BFit BFITW 1000, Installation, Operation And Maintenance Manual

Page: 19 / 76

19
VII . Venting
(continued)
Table 7: Equivalent lengths of Vent and Combustion Air Components
Component
Combustion Air Vent
Equivalent
Length Per
Piece
x Quantity =
Subtotal
Equivalent
Length
Equivalent
Length
Per Piece
x Quantity =
Subtotal
Equivalent
Length
Straight Pipe x = A x = D
90° Elbow x = B x = E
45° Elbow x = C x = F
Combustion Air Total
Equivalent Length =
Vent Total
Equivalent Length
=
Notes:
1. Total equivalent length cannot exceed maximum equivalent length shown in Table 6.
2. Combustion air and vent terminations do not count towards total equivalent length.
Diameter 6 in. (160 mm) 8 in. (200 mm) 10 in. (250 mm) 12 in. (315 mm)
90
°
Elbow
7 ft. (2.1 m) 11 ft. (3.4 m) 14 ft. (4.3 m) 18 ft. (5.5 m)
45° Elbow 3 ft. (0.9 m) 4 ft. (1.2 m) 5 ft. (1.5 m) 7 ft. (2.1 m)
At Maximum Input Rate At Minimum Input Rate
BFIT
Model
Vent
Dia. (In.)
Flue Gas Flow,
ACFM @ 35%
Excess Air, 180
0
F
Combustion Air,
SCFM @ 35%
Excess Air, 60
0
F
Flue Gas Flow,
ACFM @ 35%
Excess Air, 180
0
F
Combustion Air,
SCFM @ 35%
Excess Air, 60
0
F
1000
8
282 212 56 42
1250 352 265 70 53
1500 423 318 84 63
2000 564 424 113 85
2500
10
705 531 141 106
3000 846 637 169 127
3500
12
987 743 197 148
4000 1129 849 225 170
Note: Flow rates are based on the combustion of natural gas.
Make Material Model
Heat Fab Stainless Steel Saf-T Vent EZ Seal*
Z-Flex (Nova Flex Group)
Stainless Steel/
Polypropylene
Z-Vent/Z-DENS
DuraVent Polypropylene PolyPro Single Wall Rigid
Centrotherm Polypropylene InnoFlue SW Rigid
*Factory supplied flue connection. Adapters are required to transition to alternate vent
materials or manufacturers.
Table 8: Vent and Combustion Air Equivalent Length Calculation Worksheet
Table 9: Flue Gas and Combustion Air Flow Rates
Table 10: Approved Vent Manufacturers and Materials