The ventilation of a test room (LxWxH = 5.4x3.6x2.4 m) with a wall mounted heat source is investigated for two different air terminal devices. The properties of each air terminal device are described by measuring the velocity decay of the primary wall jet below the ceiling. The velocity distribution in the plume above the heat source has been measured at different heat loads as a function of the distance to the wall and the distance to the heat source.
This work is concerned with measuring air flows between the floors of houses. A simple measuring technique is described in which two portable SF6 systems were employed. The design and construction of the portable system are presented. A comparison of air flow patterns in a superinsulated house and a standard house is made. Results showed that the air flow between the upper and lower floors of the superinsulated house was about 20 m3/h compared with 100 m3/h in the traditionally built house.
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.
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.
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 describes a two-dimensional numerical study, by finite-volume method of buoyancy-driven flow in a half-scale model of a stairwell. The stairwell forms a closed system within which the circulation of air is maintained by the supply of heat in the lower floor. The heat loss takes place from the stairwell walls. The mathematical model consists of the governing equations of mass, energy, momentum and those of the k - E model of turbulence. The predicted flow pattern and the velocity in the stairway are presented and compared with the authors' experimental data.
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