Experimental Measurements of Particles and CO2 Exhaled by a Manikin in a Hospital Room

The relation between the concentration and particle size of the human breathing and the way in which these particles are dispersed in hospital indoor environments are studied in this research. Breathing thermal manikins are used to, experimentally, simulate a human person and its breathing activity. Two breathing thermal manikins are placed in a hospital room, simulating an infected patient, together with another standing manikin simulating a health worker. 0.665 and 1.095 um sized particles and CO2 tracer gas are injected in the exhalation of the patient manikin simulating exhaled contaminants. The results show that the breathing function of patient manikin (exhaling through the mouth or through the nose) influence the personal exposure to contaminants at certain distance from the contaminants source for the largest particles (1.095μm). The microenvironment generated by the two BTM and the direction of the exhalation flow have a significant influence in the dispersion and exposure of the exhaled contaminants. It is shown that the dispersion of the exhaled particles (0.665μm) and the CO2 is similar in the two positions measured. However, the largest particles (1.095 µm) show significant differences at certain distance from the exhalation source. The results show the pros and cons of each measurement strategy (particles and tracer gas) in order to obtain, from an experimentally point of view, an accurate prediction of a personal exposure index between people in a hospital room.