Advertisement
Altitude
FT (M)
Unit Size
BTU/Hr
Table 15 - Maximum
Equivalent
Vent Length
0 to 4500 Ft. (0 to 1370 M) Altitude
NOTE:
Maximum
Equivalent
Vent Length
(MEVL)
includes" standard
and concentric
vent termination
and does" NOT
include
elbows.
Use Table 16 -Deductions
from Maximum
Equivalent
Vent Length
to determine
allowable
vent length for each application.
DIRECT VENT (2-PIPE) AND NON-DIRECT
VENT (1 -PIPE)
Vent Pipe Diameter (in,)
100,000
0 to 2000
(0 to 61 O)
120,000
140,000"
100,000
2001
to 3000
(610 to 914)
120,000
140,000"
100,000
3001
to 4000
(914 to 1219)
120,000
140,000"
100,000
4001
to 4500
(1219
to 1370)
120,000
140,000"
NOTES: See notes at end of venting tables.
See Table 17 for altitudes over 4500 ft. (1370 M)
2
2-1/2
20
(6.1)
65
(19.8)
15
(4.6)
17
(5.2)
58
(17.7)
11
(3.4)
13
(4.0)
52
(15.8)
8
(2.4)
11
(3.4)
49
(14.9)
ELBOW CONFIGURATIONS
Long
Medium
Mitered
3
205
1O0
20
188
93
13
170
86
6
161
83
(62.5)
265
(30.5)
250
(8.1)
90
(57.3)
250
(28.3)
237
(4.0)
68
(51.8)
236
(26.2)
224
(1.8)
46
(49.1)
229
(25.3)
217
35
4
(80.8)
(76.2)
(27.4)
(76.2)
(72.2)
(20.7)
(71.9)
(68.3)
(14.0)
(69.8)
(66.1)
(10.7)
VENTTERMINAL
CONFIGURATIONS
©
Concentric
I___
__)')I
Standard
2-in., 3-in., or
optional
4-in. termination.
A13110
Table
16 - Deductions
from
Maximum
Equivalent
Vent Length
Pipe Diameter (in):
2
2-1/2
3
4
Mitered 90 ° Elbow
8
(2.4)
8
(2.4)
8
(2.4)
8
(2.4)
Medium Radius 90 ° Elbow
5
(1.5)
5
(1.5)
5
(1.5)
5
(1.5)
Long Radius 90 ° Elbow
3
(0.9)
3
(0.9)
3
(0.9)
3
(0.9)
Mitered 45 ° Elbow
4
(1.2)
4
(1.2)
4
(1.2)
4
(1.2)
Medium Radius 45 ° Elbow
2.5
(0.8)
2.5
(0.8)
2.5
(0.8)
2.5
(0.8)
Long Radius 45 ° Elbow
1.5
(0.5)
1.5
(0.5)
1.5
(0.5)
1.5
(0.5)
Tee
16
(4.9)
16
(4.9)
16
(4.9)
16
(4.9)
Venting System
Length
Calculations
The Total Equivalent
Vent Length (TEVL)
for EACH
combustion
air or vent pipe equals the length of the venting system,
plus the equivalent
length of elbows
used in the venting
system
from Table 16.
Standard
vent terminations
or factory
accessory
concentric
vent terminations
count
for zero deduction.
See vent system
manufacturer's
data for equivalent
lengths
of flexible
vent pipe or other termination
systems.
DO NOT
ASSUME
that one
foot of flexible
vent pipe equals one foot of straight
PVC/ABS
DWV vent pipe.
Compare
the Total Equivalent
Vent Length
to the Maximum
Equivalent
Vent Lengths
in Tables 15 and 17.
44
Advertisement
