PERFORMANCE OF SPRINKLER IN ATRIA

The performance of a sprinkler installed in an atrium roof was evaluat ed in this paper by considering three points: possibility of activatin g the sprinkler head, thermal response, and water requirement. Crude a nalysis using the empirical expressions of the fire plume and the zone model CFAST 2.0 were used to study the possibility of activating the sprinkler head. Smoke spreading out from a fire shop to the atrium was discussed. The software DETACT was used to calculate the activation t ime for the sprinkler heads of different response time indices install ed at different ceiling heights under unsteady t-squared fires. Correl ation expressions of the activation time with ceiling height, response time indices of the sprinkler head, fire growth coefficients, and amb ient temperature were derived. The water requirement at the atrium flo or was discussed by calculating the trajectories of water droplets. Hi gher flow rate and pressure are required for discharging the same wate r density at the floor level. Results indicated that installing an ord inary sprinkler system in a high headroom atrium would not be effectiv e in controlling a fire.