USE OF A PORTABLE HEPA AIR CLEANER IN A HOSPITAL WARD FOR REDUCING DISEASE INFECTION

Use of a portable HEPA filter cleaner in a room is believed to be capable of reducing the risk oftransmission of infectious diseases through removing the particles or large droplets to which pathogensare attached. It is hoped that the portable HEPA filter(s) can increase the effective air change rate (forparticle removal only) in a general ward to the ventilation standard of an isolation ward for emerginginfection diseases when there are insufficient number of isolation wards. An experiment was conductedin a full scale experimental ward with a dimension of 6m6.7m2.7m and 6 beds to test theperformance of a portable HEPA filter cleaner. The removal efficiency for different size particles wasmeasured at different locations. The influence of the portable HEPA air cleaner on the airflow patternwas also studied through smoke visualization and CFD simulations. The results show that the HEPAfilter can decrease effectively the particle concentration level, and the effective air change rateachieved by HEPA filter (for particle removal only) is ranged 2.7-5.6 ACH in the ward. The strong supplyair jet from the portable HEPA filter cleaner interacted with the room airflow pattern and becamedominated, introducing a global airflow mixing in the room.