These parameters define the substance being burned, the type of fire (smoldering or flaming), and the sign illumination type for Smoke Visibility simulations:
The extinction coefficient characterizes the mode of combustion:
Type of Combustion |
Specific Extinction Coefficient (ft2/lbm) |
Smoldering combustion |
21000 |
Flaming combustion |
37000 |
The sign visibility constant characterizes the visibility of the sign:
Type of Situation |
Constant |
Illuminated sign |
8 |
Reflecting sign |
3 |
Building components in reflected light |
3 |
The combustion particulate yield is the particulate content of the smoke based on the burning fuel. It is an important parameter for characterizing the translucency of the smoke.
Combustible Material |
Particulate Yield |
Wood (red oak) |
0.015 |
Wood (Douglas fir) |
0.018 |
Wood (hemlock) |
0.015 |
Fiberboard |
0.008 |
Wool (100%) |
0.008 |
Acrylonitrile-Butadiene-Styrene (ABS) |
0.105 |
Polymethylemathacrylate (PMMA; PlexiglasTM) |
0.022 |
Polypropylene |
0.059 |
Polystyrene |
0.164 |
Silicone |
0.065 |
Polyester |
0.09 |
Nylon |
0.075 |
Silicone Rubber |
0.078 |
Polyurethane Foam (Flexible) |
0.188 |
Polyurethane Foam (Rigid) |
0.118 |
Polystyrene Foam |
0.194 |
Polyethylene Foam |
0.076 |
Phenolic Foam |
0.002 |
Polyethylene (PE) |
0.06 |
Polyvinylchloride (PVC) |
0.172 |
Ethylenetetrafluoroethylene (ETFE; TefzeTM) |
0.042 |
Perfluoroalkoxy (PFA; TeflonTM) |
0.002 |
Fluorinated Polyethylene-Polypropylene (FEP; TeflonTM) |
0.003 |
Tetrafluoroethylene (TFE; TeflonTM) |
0.003 |