English

The project is aimed to develop the quantitative method of visualization of the air steams in application to the indoor problems of heauilg , ventilating and air conditioning. The geometrically well defined light sheet is crossing the examined space and determines the plane of observation. The photographic camera is placed perpendicularly to this plane at a distance of a few meters. The flow is seeded with the soap bubbles of the diameter 3-4 mm. The light is reflected from those bubbles which are crossing the illuminating sheet.

In the past few years, research efforts have been made to acquire accurate knowledge about infiltration and ventilation in multi-zone buildings. By this way, a wide variety of modelling techniques have been developed which suffer of a lack of satisfactory validations. The purpose of this work is to set up a data bank of high quality measurements which will serve to cany out an empirical validation of multi-zone air infiltration programs. Among other data, a complete set of air flow permeabilities of a well known experimental midsize building will be included to this bank.

The problem of predicting air flows in a multi-zone building has received considerable attention in the past ten years. An important issue identified by this work was the lack of reliable measurements of the flow resistances between the zones of such buildings. This report analyzes the uncertainties associated with a fan-pressurization technique for measuring the interzonal leakage (inverse flow resistance) in a multi-zone building. The technique involves two blower doors, one in each of the two zones between which the leakage is being measured.

Tracer gas techniques for measuring airflow rates in building systems are considered. These techniques are classified in terms of tracer gas injection strategy employed and mass balance relationships used to analyze measured tracer concentration data. The discussion focuses on one class of tracer techniques - the pulse injection techniques - based upon pulse injection strategies and integral mass balance relationships.

In displacement ventilation systems, air flow rates, temperature and the design of the air supply device strongly influence the parameters which decide the thermal comfort. This paper reviews experiments and theoretical models which show the connection between t.hese parameters. It is indicated that the Archimedes number of the supply air is the parameter which decides the air velocity in the area close to the floor. (The Archimedes number is the ratio between buoyancy and inertia forces).

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.