AIVC - Air Infiltration and Ventilation Centre

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air leakage

Air infiltration through gaps around windows

The amount of air leakage through window gaps in buildings depends on the width and length of the gaps, the pressures across the buildings and the resistances in the air circuit. Reviews the ranges of these factors for Britain and gives results of measurements within these ranges for standard metal and wooden windows and for weather-stripped windows. Gives two methods of estimating the air flow through gaps in complete windows.

Experimental study on air and water tightness of metal window sashes.

Describes apparatus and test method used for measuring air leakage through metal windows in the laboratory. Gives results for different types of windows and summarises air tightness standards in Japan and other countries.

Natural infiltration routes and their magnitude in houses part 2.

Describes a simple pressure method for measuring the air tightness of small buildings. It measures the leakage rate from all apertures in the external envelope simultaneously, from which total leakage area of openings could be inferred. Site measurements have shown that obvious sources of leakage like doors and windows account for only the minor part of total leakage area in the average dwelling. Results from 25 dwellings show no trend of leakage area per unit of gross floor area.

Rain and air leakage at joints

Known principles for the prevention of rain penetration and air leakage are not being applied in practice. States that rain penetration requires the simultaneous presence of water, openings and a force ; the two-stage weathertightening or "open rain screen" separates the control of these factors and allows the production of a weathertight joint under practical conditions. Outlines the causes of air infiltration and gives brief case histories to illustrate the serious problems that can arise from air leakage.

Why airtight houses? Varfor tata hus?

Explains why house external shell and ventilation system must be treated as integral elements of a total system. Explains, using an analogous water system, why air leakage through shell is greater using push-pull ventilation than when using extract ventilation and why houses should be airtight.

Air leakage through joints Luftlackage genom fogar.

Reports tests of air leakage made in the joints in a hospital building in gothenberg using a special pressure chamber. Describes test method and gives the values from five readings ina table. The required standard was that "the maximum leakage of air would be 300 litres per m run joint per hour at a pressure differential of 10mm of water". Tests showed that the required standard was met and perhaps that the amount of attention given by contractors and owners to joint problems has increased.

Draught or ventilation? Tjyvdrag eller ventilation?

Shows by comparison with simplified methods for dimensioning structural beams that the degree of tightness of a shell is not the arithmetic sum of the leakage of components. States that leakage occurs where there is a pressure difference caused by wind, temperature difference and fans. The amount of leakage depends on whether the air flow is laminar or turbulent. Gives equations for the calculation of leakage in buildings without ventilation, with natural ventilation, with mechanical evacuation and with both mechanical inlet and evacuation.

The repeatability and reproduceability of test results on windows and wall span elements and the expected results.

Discusses variations in the test results which occur with the laboratory procedures for assessing the air and water penetration attributes of windows. Presents data for windows examined under British Standard BS 4315 : part 1 "Methods of test for resistance to air and water penetration - windows and gasket glazing systems". Considers the implications of thesetests for the development of performance levels for use in standards and procurement documents, and proposes a two-stage statistical procedure, based in the first instance on tests on five windows.

Condensation between the panes of a double window

Discusses causes of condensation between the panes of a double window. Treats movement of water vapour by diffusion and by air leakage separately. Describes tests made to determine air flow and vapour diffusion through test windows finds that relative importance of the mechanisms depends largely on the inside to outside pressure difference so that the higher the pressure difference, the greater the importance of air leakage. Suggests venting of windows to overcome condensation.

Air leakage through various forms of building construction

Reports tests made to determine the air leakage characteristics of various types of walls. Describes apparatus and method and gives results of tests on brick, wood frame, stucco and brick and tile walls, with and without plaster, paint and caulking. Finds that air leakage characteristics alter with the age of the wall, that paint alone did not greatly reduce the leakage of the brick wall, but that plaster was very effective. Also gives data for leakage between plaster or stucco and wood frame.