Describes measurements of air change rates using radioactive krypton as a tracer gas in a domestic house. Reports measurement of air change rates for a single room heated by either an open fire or a central heating radiator. Examines effect of opening doors and windows and rate of flow up chimney. Found with all the doors open very large airflows from heated downstairs roomsto unheated upper storey, causing large heat transfer to bedrooms: if bedroom doors were shut very little warming of bedrooms took place.
Describes measurement of wind pressures on low-rise buildings at Aylesbury. Pressures were recorded simultaneously at over one hundred positions divided between seven houses in an estate and a specially constructed building situated on open ground adjoining the state. The roof pitch of the experimental building could be quickly varied to any angle between 5 and 45 deg. and this was used to investigate the variation of pressure distributions over the surfaces of the building. Data are presented for two skew wind directions. Initial comparisons are made with wind-tunnel tests.
The fundamentals of natural ventilation are discussed with particular reference to the ventilation of houses. The laws of flow are presented and typical values are suggested for the acting pressures and the size of openings through which flow canoccur. As an example of the application of the laws, the effect of wind and temperature difference on the ventilation of an exposed house is discussed, and the theoretical treatment is illustrated by experimental results.
Defines ventilation requirements for spaces intended for human occupancy and specifies minimum and recommended air quantities for the preservation of the occupants health, safety and well-being. Recommendations are given for different rooms in alltypes of building in terms of the outdoor air supply per minute. Also gives maximum concentrations of various contaminents. States that outdoor air requirement can be reduced if air is recirculated, purified or odour or gas removal equipment used, but in no case should be less than 5 c.f.m per person.
States that to calculate the ventilation characteristics of a building it is necessary to know the shape, planning and dimensions of the building, air leakage characteristics of all elements of the building, aerodynamic coefficients, wind velocity and internal and external air temperatures.
After retrofitting of town houses at Twin Rivers it was found that heat loss from attics was much higher than predicted. This was accounted for by heat transfer within the wall dividing adjacent townhouses (party wall) from each other. This occurs both by conduction and by air movement through vertical holes in the party wall. Suggests that basement is thermally coupled to the attic and adjusts the model to allow for this, giving a three-zone model for the house
Describes the ventilation of buildings by analogy with electric circuits and derives expressions for ventilation with and without flow through ducts in the roof. Finds that in general ventilation rate will vary linearly with wind velocity. Considers the effect of shelter belts on wind velocity and derives expression for sheltered ventilation rate. Suggests that eddy motion caused by shelters may be important. Gives measurements made on models in wind tunnels to show the affect on wind pressure of sheltering buildings at various distances.
Describes measurements made of wind speed and direction and pressure differences across the exterior walls of two multi-storey buildings in Montreal. Regression coefficients are obtained and show better correlation for higher levels than forlower ones and for the taller building "A" than building "B", indicating that shielding by adjacent buildings has an important effect. The variation in wind velocity between the site and a meteorological station was recorded.
Describes a method of analysing the stack effect on a multi-storey building. The building is divided into zones and a computer programme calculates air-flow and pressure for each zone. Analysis is given for an example hypothetical building under different temperature, wind and air leakage conditions. Shows that the method can be used to evaluate the difficulty in opening doors due to pressure differentials and the noise resulting from air flowing through cracks around doors.
Describes a method for determining the rate of air change in a ventilated space using carbon monoxide as a tracer gas. Concentration of carbon monoxide was found by an infra-red analyser which proved to be very precise and sensitive and made it possible to carry out analyses in a short time. Air change rates were measured in a laboratory with open windows and with closed windows. Concludes that air change rates are greater with few large openings than with many small ones.
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