The estimate of actual air change rates considering atmospheric turbulence isintroduced. The starting point is the spectral description of turbulence - Kaimalspectrum was used in order to consider the height above ground. A set of syntheticwind velocity series are generated, out from a modified spectrum. The procedureconsiders an aerodynamic transfer function (a filter) where peculiar and cut-offfrequencies are determined by the general dimensions of the building and of theexternal openings, i. e., the turbulent scales of interest.
The paper presents a short description of the measurement program and the data collected for the “SynergieHaus”-project initiated by PreussenElektra and partners (now merged to E.ON). Results of airtightness measurements (ACH 50-values) are shown for a to
Some techniques aimed at the evaluation of microclimatic parameters through the measurement of other indoor physical quantities are critically reviewed. Particularly, the appraisal of the air velocity from the predicted mean vote and the determination of air change from the decay of the C02 indoor concentration are analysed. Important warnings for the use of these methods are underlined and the limits of applicability are pointed out.
Describes a method for determining the air change rate in a room or a building by continuous monotoring of the CO concentration in both supply and exhaust air. By using a mass balance equation, the indoor concentration of CO can be numerically calculated for various air change rates. The value of the air change rate used in the equation that gives the best correlation between measured concentration and calculated concentration provides an estimate of the air change rate for the volume studied.
Indoor air quality was monitored at two schools in Essex, UK (located on the same site) during the week 3--7 November 1997. The objective was to determine whether the ventilation rates within the buildings were adequate to provide acceptable air quality to the occupants. Airborne carbon dioxide concentration was determined using continuous infrared detectors. A class base in each school was monitored for a two-day period. Occupancy patterns and window/door opening were observed during the first day of each period. Air temperature was also recorded.
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