For the purpose of personal safety from the hazard of smoke in building fires,it is necessary to keep escape routes clear of smoke or to keep the smoke concentration on the routes thinner than allowable one until the evacuation of the occupants is completed safely. For this, it is naturally required to control smoke movement by some means. There should be a need for some design system, so called 'smoke protection design system", to plan the reasonable and effective system suitable for every building to secure occupants from the hazard of smoke. Some calculation to estimate smoke movement or to evaluate smoke control methods will be indispensable to the design system.

Smoke movement is, needless to say, substantially caused by stack and wind actions the same way as air flow in a building. The movement is, therefore,practically under the influence of such conditions and factors as burning severity in fire compartment, composition of vertical shafts and other various flow paths and openings, temperatures on each part of a building and the outside air, the air handling systems involving the smoke tower or the pressurization method, and the outside wind. If these data are given, calculation of smoke movement can be made using a digital computer.

This paper presents a fundamental concept of the smoke protection design system, computer techniques for calculating smoke movement and computed results of sample buildings. A computer program has been formulated to calculate mass rate of smoke or air flowing through each path or opening and concentration of smoke and to evaluate methods of controlling smoke movement under various conditions for various buildings.

Key Words: Air, building, computer, concentration, control, design,density, escape, evacuation, fire, flow, movement, path, pressure,rate, shaft, smoke, stack action, wind action.

* Manuscript received on January 18, 1971.
** Research Member of Building Research Institute, Ministry of Construction