Where alternative venting systems are used in lieu of the requirements of Section 2209.5.4.3.5, an analysis of radiant heat exposures and hydrogen concentrations shall be provided. The analysis of exposure to radiant heat shall assume a wind speed of 30 feet/second (9.14 m/sec) and provide a design that limits radiant heat exposure to the maximum values shown in Table 2209.5.4.3.6(1). The analysis of exposure to hydrogen concentration shall provide a design that limits the maximum hydrogen concentration to the values shown in Table 2209.5.4.3.6(2).
TABLE 2209.5.4.3.6(1) MAXIMUM RADIANT HEAT EXPOSURE
TABLE 2209.5.4.3.6(2) MAXIMUM HYDROGEN CONCENTRATION EXPOSURE
TABLE 2209.5.4.3.6(1) MAXIMUM RADIANT HEAT EXPOSURE
| EXPOSED OBJECT | MAXIMUM RADIANT HEAT | TIME DURATION (minutes) |
| Personnel | 1,500 Btu/hr • ft2 (4732 W/m2) | 3 |
| Noncombustible equipment | 8,000 Btu/hr • ft2 (25 237 W/m2) | Any |
| Lot line | 500 Btu/hr • ft2 (1577 W/m2) | Any |
TABLE 2209.5.4.3.6(2) MAXIMUM HYDROGEN CONCENTRATION EXPOSURE
| EXPOSED OBJECT | MAXIMUM HYDROGEN CONCENTRATION |
| Personnel, buildings or equipment | 50% LFL within a distance of D and H of Table 2209.5.4.3.4 |
| Lot line | 50% LFL within 1.25 times the distance of D and H of Table 2209.5.4.3.4 |