Study on the isolation effect of negative pressure isolation ward for infectious disease

摘要

Through the theoretical and experimental study on the factors of pressure and temperature difference, door opening and people movement, and the corresponding influence on the contaminant transmission, we presented that the high negative pressure and air-tight door could only provide static isolation. And such function would be eliminated under dynamic conditions such as door opening and people movement. Furthermore we found that the nominal design of the inlets and outlets could not provide acceptable protection for the health care workers (HCWs) when they work by the bed. So this paper presented the concept of dynamic isolation, strengthened the effect of buffer room, and consequently quantified the isolation effect as isolation factor. We strengthened the air distribution scheme of main flow area to protect the HCWs by the bed as well. Finally all theoretical analysis met very well with the measurement from bio-aerosol, atmosphere dust experiments. An acceptable agreement of the calculated isolation factor and measured one was then founded.