Describes the measurement of air change rate and airtightness of a mechanically ventilated public swimming bath in Belgium. The relationship between airtightness and air change rate is outlined. Various methods of calculating the air leakage from the pressurization results are compared. Nitrous oxide was used for the tracer gas measurements, which were made both with and without the mechanical ventilation system working. The LBL model was used to calculate the air infiltration rate.
This report describes tracer gas measurements and pressurization tests made on two low-cost houses about one year after their construction. The influence of wind speed on the ventilation rate was found to be significant, whereas stack effect was found to have no significant influence. Infiltration rates of 0.24 and 0.34 h-1 were found. These values are very low for Belgian dwellings. A pressurization and depressurization test was performed for each house at pressure differences between 5 and 150 Pa. The ageing effect was found to be quite substantial.
Presents a detailed description of the measurement technique and apparatus used to measure the air change rate in the Spencer St and Linford low-energy houses in Milton Keynes, UK. An automatic air infiltration rig using nitrous oxide tracer gas constant decay was used. Air leakage was also measured by pressurization for the Linford houses and some from the neighbouring Pennyland project.
This paper presents a quantitative estimate of the error of the decay and constant concentration method. A number of tests were carried out in an indoor test house located in the laboratory hall at the National Swedish Institute for Building Research. The relevant meaning of the concept of air-exchange rate is discussed and an appropriate terminology is suggested. The theoretical background, based on a multi-cell model, of the two tracer gas methods is given.
Large, multicelled and naturally ventilated buildings pose many inherent problems for the measurement of overall infiltration rates using tracer gases. Considering a single tracer gas decay technique, the most obvious problems are: (a) local variations in infiltration, (b) imperfect internal mixing of the air, and (c) practical difficulties in distributing (ie, seeding) the tracer gas and subsequently obtaining air samples.
Mechanical ventilation systems in large office buildings are designed to meet space conditioning loads and to maintain acceptable indoor air quality. In order to achieve acceptable air quality, the ventilation systems are designed to bring in a mlnimrm amount of outside air whenever the building is occupied.
A new method for measuring interzonal air movement, using up to four different tracer gases simultaneously, has been developed at the Polytechnic of Central London and tested in a solar air-heated experimental house in Peterborough, UK.
Large, multicelled, and naturally ventilated buildings pose many inherent difficulties for the measurement of overall infiltration rates using tracer gases.
Air exchange rates were measured in the National Archives Building under various combinations of temperature and wind speed. The average air exchange rate under normal operation of the HVAC system was 0.9 h-1 for an average temperature difference.
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