English

Estimates of air infiltration in houses based on tracer gas measurements have usually assumed house is a single perfect mixing chamber with incoming air instantaneously and uniformly diffused to all parts of the interior. Points out that in reality some parts of the house - basement or rooms with doors closed - exchange air only very slowly with other parts so that actual mixing is far from instantaneous. Presents theory and mathematics necessary to apply tracer gas method to buildings of many chambers.

Discusses in theoretical terms complexity of interactions of weather-driven air infiltration by 1) wind and 2) convection induced by indoor/outdoor temperature difference. Notes implications for practice of this complexity such as near impossibility of achieving accurate computer models. Treats flow through a single crack. Illustrates diagrammatically and discusses nature of the interaction of the 2 effects for several idealised examples. In an appendix proves mathematically the subadditivity of the effects for a wide class of situations.

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.

Describes behavioural studies of the window opening habits of families in 123 houses to show strong seasonal pattern. During winter, window opening is closely related to moisture levels in the external air. In summer it is most closely linked to outside temperature. Larger families have more open windows. Re-examines ventilation criteria to suggest 3 seasons : deep winter with minimum ventilation for body odour removal ; spring/autumn for controlling moisture and summer for cooling.

Presents calculations of mean temperatures and relative humidities , shown graphically for three typical housing types assuming different heat and moisture inputs: 1) whole house uniformly heated with moisture from household activities uniformly distributed; 2) kitchen at constant temperature with high moisture emission rate; 3) unheated bedroom with two occupants assumed to be in thermalequilibrium with a room below at 15 c. Concludes that there is a certain critical amount of heat needed to give a relative humidity of less than 70% and thus avoid the danger of mould growth .

Describes pressurization method of measuring air leakage using a fan installed through an open window. Gives results of survey of 24 houses. Humidity, meteorological parameters, indoor particulate levels, measured equivalent leakage areas and other information were recorded. Finds that tight houses tend to havehigher humidity, that leaky houses require more heating energy and that houses where smoking takes place have higher air pollution levels than others.

Describes experiments emitting a gaseous tracer (methane) into a ventilated test room and measuring gas concentration with rapid-response hydrocarbon analyser. Parameters were contaminant source location, sample location and ventilation rate. Measures equilibrium concentrations and rates of decrease in concentration following cessation of tracer release. Subjects data to multifactorial analyses.

Presents documentative report of findings of research into effect of weather on internal environment in buildings. Presents results to promote their further application. Defines problem as that of applied meteorology and illustrates its distinguishing features. Evaluates physical assumptions made in establishing mathematical model. Notes limitations of results. Presents worked solutions for numerous locations in USSR and discusses way of improving calculation methods. Indicates direction of further research.

Investigates energy balance of centrally heated flat at coastal town of Kijkduin, based on daily figures of gas consumption and ventilation losses derived from meteorological conditions. Studies: 1) pressure difference over the building caused by windvelocity, wind direction and outdoor air temperature; 2) natural ventilation caused by pressure differences over fortuitous cracks and intentional opening of windows, grilles and shafts. Studies possibility of ventilation prediction via mathematical model.