Describes a comprehensive investigation undertaken to determine the wind pressures on surfaces of models of typical low-rise buildings. For many practical applications building surfaces like facade coverings or tiled roofs are permeable. For those coverings the pressure equilibration across thepermeable surface is important when determining the net windload. Gives a survey of the physical parameters influencing the windload of permeable surface coverings. Presents results of a continuing study of the wind load on permeable facade coverings.
Tests a large office building, consisting of several octagonal towers and other blocks in a boundary layer wind tunnel. Determines the highest suction pressures which are relevant for the fixing of the cladding. Uses a tracer gas method to determine recirculation problems of the ventilation system inlets and outlets resulting from the arrangement of octagonal towers of different heights. Wind velocities on the flat roof of some towers are studied by meansof an erosion technique using flour, checks the accuracy of the method using hot wire measurements.
Uses model buildings to study external distribution of wind pressure and internal air flow. Compares air flow data with computed values derived from the pressure distribution data. Collects the pressure data obtained in a comprehensive study of wind loads on low-rise buildings and rearranges it in a form more suited to the computation of internal flows. Presents and discusses the methods emloyed in the reformulation and the results obtained. Briefly describes the development of design aids from which flow estimates could be made by simple hand calculations.
Performs tracer gas measurements and fan pressurization experiments on an 8-storied student residential building in order to determine the influence of wind as well as of stack effect upon air infiltration. Compares pressure and tracer gas distributions with those from a predictive infiltration computer model for high rise buildings.
Determines ventilation rates and intercell flow rates in naturally ventilated office building using multiple tracer gases. Subdivides the building into 3zones and seeds each zone individually with a different tracer gas. Monitors the time histories of the concentrations of all gases in each zone using non-dispersive infra red gas analysers. Calculates air flow rates from experimental data.
Compares and contrasts different methods of ventilation measurement in large buildings. Conventional methods of using tracer gas to measure ventilation rates in large volumes are cumbersome and expensive. These constant concentration and decay measurements require artificial mixing, complex monitoring equipment and large installation costs. By using discrete injection and sampling units, long term samples of tracer gas be collected with the minimum of capital and installation costs. Samples collected represent the mean local equilibrium tracer gas concentrations.
States that methods used by Swiss energy consultants in calculating air change rates are often inaccurate. Most consultants use the "observation method" utilising smoke pencils etc. and mistakes are made in calculating conditions causing air infiltration. Describes a new graphic method for estimating mean air change rates, which needs data on construction, pressurization values and window opening.
Reviews the published data on component air leakage, and from this compiles a set of component leakage figures for use in estimating leakage areas and their distribution in buildings. These calculations are compared with measurements of leakage areas in 36 houses in different locations in the US. The model predicts leakage area accurately for the average of the 36 houses, while for individual houses the standard deviation is about 20%. Discusses the assumptions and methods to convert other types of component leakage data to component leakage area.
Describes the retrofitting of a 14-storey office block in Oslo, done as part of an energy conservation project carried out in Norway 1979-82. The main reduction in energy consumption was achieved by tightening air leaks between concrete wall elements and windows by the application of sealing compound in 2 critical types of joint in the facade. Measures the energy consumption one year before and one year after retrofitting, using thermography to find the air leaks and to verify the tightening afterwards. Also carries out pressurization tests using the building's ventilation system.
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