54
Rev.12/31/97
So the fan must clear the room before the hydrogen generation can produce
148.3 cubic feet of hydrogen. This production is 0.794 cubic foot per
minute, so:
148.3 cubic feet of hydrogen. This production is 0.794 cubic foot per
minute, so:
148.3 ft
3
÷ 0.794 ft
3
/min = 186.7 min to clear the room before H
2
volume is
produced
The total room volume is 18,538 ft
3
, so:
18,538 ÷ 186.7 = 99.29-ft
3
/min fan capacity
Fans are rated in hundreds of cubic feet per minute, so at least a 100-cubic-
foot-per-minute fan is needed.
foot-per-minute fan is needed.
Another way to calculate this fan size would be that the fan must move 0.8
percent of the total volume of the room each minute. So divide the
hydrogen production rate by 0.8 percent to give the total fan capacity.
hydrogen production rate by 0.8 percent to give the total fan capacity.
0.794 ft
3
/min ÷ 0.008 = 99.25 ft
3
/min
8.5 BATTERY ROOMS
8.5 BATTERY ROOMS
Battery rooms in future and remodeled facilities are to be designed,
constructed, and maintained in accordance with section 14--Storage
Batteries--of the National Electrical Safety Code. Battery systems now
located in control buildings or powerplants need not be placed in a separate
room. However, when not located in a separate room, barriers or some type
of mechanical protection must be provided to prevent inadvertent personnel
or equipment contact and resultant damage. Periodic air flow
measurements and explosion meter (total combustible gas) readings are
recommended in the general battery areas to ensure adequate air movement
to diffuse generation of hydrogen gas.
constructed, and maintained in accordance with section 14--Storage
Batteries--of the National Electrical Safety Code. Battery systems now
located in control buildings or powerplants need not be placed in a separate
room. However, when not located in a separate room, barriers or some type
of mechanical protection must be provided to prevent inadvertent personnel
or equipment contact and resultant damage. Periodic air flow
measurements and explosion meter (total combustible gas) readings are
recommended in the general battery areas to ensure adequate air movement
to diffuse generation of hydrogen gas.
"No Smoking," "No Sparks," or "No Open Flame" signs should be posted on
the outside of the door.
the outside of the door.
Seismic protection should be provided in areas with high seismic activity.
Metal battery racks shall be grounded.
Concrete floors shall be painted with acid-resistive paint (alkaline resistive)
for ni-cad batteries.
for ni-cad batteries.
Electrical receptacles and light switches should be located outside of battery
areas.
areas.
A 10-pound class C fire extinguisher should be located just inside the battery
room door. The fire extinguisher should not be a CO
room door. The fire extinguisher should not be a CO
2
type to prevent
thermal shock to the battery.