Natural Venting to Control Smoke Movement in Buildings Via Vertical Shafts

Effects of vertical shaft venting on smoke movement in tall buildings are examined in order to obtain conditions for minimum smoke filtration into upper floors, stairways, and elevator shafts during fires. Results show that sufficient bottom venting will nearly eliminate flow of air into shafts, while top venting reduces flow from shafts. Either should reduce smoke transfer between levels. Multiple shaft buildings benefit from top ventingsome and bottom venting others, reducing necessary vent size for sufficient ventilation.