Natural ventilation of dwellings is commonly applied, especially in mild and moderate climates. The disadvantage of natural ventilation is the poor control of both flow directions and flow rates within the ventilated building. To improve control, theuse of mechanical exhaust is often recommended. Though this may improve total ventilation, the ventilation of separate rooms often is insufficient still.
Air Infiltration in Norwegian buildings has been an unknown parameter. This paper is based on results from measurements in nine different buildings in Norway. The measured parameters have been: infiltration envelope air humidity and temperatures on theinside and outside of the building. The infiltration has been measured continuously with tracer gas using the constant concentration method. In addition air tightness measurements and thermography have been carried out to establish the dimensions and the locations of the major leaks.
Because of the wide range of parameters (wind speed and direction, temperature difference, position and characteristics of flow paths, building shape and location) which determine natural ventilation, obtaining useful design information from field measurements presents many problems. This note provides an approach for analysing the results of field measurements of single-sided ventilation. The background to the measurements and associated theoretical and laboratory studies of possible physical mechanisms for single-sided ventilation are presented fully elsewhere.
The modern trend towards more airtight energy efficient housing requires additional care in providing controlled ventilation. Passive Stack Ventilation (PSV) is one way of providing the necessary control. The Building Research Establishment (BRE) is carrying out research into the performance of PSV systems in dwellings. Several different PSV systems were installed in a test house and the flow velocity through them measured under a range of meteorological conditions. The results of these tests are presented and the effect of bends in the duct and duct diameter are discussed.
There is considerable interest in possible designs for naturally ventilated Law Courts, which avoid the need for air conditioning. However, design requirements make it difficult to locate windows for ventilation purposes. A proposed alternative is based around the concept of providing summertime ventilation via an underfloor duct and controllable vents at roof level, under the action of wind and buoyancy forces alone.
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