Skip to main content

Open Access Experimental Investigation of Exhaled Aerosol Transport Under Two Ventilation Systems

Download Article:


Although the importance and implications of studying expiratory droplet concentration distribution in indoor environments are obvious, experimental measurements are very scarce and incomplete. In the work described herein, spatial and temporal aerosol concentrations generated by a modeled expiratory process were studied experimentally. Two heated manikins were placed inside a chamber with either a displacement ventilation system or a ceiling supply and ceiling return ventilation system. One of the manikins emitted 0.05 micrometer monodisperse polystyrene microspheres mimicking the generation of expiratory droplets. Flow characteristics were measured by a hot-film anemometry system before and after the momentary emission of aerosols at three locations. The temporal concentration profiles at eight locations were also measured. The results show that a high-speed air jet easily penetrates the boundary layer of the manikin regardless of the ventilation system used. Transient ventilation effectiveness was also evaluated and compared for both ventilation systems. The results show that the ventilation effectiveness of displacement ventilation is always higher than that of ceiling-type ventilation. Experimental observation also suggests that the presumption of complete mixing must be applied cautiously.

Document Type: Research Article


Affiliations: Department of Building and Construction, City University of Hong Kong, Kowloon Tong, Hong Kong

Publication date: 2010-06-01

More about this publication?
  • Access Key
  • Free ContentFree content
  • Partial Free ContentPartial Free content
  • New ContentNew content
  • Open Access ContentOpen access content
  • Partial Open Access ContentPartial Open access content
  • Subscribed ContentSubscribed content
  • Partial Subscribed ContentPartial Subscribed content
  • Free Trial ContentFree trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more