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The
International Journal of Ventilation
Volume 3 No 2 September 2004:
Paper 4: Analysis of Contaminant Removal Efficiency Assessment in a
Ventilated Room
Ake Ahiman Akoua1,
Francis Allard2, Claudine Beghein2, Bernard Collignan1
1
C.S.T.B., Centre Scientifique et Technique du Bâtiment, Marne la Vallée,
France.
2
L.E.P.T.A.B., Laboratoire d’Etude des Phénomènes de Transferts Appliqués au
Bâtiment,
La Rochelle, France.
Abstract
This paper reports a critical
analysis of the assessment of contaminant removal efficiency. Measurements have
been carried out in a ventilated room equipped with a pine wood floor, which
emits Volatile Organic Compounds (VOCs), considered as air pollutants in this
paper. Thereafter, Computational Fluid Dynamics (CFD) simulations are performed.
CFD results are compared to measurements to check their accuracy. Moreover, air
quality within the ventilated room is numerically analysed via indices. From
this, it is shown that the currently used contaminant removal efficiency index, εc,
can especially reveal the characteristics of contaminant distribution.
Unfortunately, εc is not suitable for assessing the
contaminant removal efficiency of ventilation scenarios with different air flow
rates. Indeed, its definition does not take into account absolute contaminant
concentration levels. Furthermore, since the VOC concentrations found in this
study were very low compared to the Lowest Concentration of Interest, no health
risks could occur, and so, it was inappropriate to use the Indoor Air Quality
index IIAQ. Therefore, a new formulation of εc
is proposed. Its values are analysed taking into account the conformity degree
of the ventilation rate with the nominal air flow rate of the ventilation
systems handled. This gives a good tool to compare the contaminant removal
efficiency whatever the ventilation rate.
Key words:
Ventilation removal efficiency, indoor air quality, volatile organic
compounds, experiment, CFD.
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