English

Considers the characteristics of flow through small gaps. Discusses relation between wind tunnel measurements and actual wind pressure on buildings and the effect of building shape on ventilation. Derives equations for flow rate through a gap for different temperature and pressure differences and sizes of gap. The equations consider the pressure as a function of time thus modelling the effects of a turbulent wind incident on a gap.

Presents a simple model for the calculation of wind induced ventilation. The model requires as input, pressure coefficient data, wind direction, and the open areas for each element of the building. Gives an example of the model applied to a model livestock building. Gives flow chart and listing of computer program. Note model does not include temperature effects.

Discusses the mechanisms of natural ventilation. Gives equations for stack effect and ventilation due to wind. Discusses use of natural ventilation in livestock buildings. Shows how minimum and maximum ventilation rates for winter housed cattle can be calculated using physiological data and a model for calculating the critical temperatures. Gives sample calculation of the ventilation rate necessary for beef cattle housed in a 9m. wide building.

The open ridge is a ventilator commonly used in cattle buildings. Reviews literature on the open ridge. Finds that there is outright disagreement between the sources referenced. Describes wind tunnel study to show whether or not the ridge design could influence the pressure coefficients when subject to wind. Finds there is no practical difference in pressure coefficients generated at the ridge of a building whether there are no upstands, upstands alone or with caps. For a 0deg.

Measurements have been made of the air-leakage rates through structural components of conventional metal-panel and concrete buildings which may serve as containment for nuclear reactors. The component measurements included structural penetrations such as doors and louvers as well as materials such as caulking compounds, gaskets, and paints. Specimens were sealed inside of test vessels.

Reports methods used to measure the concentrations of Rn, Tn, and their decay products indoors and outdoors. Radon and Thoron concentrations are detected continuously by collecting the positively charged RaA and ThA atoms on a surface-barrier detector using electric field precipitation.< The concentrations of Radon and Thoron decay products were determined by collecting them on a membrane filter and simultaneously counting the activities by means of a collimated surface-barrier detector.Indoor and outdoor concentrations are measured simultaneously under different ventilation rates.

Reports tests of a scintillation counter to detect Ra 222 in air and water. The counter consists of a spherical cavity coated with ZnS(Ag) powder, built in a lucite cylinder whose external surfaces, excepting the window which is put in contact with a photomultiplier, are made reflective with a special paint. The performance of the detector has been analysed with respect to size,efficiency, background, constant activity and constant concentration in the sample. Finds that for liquid samples, two different values for the diameter, 5 cm. and 7.5 cm.

Reports study of the emanating power of radon from building materials. Samples of material were placed in an air-tight glass container and the radon diffusing from the sample was measured in an electrostatically operated cylindrical steel chamber in which alpha particle scintillations were counted.< Gives main results for different building materials in the form of anemanation coefficient, defined as the ratio of migrating 222Rn to the 226Ra content in the sample. Materials tested were fly-ash, slag, by-product gypsum, red brick, silicon brick, portland cement, and soil.

Reports a program of research in progress at the Colorado State University to determine the surface pressures on building models immersed in a simulated atmospheric flow. Pressure data on a model building is taken from 272 tappings and reduced to pressure coefficients. Reports pressure coefficient measurements have been completed for 23 building/boundary layer combinations.

Reports measurements of Radon-222 concentrations, carried out in the living rooms of 81 dwellings in Great Britain in 1976. Measurements of the activity concentration of RaA both within the room, and of the ventilation rate for the room were made. From this an estimate of the "radon output" of the room was calculated. Gives histogram of the radon outputs in picocuries of radon 222 per litre of room air per hour. Disregarding a very high measurement in a granite dwelling, the mean was 0.54 pCi/l/h.