Experimental assessment of different mixing air ventilation systems on ventilation performance and exposure to exhaled contaminants in hospital rooms

This study evaluates the convenience of the use of four different mixing ventilation configurations in individual hospital rooms (]HR) based on ventilation performance and health workers (HW) exposure to the contaminants released by a confined patient (CP). Two supply configurations: grilles in the upper part of a wall (G) and swirl ceiling diffusers (S), combined with two different exhaust grilles positions in the opposite wall: upper part (U) and lower part (D) are tested using typical IHR set up. Occupants are represented by thermal breathing manikins, CP lies on a bed while HW stands close to it. Three air renewal rates are tested to determine their influence in the studied variables, 6, 9 and 12 ACH covering the whole range of ventilation requirements of such spaces. The experimental conditions considering the thermal comfort of the occupants are taken into account. Different ventilation configurations create different air distribution patterns inside the room. G configurations lead to high HW transient exposure values while S maintain low values that decrease when ACH is increased, so this second configuration is preferred for IHRs, Results are also compared with a displacement ventilation (DV) study highlighting the convenience of this strategy for IHRs. (C) 2018 Elsevier B.V. All rights reserved.