20
A
LTERNATE
C
OMBUSTION
A
IR
P
ROVISION
(Upflow / Horizontal models only)
When using the alternate venting location, either in a
horizontal left side down installation or a vertical instal-
lation using down – venting, an alternate combustion air
opening can used. A locating dimple is located on the
right side of the furnace cabinet. The locating dimple is 1
7/8" measured from the front edge of the cabinet in line
with the knock out. To use the alternate combustion air
location:
1. Remove screws and combustion air flange from
cabinet.
2. Insert cabinet plug in unused combustion air hole.
3. Drill a pilot hole at the cabinet dimple (size dictated
by knockout tool used).
4. Use a knockout tool to create a 3" diameter hole
5. Install combustion air flange and secure with screws
removed in step one.
V
ENT
/F
LUE
P
IPE
L
ENGTHS
AND
D
IAMETERS
For installations at or above 7,000 feet altitude, use 3” vent-
ing. Refer to the following table for applicable length, elbows,
and pipe diameter for construction of the vent/flue pipe system.
The tee used in the vent/flue termination must be counted as
an elbow when determining the number of elbows in the piping
system.
1
2
3
4
5
6
7
8
2 or 2 1/2
115
110
105
100
95
90
85
80
3
137
130
123
116
109
102
95
88
2 or 2 1/2
115
110
105
100
95
90
85
80
3
147
140
133
126
119
112
105
98
2 or 2 1/2
60
55
50
45
40
35
30
25
3
120
113
106
99
92
85
78
71
2 or 2 1/2
40
35
30
25
20
15
10
5
3
144
137
130
123
116
109
102
95
2 or 2 1/2
40
35
30
25
20
15
10
5
3
144
137
130
123
116
109
102
95
2 or 2 1/2
95
90
85
80
75
70
65
60
3
144
137
130
123
116
109
102
95
2 or 2 1/2
95
90
85
80
75
70
65
60
3
144
137
130
123
116
109
102
95
2 or 2 1/2
60
55
50
45
40
35
30
25
3
120
113
106
99
92
85
78
71
2 or 2 1/2
40
35
30
25
20
15
10
5
3
103
96
89
82
75
68
61
54
DC97MC1005CNA*
DM97MC0804CNA*
DM97MC1005CNA*
DM97MC1205DNA*
DC97MC0603BNA*
DC97MC0803BNA*
DC97MC0804CNA*
DM97MC0803BNA*
Direct Vent (2 - Pipe) and Non-Direct Vent (1- Pipe)
(6)
Model
Pipe Size
Number of Elbows
DM97MC0603BNA*
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. elbows should be
considered equivalent to one 90 deg. elbow.
6) One 90° elbow should be secured to the combustion air intake connec-
tion.
7) For installations at or above 7,000 feet altitude, use 3” venting.
V
ENT
/F
LUE
P
IPE
T
ERMINATIONS
NOTE: If either a 90 degree or 45 degree elbow is used for
termination, it must be pointed downward.
The vent/flue pipe may terminate vertically, as through a
roof, or horizontally, as through an outside wall.
Vertical vent/flue pipe terminations should be as shown in
the following figure. Refer to
Vent/Flue Pipe and Combustion
Air Pipe - Termination Locations
for details concerning loca-
tion 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.
Horizontal vent/flue pipe terminations should be as shown in the
following figure. Refer to
Vent/Flue Pipe and Combustion Air
Pipe - Termination Locations
for details concerning location re-
strictions. The wall penetration should be sealed with sili-
cone caulking material.
NOTE: Terminate both pipes in
the same pressure zone
(same side of roof, no major obstacles between pipes,
etc.).
COMBUSTION AIR INTAKE
(OPTIONAL)
*Not requ ired for
singl e pipe installation
TEE (OPTIONAL)
96
” M
AX
. -
3”
MI
N.
RO
OF
LIN
E
12” MIN
HEIGHT DIFFERENCE
BETWEEN
INTAKE AND VENT
12” MIN TO ROOF OR HIGHEST
ANTICIPATED SNOW LEVEL
Figure 13
STRAIGHT
ELBOWS
Figure 14
