Smoke Control Systems Analysis: Balancing Ducts Versus Door Vents in Class B Bulkheads.

摘要

Concern exists over the use of balancing ducts as part of a shipboard ventilation system. These ducts are used in lieu of door vents in allowing for the movement of ventilation return-air from individual compartments to common areas (passageways). The common areas act as plenums, from which the air is then returned to the fan rooms for recirculation. Of primary concern is the fact that these balancing ducts are often installed in the overheads of compartments and might spread the propagation of smoke should a fire occur, thus further endangering the integrity of egress routes. To attempt to quantify the potential hazard associated with the use of balancing ducts, a series of tests were conducted. These tests compared the use of balancing ducts to the vents installed in compartment doors. A test scenario of an accommodation area on a passenger vessel was used for this series of tests. The results of this test series concluded that balancing ducts pose no greater threat to personnel safety than do door vents. These results, however, are confined to the parameters used in this test series. Different scenarios, (i.e., large compartments) and system configurations might necessarily yield different results. This is an area under further study. Balancing duct, Smoke control, Vents.