Airborne Cross-Infection Risk Between Two People in a Displacement Ventilated Room

Peter V. Nielsen, Inés Olmedo, Manuel Ruiz de Adana, Piotr Grzelecki, Rasmus Lund Jensen

Research output: Contribution to book/anthology/report/conference proceedingArticle in proceedingResearchpeer-review


Transmission of exhaled small particles from one person to another in an indoor environment can take place, both in a direct way (in the microenvironment around the persons) and via the room air distribution. The impacts of these transmission routes for two persons are investigated in details by evaluating the exposure to gaseous substances (simulating particles < 5 μm) in a room ventilated by displacement ventilation. Experiments employing two breathing thermal manikins are conducted in a full-scale test room. One manikin is the source, and the other manikin is the target. The distance between the two manikins varies from 1.1 m (43 in) to 0.35 m (14 in) in the experiments. A tracer gas N2O is used to represent the gaseous substances exhaled by the source manikin. The concentration of N2O is measured to study the impact of the following parameters on the exposure: distance between manikins, positions as face to face, face to the side of the target manikin, face to the back of the target manikin, and a seated source manikin. The exposure increases with decreasing distance between the manikins, and the highest values are obtained in the face to face position. Face to the side is also giving some exposure of the target manikin, while face towards the target manikin’s back does not give any direct exposure through the microenvironment. The thermal stratification in the room supports a significant exposure of the target manikin when the source manikin is seated breathing towards the chest of a standing manikin.
Original languageEnglish
Title of host publicationIAQ 2010: Airborne Infection Control : Ventilation, IAQ, and Energy
Number of pages6
PublisherAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.
Publication date2011
ISBN (Electronic)978-1-936504-04-6
Publication statusPublished - 2011
EventASHRAE IAQ Conference 2010 - Kuala Lumpur, Malaysia
Duration: 10 Nov 201012 Nov 2010


ConferenceASHRAE IAQ Conference 2010
CityKuala Lumpur

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