Ventilation produced by fluctuating pressure differences across a building appears to have received little attention . Such fluctuations are produced by gustiness of the wind or turbulence in the flow around a building. An experimantal study has been performed on a laboratory model to investigate unsteady flows through apertures simulating those in the fabric of a building .
Outdoor air pollution can have a bearing on the effectiveness of indoor air and the quality of ventilation. There is a pressing need to reflect on the potential type and effect of occurrences (e.g. smog, or chemical accidents) and to develop technical, operational and organisational measures which must be taken with mechanical ventilation units in the case of polluted outdoor air situations. A polluted outdoor air situation is present when a ventilation process leads to the intake of pollutants in the interior and to the enrichment of these pollutants to an unacceptably high concentration.
An experimental study in reduced scale model for ventilation inside a sheep-fold has been studied. The ventilating system consist of two slots in opposite side walls and one in the roof, Two-dimensional jet are generated by the wind effect and temperature difference acting upon the sheep-fold.
Since thermal comfort on human body is influenced by the local air flow speed, it is needed to estimate the distribution of air flow speed in a room for the "effective ventilation". Numerical solution of the equations for the motion of 3-dimensional turbulent air flow and model experiments are conducted for this purpose. The experiment model is a single room model house with 2 windows on the opposite walls. It is actually ventilated by the natural wind. Non-directivity thermistor anemometers are used to measured the 3-dimensional distribution of indoor air flow speed.
This paper is concerned with natural air flows between major construction cavities in New Zealand houses. A two tracer technique was developed to measure infiltration rates in the subfloor (crawl space), the living space and roof space, together with air flow rates connecting these zones. Five experimental houses were chosen to represent expected extremes in air flow resistance between subfloor and roof space.
This paper reviews research activities undertaken in the framework of IEA Annex XIV, "Energy and Condensation". It outlines the objectives and working scheme. The importance of ventilation as an influencing factor and a remedial measure is investigated. The central theme of the IEA workshop, held in Leuven in September, 1985, was the problem of condensation.
This work deals with problems of the air humidity in inhabited dwellings. A new approach is presented here which renders the definite diagnosis of humidity problems possible. The room air humidity from two buildings with different air ventilation systems with eight dwellings each is examined, The efficiency of the different ventilation systems is presented applying the new value, the so called "standardized room air humidity".
The technique of tracer gas measurement has during recent years tended towards increasingly complicated measuring methods. The new measuring techniques are essential in order to procure more information about the circulation of air through buildings, or in order to perform more accurate measurements in large and complex buildings. The measuring method by means of "constant concentration of tracer-gas", which has been applied at Technological Institute for about 7 years, has proved to be a very accurate measuring method for both small and very large buildings.
A unique multiple tracer experimental system has been developed and utilized within commercial buildings to monitor ventilation rates, air exchange efficiency, ages of air (at multiple indoor locations), flow rates of supply and outside air, and percent outside air in supply airstreams. The multiple tracer technique also makes it possible to determine the fractions of air at a monitoring point that entered the building through a particular air handler and by infiltration.
This text contains comments to the poster presented at the 9th AlVC Conference in Gent, Belgium. The project under consideration in the poster (Climatological Data Transfer) is one of the numerous research fields of the Swiss ERL program (Energierelevante Luftströmungen in Gebaüde - Energy Relevant Air Flow in Buildings).
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