Reports on the metabolic CO2 method for ventilation measurement which has been extended from mechanically ventilated rooms to naturally ventilated ones. The analysis, which under some circumstances is also relevant to tracer gas decay measurements, allows assessments of the individual incoming flows of air.
Uses a similitude approach to develop predictive graphs for the ventilation rate due to the stack or chimney effect. Uses a half scale model of an open side wall structure with a continuous and restricted open ridge, and finds that:< 1. Ventilation rate is approximately proportional to ridge outlet width< 2. Outlet Reynolds number response ie ventilation rate to changes in Grashof number is a function of the ratio between building height and ridge width.
The results of a prediction method for calculating ventilation rates in a detached house are compared with experimental measurements described in aprevious paper. The method is capable of giving good agreement for a wide range of ventilation conditions. The need is demonstrated for further work in two important areas - the spatial distribution of background areas and the effect of turbulence.
A combination of a wind-tunnel investigation and a mathematical simulation technique conducted on models of two-storey parking garage situated beneath alarge block of buildings (consisting of houses, shopping centre and offices) shows that wind penetrating the partly open garage facades can provide sufficient ventilation. Studies the effects on ventilation of varying the open area of the facades and of fitting openings in the garage roofs. Measures the effect of such ventilation means on air quality close to buildings.
Gives a brief survey of aspects of research into air infiltration. Discusses methods of measurement of ventilation rates and of building leakiness, covering the infrasonic and pressurisation methods of leakage testing, and thermography and tracer gas methods of measuring ventilation rates. Describes the available techniques for predicting leakiness and infiltration rates, and discusses their ease of application and accuracy. Concludes that the achievements of research to date are sound methods of measuring leakiness and infiltration rates.
TNO Research Institute for Environmental Hygiene have developed a mathematical model (based on an electrical analogue model) for deciding on the best ventilation system (natural v. mechanical) for a building while it is still atthe design stage. This model has been applied to an auction complex situated at Bleiwijk to deduce the best ventilation system for the building. Conclusions are that a natural ventilation system can be realized by placing ventilating devices exclusively in the roof.
Investigations in Denmark show that there are as many as 75 different compounds in indoor air in tight houses including toluene, xylene, and radon. The dust in homes contains a large number of allergically active ingredients, the most important being the dust mite, which occurs in bed clothes.< States that good air quality is therefore difficult to maintain with natural ventilation in new tight houses. If the hygienic demands of this decade increase the need for ventilation, mechanical ventilation seems to stand a good chance.
Characteristics of the ventilation in poultry buildings have been studied at the Hungarian Institute for Building Science. The pressure loss of the cross-building ventilation flow is determined for a section of a typical building and for two typical air inlet-outlet layouts. On the basis of velocity measurements the local hourly air change rates were determined in the cages and compared to the general air change rate in the building.