A test rig, consisting of a room communicating with a corridor, has been oconstructed for examining the products of combustion arising from fires in the compartment or corridor. Tests with wood fuel have shown that thermally reproducible fires are obtained from a given weight of fuel in the oompartment and a given arrangement of ventilation.
Under the conditions of ventilation used, the smoke produced from relatively small loads of wood (14.5 to 29 kg/m2) was sufficiently dense to impede escape, even when the smoke and fire gases were diluted with cool air to a temperature that could be borne for a short time during which an attempt to escape could be made.
The concentration of the principal toxio gas, carbon monoxide, in the fire gases is primarily dependent upon the weight of the fire load of wood. Dilution of the fire gases with cool air to a temperature that could be borne for a short time during escape produced atmospheres with fire gases from the greater weight of wood that were hazardous for short exposure, whereas those from the lesser weights were not so.
The produotion of carbon monoxide from the tests with the greatest degree of ventilation examined rose and fell simply during fires, whereas tests with the lesser degrees of ventilation resulted in periodic variations in concentration. The former test condition is more amenable to variations in concerning toxio gas evolution.