The risk of airborne cross-infection in a room with vertical low-velocity ventilation
Article first published online: 10 JUL 2012
© 2012 John Wiley & Sons A/S
Volume 23, Issue 1, pages 62–73, February 2013
How to Cite
Olmedo, I., Nielsen, P. V., Ruiz de Adana, M. and Jensen, R. L. (2013), The risk of airborne cross-infection in a room with vertical low-velocity ventilation. Indoor Air, 23: 62–73. doi: 10.1111/j.1600-0668.2012.00794.x
- Issue published online: 9 JAN 2013
- Article first published online: 10 JUL 2012
- Accepted manuscript online: 8 JUN 2012 03:28PM EST
- Received for review 10 February 2012. Accepted for publication 24 May 2012.
- Airborne cross infection risk;
- Vertical ventilation;
- Downward flow;
- Upward flow;
- Exhaled contaminants
Abstract Downward flow ventilation systems are one of the most recommended ventilation strategies when contaminants in rooms must be removed and people must be protected from the risk of airborne cross-infection. This study is based on experimental tests carried out in a room with downward flow ventilation. Two breathing thermal manikins are placed in a room face to face. One manikin’s breathing is considered to be the contaminated source to simulate a risky situation with airborne cross-infection. The position of the manikins in relation to the diffuser and the location of diffuser in the room as well as the distance between the manikins are being changed to observe the influence of these factors on the personal exposure of the target manikin. The results show that the DWF in different situations often is unable to penetrate the microenvironment generated by the manikins. The downward ventilation system can give an unexpected high level of contaminant exposure of the target manikin, when the distance between the manikins is reduced.
Several guidelines recommend the downward ventilation system to reduce the risk of cross-infection between people in hospital rooms. This study shows that this recommendation should be taken into careful consideration. It is important to be aware of people position, position to other thermal loads in the room, and especially be aware of the distance between people if the exposure to the exhaled contaminants wants to be reduced.