaluation of 222Rn mitigation strategies in dwellings, It is supposed that 222Rn transport from soil into a dwelling occurs mainly by pressure-driven air-flow.

The performance of ventilation provision in subfloor cavities is relevant to the fields of energy efficiency, condensation risk, and air quality. Thorough programs of site measurements of ventilation rates by means of tracer gas tests are in general protracted and expensive, and it is quite clear that would be highly desirable to be able to predict ventilation rates given details of building design, ventilation provision, and d.egree of exposure.

Large openings such as doorways or windows are privileged places through which a large amount of air, heat and pollutant species flows.  In order to predict air flow rates through these systems, a physical model which can be integrated to multizone air flow models is proposed. This model is based on the empiric determination  of discharge  coefficients. The discharge coefficients  may have different definition depending on the hypothesis of the selected model.