User's Manual

Design
P/N 81-CO2MAN-001 3-7 September 2013
3-5.2.2.1 Ducts and Covered Trenches
A flooding factor of 8
ft.
3
/lb. (0.50 m
3
/kg), or 0.125 lb./ft.
3
(2.00 kg/m
3
), must be used when
total flooding a duct or a covered trench. This results in a concentration of 65% and does not
require the use of a Material Conversion Factor (see Paragraph 3-5.2.3). If the accumulation
of combustibles on the wall of the duct or trench creates a deep-seated hazard, the system
must be designed according to the criteria specified in Paragraph 3-5.3.
Table 3-2B. Volume Factors - Surface Fires (For 34% CO
2
Concentration), Metric Units
Enclosure Volume (m
3
)
Volume Factor
Calculated Quantity
(m
3
/kg) (kg/m
3
)
Not Less Than (kg)
Up to 3.96 .086 1.15 --
3.97 - 14.15 .093 1.07 4.5
14.16 - 45.28 0.99 1.01 15.1
45.29 - 127.35 1.11 0.90 45.4
127.36 - 1415.0 1.25 0.80 113.5
Over 1415.0 1.38 0.77 1135.0
Ducts and Covered Trenches
(See Section 3-5.2.2.1)
0.50 2.00 --
EXAMPLE 1 - TOTAL FLOODING FOR SURFACE FIRES - Basic Carbon Dioxide Quantity
Consider a room with dimensions of 20 ft. by 30 ft. by 10 ft. . Determine the
basic carbon dioxide quantity.
From Equation (1):
Where is Volume Of The Protected Space and
is the Volume Factor.
=20 ft. x 30 ft. x 10 ft.
=6,000
ft.
3
=20 ft.
3
/lb. from Table 3-2 for volumes 4,501 ft.
3
to 50,000 ft.
3
f
1
f
2
L
W
H
W
B
Vf
1
=
V
f
1
V
V
f
1
W
B
Vf
1
=
W
B
6000 20=
W
B
300lb=