Tracer-gas studies of the recirculation of exhaust air in urban buildings Abstract Under certain atmospheric conditions, a significant fraction of toxic building-exhaust emissions may be captured by the fresh-air intakes of the same building or adjacent ones and recirculated, creating a health risk for building occupants. This problem is particularly acute in industrial and institutional laboratories. Determination of the minimum safe distance between exhausts and fresh-air intakes in urban settings is a complex exercise that must take into account many parameters. The primary objectives of this tracer-gas field study were to evaluate the minimum-dilution models suggested by the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) and to determine the reliability of wind-tunnel simulations. One of the ASHRAE models was found to be most applicable to situations involving toxic gases, while two others were better suited to situations involving foul-smelling gases. For buildings with complex geometries, wind-tunnel models are preferable to the ASHRAE models. Produced Under this Project Scientific Reports Tracer gas study of the recirculation of exhaust air in urban buildings Research Report: R-214, R-213 Simplified Articles Qualité de l'airLa fiabilité de trois modèles mathématiques de dispersion atmosphérique est comparée pour éviter la réadmission des évacuations dans les édifices Volume 12, n0 4 Scientific Publications Air intake contamination by building exhausts: Tracer gas investigation of atmospheric dispersion models in the urban environmentLazure L., Saathoff P., Stathopoulos T.Source : Journal of the Air & Waste Management Association, vol. 52, no 2, 2002, p. 160-166Contamination des prises d’air neuf: évaluation terrain par traçage des modèles de dispersion atmospherique en milieu urbainLazure L., Stathopoulos T., Saathoff P.Source : in Congrès de l’Association québécoise pour l’hygiène, la santé et la securité du travail / AQHSST, (21e : 28-30 avril, 1999 : Montréal, Canada), 1999, p. 249-258A Wind Tunnel and Field Study of Dispersion of Exhaust from a Rooftop Stack on a Cubical BuildingSaathoff P., Lazure L., Stathopoulos T., Wei X.Source : in Wind Tunnel Modelling of Dispersion of Exhaust in Environmental Flows, Euromech Colloquium 391 (September 13-15, 1999 : Prague, Czech Republic), 1999Air Intake Contamination by Building Exhausts: Tracer Gas Investigation of Atmospheric Dispersion Models in the Urban EnvironmentLazure L., Stathopoulos P., Saathoff T.Source : in Ventilation 2000, International Symposium on Ventilation for Contaminant Control (June 4-7, 2000 : Helsinki, Finland), 2000The Influence of Freestream Turbulence on Nearfield Dilution of Exhaust from Building VentsSaathoff P., Stathopoulos T., Wu H.Source : Journal of Wind Engineering and Industrial Aerodynamics, vol. 77-78, 1998, p. 741-752Dilution of Exhaust from Rooftop Stacks - Comparison of Wind Tunnel Data with Full-Scale MeasurementsSaathoff P., Wu H., Stathopoulos T.Source : in 9th Joint Conference on Air Pollution Meteorology / American Meteorological Society (9th : January 28-February 2, 1996 : Atlanta, Georgia), 1996 Other Project(s) You May be Interested in Evaluation of Direct Reading Instrument and Filtration Technology Performance to Improve Strategies to Control Workers’ Exposure to Ozone Additional Information Type: Project Number: 0095-2150 Status: Completed Year of completion: 2005 Research Field: Chemical and Biological Hazard Prevention Team: Louis Lazure (IRSST)Ted Stathopoulos (Université Concordia)Patrick Saathoff (Université Concordia)