ONE ZONE OR 2 ZONES IN THE ROOM OF FIRE ORIGIN DURING FIRES - THE EFFECTS OF THE AIR-HANDLING SYSTEM

A two-zone model, CFAST, has been widely used in the fire research com munity. However, this study indicates that the CFAST model generally o verpredicts the upper layer temperatures in the burn room because the zonal assumption is likely to break down in the burn room. It was foun d that the room-averaged temperatures obtained from the CFAST model we re in good agreement with the experimental results (one zone assumptio n in the burn room). The prediction of CO concentration is inconsisten t. The CFAST model tends to overestimate CO concentration when the air -handling system is in operation, and to underestimate CO when the sys tem is off.