Points out mistakes in text book formulae for determining the flow rate of fresh air. Provides a new approximate formula for this. Establishes a differential equation for air change rates and derives a generalized equation for ventilation incorporating only three parameters. Provides curves for determining the fresh air flow rate and gives calculated examples.
Describes methods of calculating ventilation heat losses employed in several European countries. Compares them from standpoint of air change rates. Proposes calculation procedure for new Czechoslovak standard CSN 06 0210.
Summarises results of research project comprising survey of air tightness and natural air change rates in various types of residential building. Briefly describes equipment for pressurization tests and tracer gas measurements. Compares properties, range of measurement and cost of 5 different tracer gases. Provides some results from measurements in 53 single family houses and 28 flats. 9 of tested dwellings had their tightness improved and supplementary measurements made.
Outlines necessary ventilation rates for an occupied room. Discusses natural ventilation of a room through openings in the ceiling. Discusses natural draught ventilation for single family houses, combined natural draught and mechanical ventilation, mechanical fresh air ventilation based on a central duct, fortuitous ventilation caused by air infiltration and leakage. Compares natural and mechanical ventilation. Considers supplyair systems for single family houses, warm air heating and possibilities for heat recovery.
Expresses air infiltration rate measured using tracer gas in 2 similar town houses in terms of wind speed, wind direction, indoor-outdoor temperature difference, average rate of boiler firing and fraction of time that doors are open. Method yielded reproducible rates of air infiltration within 0.1 air exchanges per hour in any single one-week run once outside temperature, wind speed and wind direction were allowed for. States results partly reveal set of physical principles determining house air exchange rates which are so far poorly understood.
Discusses use of tracer gases for the measurement of natural ventilation rates States advantages of using radio isotopes are increased speed and sensitivity. Gives expressions for calculating air change rates using radio isotopes from thedecrease in signal. Suggests use of krypton 85 or Xenon 133 as tracers. Discusses errors in the method. Reports study of air quality in a naturally ventilated building in Yakutsk. Air change rates, temperatures and concentrations of carbon monoxide were measured in kitchens with gas stoves.
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