50 occupants of terraced houses, divided into 4 groups, were surveyed three times in October 1981, February 1983 and March 1983. The first group had Isolair air heating and ventilating systems, and were well insulated with double glazing. The second group was heated by radiators and had the same insulation as group 1. Groups 3 and 4 had normal insulation. Results of the surveys are given. The air heating and ventilating system did not provide the level of satisfaction hoped for. The group with the air heating and ventilating system was surveyed again in March 1984.
With correct application of vapour barriers the ventilation of building structures is in general not necessary, unless such barriers prevent the escape of trapped moisture from moisture-sensitive - especially organic - materials. Indoor and outd
Aerodynamic phenomena affecting the ventilation process, such as aerodynamic mixing, generation of secondary and slightly turbulent flows, roof contours, infiltration and convection and their connection with geometric parameters of the object and energy expenditure for ventilation are analysed.
Ventilation is widely used to help maintain acceptable indoor pollutant concentrations. In this paper, the relationships between ventilation rate and indoor concentration are examined by the use of mass balance models and measured data. It is shown that the pollutant source strength and pollutant removal by processes other than ventilation can have a large impact on the indoor concentration and that maintenance of a typical ventilation rate does not ensure an acceptable indoor concentration.
Plastic track detectors LR-115 and CR-39 were used to estimate the concentration of radon-222 and its daughter products (218Po, 214Po) in a room by recording tracks of their alpha-particles. Although the ventilation rate is the main factor th
The effectiveness of range hoods and window fans in removing indoor pollutants is considered. Tests were conducted in a two-room test space with an infiltration rate less than 0.1 hr-1 using sulphur hexafluoride as a tracer gas. Range hood te
Describes the technique employed, including the mathematical model as well as results from a validation test using an experimental chamber. The model assumes an exponential decay of the tracer gas concentration. The precision of the analytical procedure is estimated at better than 9%, while the error of the measured ventilation rate of the test chamber was 5%.
A tracer method was developed for the evaluation of workplace ventilation. Nitrous oxide or freon was used as the tracer. The concentration of the tracer gas was measured with an infra-red analyser. The versatility of the tracer technique for industrial hygiene applications was improved by the use of a microcomputer for data calculation, display and storage. Three applications are presented: 1. determination of the capture efficiency of a local exhaust hood, 2. the evaluation of the air leakage of a room, and 3. measurement of the local ventilation rates in a large industrial plant.
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