Cross infection in hospital wards with downward ventilation: different locations of return openings without and with partitions between beds

A two-bed hospital ward with one standing healthcare assistant and a ceiling-mounted low-impulse semicircular inlet diffuser is simulated in a full-scale room. Tracer gas is used for simulating gaseous contaminants, and the concentration is measured at different air change rates and different postures of the patients. A textile partition between the beds, which is typical in a hospital ward, is used for protection of the patients in some of the experiments. Three different layouts of return openings are tested. One layout with one opening at the ceiling, another with four openings at the wall opposite to the inlet diffuser, and one with a high location of these four openings. The downward recirculating flow is on average parallel with the partition, and the partition does not decrease cross infection. A high location of the four return openings decreases the risk of cross infection.postprintThe 11th International Conference on Air Distribution in Rooms (RoomVent 2009), Busan, South Korea, 24-27 May 2009. In Proceedings of the 11th International Conference on Air Distribution in Rooms, 2009, p. 770-77

Cross infection in a hospital ward and deposition of particles exhaled from a source patient

The cross infection in a hospital ward is studied. Deposition of particles exhaled from a source manikin is investigated in a full-scale hospital ward ventilated by downward directed ventilation. Deposition on vertical surfaces close to the source shows distribution of particles directed upwards in the room. Deposition at the four beds shows that particles smaller than 10 μm disperse evenly in the ward, indicating that particles smaller than this size are airborne. The influence of top and bottom extraction openings on dispersion of particles is investigated. Results show that vertical distribution in the room is not affected by the position of the return openings. Deposition of particles at the four beds gives some indication of a less wide spread of particles with the use of ceiling-mounted return openings, and thereby a better protection of patients compared with bottom return openings.postprint第五届居住建筑能源与环境国际研讨会 (EERB) & 第三届建筑环境与公共健康国际学术会议 (BEPH), 中国, 桂林, 2009年5月29至31日.The 5th International Workshop on Energy and Environment of Residential Buildings and the 3rd International Conference on Built Environment and Public Health (EERB-BEPH 2009), Guilin, China, 29-31 May 2009

Risk of cross-infection in a hospital ward with downward ventilation

A two-bed hospital ward with one standing healthcare person and a ceiling-mounted lowimpulse semicircular inlet diffuser is simulated in a full-scale room. Tracer gas is used for simulating gaseous contaminants, and the concentration is measured at different air change rates and different postures of the patients. A textile partition between the beds, which is typical in a hospital ward, is used for protection of the patients in some of the experiments. Three different layouts of return openings are tested. One layout with one opening at the ceiling, another with four openings at the wall opposite to the inlet diffuser, and one with a high location of these four openings. The downward recirculating flow is on average parallel with the partition, and in most cases the partition does not decrease cross-infection. A high location of the four return openings decreases the risk of cross-infection. © 2010 Elsevier Ltd.link_to_subscribed_fulltex