modelling

As measurements are essential for performance assessment, models are essential for design. Both empirical and rational models are being developed for predicting the effectiveness of ventilation for acceptable indoor air quality. In this status report, models for contaminant generation rates, and dilution and removal control are introduced through a simple, one-compartment model.

Ventilation studies using small-scale water models have, especially in Norway gained new and important knowledge in industrial ventilation the last 15 years. The outcome has been twofold. First of all it has resulted inimportant experience

Experimental methods have been developed to determine rates of air renewal. Based essentially on the use of a tracer gas, these methods permit the determination of real values on the site of the building itself. The pressurisation method which e

Air management in residential or tertiary usage buildings constitutes one of the key points of energy control in buildings. The principle themes concerning air management are heating or air conditioning, and ventilation and air renewal, mechani

Although there has been an increasing use of wind-tunnel tests on models to examine the structure of wind around buildings, there has been surprisingly little research into the correlation between the results of such studies andthe wind pattern around the full scale structures. This report gives the results of a comparison between the wind flow about a relatively open area of the city of Liverpool, as measured by the relative exposures of twelve field anemometers, and the flow observed in a 1:500 scale model of the same area immersed in a profiled, turbulent, wind tunnel flow.

The adiabatic boundary layer appropriate to flow over an idealised urban terrain has been simulated using a modified version of the system previously used to produce a rural boundary layer simulation. Where possible, measurements in the simulated flow were compared with full-scale measurements and reasonable agreement was obtained. However, because of a general lack of measurements in urban areas, several assumptions had to be made concerning the characteristics of some of the flow properties.

A wind tunnel of open-circuit configuration designed specifically for building aerodynamics is described and its performance is discussed. It has a working section 2 m wide x 1 m high x 8 m long with a maximum wind speed of 20 m/sec under

Notes that the trend to airtight window constructions has upset the balance in buildings between moisture generation and its removal. Treats the factors which combine to determine whether a building will have moisture problems. Presents a procedure for the straightforward determination of the specific minimum air flow required in a particular building to prevent condensation on the inner surface of corners formed by two dimensional external walls. Determines the base air flow and the supplementary air flow for four models of representative apartments.

Undertakes a comparison of full scale and model scale internal velocities of naturally ventilated rooms. The FSEC Passive Cooling Lab, an experimental building with a fixed roof supported by columns, whose floor plan and ceilings are reconfigurable, located at Cape Canaveral in Florida, is the building used in this study. The full scale tests were conducted during evening and early night to provide an almost thermally neutral atmosphere, during February and March 1982.

Reviews the literature on wind tunnel modelling of natural ventilation. Lists advantages of using wind tunnels. Discusses strategies for utilizing natural ventilation. Describes the mean windspeed coefficient method and the wind discharge coefficient method of estimating natural ventilation for design of buildings in hot climates, and gives their advantages and disadvantages. Gives criteria for constructing wind tunnel models.