Although there are many simple infiltration models already available none of them have an appropriate method of dealing with what is often the single largest leak in a building; a furnace or fireplace flue. Flues are different from the distributed leakage used in simple in filtration models. Flues represent 10% to 30% of the total building leakage all of which is concentrated at one location above the ceiling height.
Leakage area measurement by fan pressurisation becomes more difficult as the volume of a building is increased. The equipment becomes bulky, and measurements of air flow through the fan and the resulting pressure differential require more care. AC pressurisation offers an attractive alternative. However, in the case of large industrial buildings, the exterior envelope is often constructed of thin flexible sheet material, and also industrial leakage paths may have a much larger area than is found in, say, typical domestic construction.
Air Infiltration in Norwegian buildings has been an unknown parameter. This paper is based on results from measurements in nine different buildings in Norway.
This investigation was performed to evaluate the effectiveness of detecting air leaks in typical constructions through the measurement of sound transmission. The sound transmission of various slits was measured. These were designed to simulate field constructions. Due to the fundamental difference between steady air-flow and sound propagation, it was concluded that the method fails, particularly in the case of foil-covered slits and slits coupled to damped cavities.
Wind pressure coefficients (Cp values) are among the basic data required for ventilation and air infiltration calculations and modelling. More than two years of systematic wind tunnel testing in ETI of some of the most frequent building shapes has resulted in a database that has been provided with a handling program. This package is available from ETI, for IBM XT/AT and compatible PC's.
In the field of ventilation engineering the understanding of jet types of flow is well established. However, the behaviour of buoyant flows with high initial Archimedes numbers has been much less explored. The aim of this short note is to highlight some of the differences between ordinary jet flow and the discharge from low velocity air terminals. Results are presented both from tests carried out in a full scale mock up and from model tests with water as operating fluid.
In this note we discuss the problem (concealed by the latter statement) of calculating the inside air temperature which varies with time and is, when not measured directly, in general not known. The inside air temperature (Tin), which is in betwe
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