Gives an account of a method of measuring the ventilation rate of a room using hydrogen as a tracer gas. Describes katharometer used to detect the gas and the experimental procedure. Results agree well with those calculated by orifice plate method.
Outlines ventilation measurements being made on two storey semi-detached houses using helium as a tracer gas. Describes measurement of decay rates in single rooms, the recirculation between two rooms and by summation the ventilation rate of thewhole house. Describes installation used to measure ventilation rates when homes are occupied without interfering with the normallife of tenants.
Reports study of the potential for energy saving in an old low-rise, 50 unit apartment building. Energy use and heat balance of the building are calculated including heat loss through conduction and air infiltration. Also gives estimate of infiltration rate from a room found using first water vapour thensulphur hexafluoride as a tracer gas. Suggests various strategies for energy conservation which would result in a 30% saving in fuel. Methods are applicable to a wider class of old buildings
Compares methods of calculating ventilation rates in mechanically ventilated animal houses. Ventilation rates in several occupied animal houses were found by 1) measurement of internal to external temperature and moisture differences using a psychrometer;2) measuring decay rates of radioactive krypton as a tracer gas;3) estimating from manufactures rating of fans. Concludes that different methods agree to within the order of 5 or 10% and suggests the use of psychrometer techniques for simplicity.
Gives measurements of air infiltration made in ten houses in Indiana using helium as a tracer gas. Assumes linear dependence of infiltration rate on temperature difference and wind velocity and calculates infiltration rate per unit crack length. Change rates ranged from about 0.6 to 1.5 changes per hour.
Reports measurements of infiltration rates in two research houses in Minnesota under different wind, temperature and inside operating conditions using helium as a tracer gas. Suggests linear dependence of infiltration rate on temperature difference and wind velocity. Found infiltration rates varied from 0.1 to 0. 4 changes per hour
Reviews methods of measuring infiltration rates. Describes tests made on a mobile home using carbon monoxide as a tracer gas and measuring the rate of decay. Concludes that infiltration rates depend primarily on whether or not the blowers for air conditioning or heating are turned on. Without blower the infiltration rate was of the order of 0.8 changes per hour, with the blowers it was 1.2 to 1.7. Reported linear dependence of infiltration rate on temperature difference but did not identifya dependable trend on the effects of wind.
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.
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.
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.
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