Fifty-nine owners/occupants of electrically heated houses in the Denver, Colorado area have, for about ten months, been participating in a study sponsored by the Electric Power Research Institute (EPRI) to determine theeffect of air infi
Several empirical models of house air infiltration, available from the literature, were reviewed and evaluated. Without exception, the limitations, inherent in these models, were found to stem from inadequate accounting of the interactive forces controlling air infiltration. In general, each of the available models was found to accurately reflect the specific real case used for verification, but extension of the model to other structures and situations was found to be totally inadequate.
A systematic series of tests measuring probable distribution of wind pressure on buildings over a practically useful range of building proportions was undertaken using a three dimensional tunnel on a wide assortment of simply gabled block type structures. These tests were then extended to thinwalls, hangar type structures, and simple building groups. The possible effects on building codes and construction techniques are discussed.
Models are defined for various mixing conditions, in continuous flow systems. Differential equations are derived which take into account aneffective volume of mixing, possible short-circuiting, hold-up time of the system, partial displacement or piston flow. The values of the different factors contained in the integrated equations can be determined experimentally by the particular response of a given system to a sudden change in composition of the feed. A correlation of the effective volume of mixing and the agitator r.p.m. is presented.
Building services accounts for some 40-50% of the UK's consumption of primary energy. The potential for energy saving through the adoption of such schemes as district heating, combined heat and power, heat pumps and solar energy could make a major contribution to the country's energy balance.
One important factor in the spread of airborne infection must be the movement of the air itself i.e. the ventilation, although an exact correlation of it with the risk of infection has yet to be found. As part of an infection survey in a hospital ward we made a detailed study by physical methods of the movements of the air and of the transport of particles by this means. A description is given of the methods employed.
The objectives of this review are to establish an initial subject-matter base for wind engineering, to demonstrate current capabilities and deficiencies of this base for an engineering treatment of wind-effect problems, and to indicate are
This paper describes an original investigation of a new flowmeter and a method of balancing of airflow circuits in low pressure ventilating systems. The flowmeter is simple and robust in its construction, imposes virtually no resistance to
The problem of describing quantitatively the effective ventilation in a room when the air within the room is imperfectly mixed is discussed. It is suggested that the protection afforded by the ventilation to any given position against air
The pressure drop and flow characteristics of short capillary tubes have been investigated experimentally for length-to-diameter ratios varying from 0.45 to 18 at diameter Reynolds numbers ranging from 8 to 1500. In the range of the dime
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