A computer analysis of stack effects in a large multi- storey building was performed, comparing the air flow (and consequent hypothetical smoke concentrations at higher floors) with and without a smoke shaft. Additionally, tests were performed on one building using one of two stairwells as a smoke shaft. Results indicate that a smoke shaft can be effective in limiting smoke movement to upper stories, as long as the fire floor is not open to outside air (such as by a broken window), or the smoke shaft is not open to a floor higher than the fire floor.
This paper describes a set of velocity measurements which were made within a series of models of rectangular enclosures whose dimensions in plan were varied, the heights of the walls being held constant. The airflow's speed was measured at each of the points of a rectangular grid and the arithmetic mean of these measurements was adopted as a measure of the enclosure's performance in providing shelter from the wind, and was used to compare the effectiveness of one geometry against another. It was found that the degree of shelter could be optimised by a correct choice of geometry.
For proper control of the ventilation in a building, it is necessary to know the factors involved. These include (1) the climate, including temperature, wind direction, and wind velocity, (2) the building performance, (the interconnections b
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.
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
An analysis of ventilation necessary to maintain air quality in an above-ground fallout shelter was done, making use of theoretical models, and generalizing the results to fit measurements on actual shelter data. Results show that, at most, boundary surface heat loss serves as a safety factor for ventilation systems, and thus ventilation systems should be designed to remove the entire thermal load generated within the shelter. This, when considered in addition to weather and load expectations, establishes an upper limit on ventilation equipment size.
A comprehensive computer program for the prediction of air flow and smoke migration in the building was applied to the 11 story administration building of the National Bureau of Standards. Natural air leakage rates under various climatic conditions for several ventilation system operations were obtained. The computed results were compared with measured air leakage rate by using the sulphur hexafluoride tracer gas technique. Smoke migration was simulated for the selected pressurization conditions.