Assessment of the air change rate of airtight buildings under natural conditions using the tracer gas technique. Comparison with numerical modelling

Abstract Under natural conditions, air change rates are very sensitive to specific building elements and to climate conditions, even more so in the case of airtight buildings. Consequently, applying general correlations to such cases may lead to inaccurate predicted air change rates. Still, this approach remains valuable because of its simplicity compared to other methods such as wind tunnelling and CFD simulations. In this paper, the tracer gas concentration decay technique was selected to contribute additional information to classical air-tightness measurements. The measurements were used to fit the coefficients of a general single-node pressure model. Simulation results were found to be consistent with tracer gas measurements most of the time. However, the closeness of the fit is strongly related to the average pressure coefficients from the literature, which were estimated more precisely using the other techniques mentioned above. From a general point of view however, it would seem promising to extend this method to other buildings.

[1]  Arnold Janssens,et al.  Effects of wind on the transmission heat loss in duo-pitched insulated roofs: A field study , 2007 .

[2]  Carl-Eric Hagentoft.  Introduction to Building Physics , 2001 .

[3]  K.W.D. Cheong.  Airflow measurements for balancing of air distribution system — tracer-gas technique as an alternative? , 2001 .

[4]  Dries Berckmans,et al.  Influence of sampling positions on accuracy of tracer gas measurements in ventilated spaces. , 2009 .

[5]  Bje Bert Blocken,et al.  On the effect of wind direction and urban surroundings on natural ventilation of a large semi-enclosed stadium , 2010 .

[6]  Chris J. Koinakis.  The effect of the use of openings on interzonal air flows in buildings: an experimental and simulation approach , 2005 .

[7]  Jlm Jan Hensen,et al.  Uncertainty in airflow rate calculations due to the use of surface-averaged pressure coefficients , 2010 .

[8]  Joseph Virgone,et al.  A comparative study of two tracer gases: SF6 and N2O , 2001 .

[9]  Max H. Sherman,et al.  A comparison of the power law to quadratic formulations for air infiltration calculations , 1998 .

[10]  K. Pavlou,et al.  Experimental investigation of the air flow and indoor carbon dioxide concentration in classrooms with intermittent natural ventilation , 2008 .

[11]  Adil Sharag-Eldin,et al.  A parametric model for predicting wind-induced pressures on low-rise vertical surfaces in shielded environments , 2007 .

[12]  M. Sandberg,et al.  Some examples of solution multiplicity in natural ventilation , 2001 .

[13]  Bernard Tourancheau,et al.  TOWARDS URBAN-SCALE FLOW SIMULATIONS USING THE LATTICE BOLTZMANN METHOD , 2011 .

[14]  Monika Woloszyn,et al.  The effect of combining a relative-humidity-sensitive ventilation system with the moisture-buffering capacity of materials on indoor climate and energy efficiency of buildings , 2009 .

[15]  Per Heiselberg,et al.  Single-sided natural ventilation driven by wind pressure and temperature difference , 2008 .

[16]  M. N. Assimakopoulos,et al.  Air tightness measurements of residential houses in Athens, Greece , 2008 .

[17]  A. Piot.  Hygrothermique du bâtiment : expérimentation sur une maison à ossature bois en conditions climatiques naturelles et modélisation numérique , 2009 .

[18]  N. Isyumov,et al.  Wind pressures acting on low-rise buildings , 1999 .

[19]  D. Timlin,et al.  A method for estimating carbon dioxide leakage rates in controlled-environment chambers using nitrous oxide , 2004 .

[20]  Armando C. Oliveira,et al.  Solar chimneys: simulation and experiment , 2000 .

[21]  Man Pun Wan,et al.  Ventilation performance measurement using constant concentration dosing strategy , 2004 .

[22]  H. Plaisance,et al.  Screening of formaldehyde indoor sources and quantification of their emission using a passive sample , 2011 .

[23]  Juslin Kouadio Koffi.  Analyse multicritère des stratégies de ventilation en maisons individuelles , 2009 .

[24]  B. Moshfegh,et al.  A comprehensive investigation of a low-energy building in Sweden , 2007 .

[25]  L. U. Opara,et al.  Use of carbon dioxide as a tracer gas for determining in-package airflow distribution , 2000 .

[26]  Monika Woloszyn,et al.  Experimental wooden frame house for the validation of whole building heat and moisture transfer nume , 2011 .

[27]  Carsten Rode,et al.  The international building physics toolbox in Simulink , 2007 .