SYSTEM OPERATION
14
*M9S9 / *C9S9 Direct Vent (2-Pipe) & Non-Direct Vent (1-Pipe)
(6)
Maximum Allowable Length of Vent/Flue Pipe
MODEL
PIPE
SIZE
1
2
3
4
5
6
7
8
2^
108
105
101
97
93
90
86
82
3
126
120
115
110
105
99
94
89
2
55
50
45
40
35
30
25
20
3
127
120
113
106
99
92
85
78
2
30
25
20
15
10
5
N/A
N/A
3
72
65
58
51
44
37
30
23
2
30
25
20
15
10
5
N/A
N/A
3
72
65
58
51
44
37
30
23
2
40
35
30
25
20
15
10
5
3
72
65
58
51
44
37
30
23
2
60
55
50
45
40
35
30
25
3
168
161
154
147
140
133
126
119
2
30
25
20
15
10
5
N/A
N/A
3
113
106
99
92
85
78
71
64
2
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
3
65
58
51
44
37
30
23
16
MODEL
PIPE
1
2
3
4
5
6
7
8
2^
75
71
67
63
60
56
52
48
3
126
120
115
110
105
99
94
89
2
45
40
35
30
25
20
15
10
3
168
161
154
147
140
133
126
119
2
35
30
25
20
15
10
5
N/A
3
168
161
154
147
140
133
126
119
2
60
55
50
45
40
35
30
25
3
113
106
99
92
85
78
71
64
2
45
40
35
30
25
20
15
10
3
120
113
106
99
92
85
78
71
2
40
35
30
25
20
15
10
5
3
151
144
137
130
123
116
109
102
2
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
3
158
151
144
137
130
123
116
109
2
100
95
90
85
80
75
70
65
3
137
130
123
116
109
102
95
88
2
45
40
35
30
25
20
15
10
3
168
161
154
147
140
133
126
119
2
40
35
30
25
20
15
10
5
3
120
113
106
99
92
85
78
71
2
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
3
113
106
99
92
85
78
71
64
2
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
3
110
103
96
89
82
75
68
61
*M9S920403AN
Number of Elbows
(3) (5)
*M9S920603BN
*M9S960403AN
*M9S960803BN
*M9S960804BN
*M9S960603BN
*M9S920803BN
*M9S920804CN
*M9S920805CN
*M9S921004CN
*M9S921005CN
*M9S921205DN
*M9S960805CN
*M9S961005CN
*C9S961005CN
*C9S961205DN
*M9S961205DN
*C9S960403BN
*C9S960603BN
*C9S960804CN
1. Maximum allowable limits listed on individual lengths for inlet and
flue and NOT a combination.
2.
Minimum requirement for each vent pipe is five (5) feet in length
and one elbow/tee.
3.
Tee used in the vent/flue termination must be included when deter
-
mining the number of elbows in the piping system.
4.
2 1/2” or 3” diameter pipe can be used in place of 2” diameter pipe.
5.
Increased Clearance Configurations using (2) 45 deg. Long Sweep
elbows should be considered equivalent to one 90 deg. elbow.
6. One 90° elbow should be secured to the combustion air intake
connection.
Vent/Flue and Combustion Air Pipe Lengths
and Diameters
Refer to the preceding table for applicable length, elbows,
and pipe diameter for construction of the vent/flue and com
-
bustion air intake pipe systems of a non-direct vent (single
pipe) installation. The number of elbows tabulated rep-
resents the number of elbows and/or tees in each (Vent/Flue
& Combustion Air Intake) pipe. Elbows and/or tees used in
the terminations must be included when determining the
number of elbows in the piping systems.
If the combustion air intake pipe is to be installed above a
finished ceiling or other area where dripping of condensate
will be objectionable, insulation of the combustion air pipe
may be required. Use 1/2” thick closed cell foam insulation
such as Armaflex or Insultube where required.
Vent/Flue Pipe Terminations
The vent/flue pipe may terminate vertically, as through a
roof, or horizontally, as through an outside wall.
Vertical vent/flue pipe termination should be as shown in the
following figures. Refer to
Vent/Flue Pipe and Combustion
Air Pipe - Termination Locations
section in this manual or
the installation instructions for details concerning location
restrictions. The penetration of the vent through the roof
must be sealed tight with proper flashing such as is used
with a plastic plumbing vent.
NOTE:
Terminate both pipes in the same pressure zone
(same side of roof, no major obstacles between pipes, etc.).
R
OOF
LIN
E
COMBUSTION AIR INTAKE
(OPTIONAL)
*Not required for
single pipe installation
TEE (OPTIONAL)
96
”
MA
X
.
- 3
”
MIN
.
12” MIN
HEIGHT DIFFERENCE
BETWEEN
INTAKE AND VENT
12” MIN TO ROOF OR HIGHEST
ANTICIPATED SNOW LEVEL
STRAIGHT
ELBOWS
Horizontal vent/flue pipe terminations should be as shown
in the following figure. Refer to
Vent/Flue Pipe and Combus-
tion Air Pipe - Termination Locations
section in this manual
or the installation instructions for details concerning location
restrictions. A 2 3/8” diameter wall penetration is required for
2” diameter pipe while a 3 1/2” diameter hole is required for
3” diameter pipe. To secure the pipe passing through the
wall and prohibit damage to piping connections, a coupling
should be installed on either side of the wall and solvent
cemented to a length of pipe connecting the two couplings.
The length of pipe should be the wall thickness plus the
depth of the socket fittings to be installed on the inside and
outside of the wall. The wall penetration should be sealed
with silicone caulking material.
