Roof terminations-Loosely install pipe coupling on properly
cut vent pipe. Coupling must be positioned so bracket will
mount as shown in Fig. 37.
For applications using combustion-air pipe option, indicated
by dashed lines in Fig. 37, install 90° street elbow into 90°
elbow, making U-fitting. A 180° U-fitting may be used.
Sidewall terminations-Install bracket as shown in Fig. 40 or
41.
For applications using vent pipe option indicated by dashed
lines in Fig. 40, rotate vent elbow 90° from position shown in
Fig. 40.
4. Disassemble loose pipe fittings. Clean and cement using same
procedures as used for system piping.
5. Check required dimensions as shown in Fig. 37, 40, or 41.
Concentric Vent/Air Termination Kit
1. Determine location for termination. Consideration of the
following should be made when determining an appropriate
location for termination kit.
a. Comply with all clearance requirements as stated in Table
6.
b. Termination kit should be positioned where vent vapors
will not damage plants/shrubs or air conditioning equip-
ment.
c. Termination kit should be positioned so it will not be
affected by wind eddy (such as inside building corners) or
that may allow recirculation of flue gases, airborne leaves,
or light snow.
d. Termination kit should be positioned where it will not be
damaged by or subjected to foreign objects, such as stones,
balls, etc.
e. Termination kit should be positioned where vent vapors are
not objectionable.
2. Cut one 4-in. diameter hole for 2-in. kit, or one 5-in. diameter
hole for 3-in. kit.
3. Loosely assemble concentric vent/air termination components
together using instructions in kit.
4. Slide assembled kit with rain shield REMOVED through hole.
NOTE:
Do not allow insulation or other materials to accumulate
inside of pipe assembly when installing it through hole.
Roof terminations-Locate assembly through roof to appro-
priate height as shown in Fig. 38.
Sidewall terminations-Locate assembly through sidewall
with rain shield positioned no more than 1-in. from wall as
shown in Fig. 39.
TABLE 7—MAXIMUM ALLOWABLE PIPE LENGTH (FT) (Continued)
ALTITUDE (FT)
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
NUMBER OF 90° ELBOWS
1
2
3
4
5
6
8001 to 9000‡
060-12
2 Pipe or 2-in
Concentric
1-1/2
11
6
NA
NA
NA
NA
2
49
44
42
37
35
34
080-12
080-16
2 Pipe or 2-in
Concentric
2
33
28
17
12
10
NA
2-1/2
62
60
58
56
55
53
100-16
100-20
2 Pipe or 3-in
Concentric
2-1/2
23
15
7
5
NA
NA
3
59
54
49
44
39
34
120-20
2 Pipe or 3-in.
Concentric
3† no disk
10
NA
NA
NA
NA
NA
4† no disk
35
30
25
20
15
10
ALTITUDE (FT)
UNIT SIZE
TERMINATION
TYPE
PIPE DIA
(IN.)*
NUMBER OF 90° ELBOWS
1
2
3
4
5
6
9001 to 10,000‡
060-12
2 Pipe or 2-in
Concentric
2
45
40
38
33
31
29
080-12
080-16
2 Pipe or 2-in
Concentric
2
30
25
14
9
7
NA
2-1/2
57
55
53
51
49
47
100-16
100-20
2 Pipe or 3-in
Concentric
2-1/2
21
13
5
NA
NA
NA
3
54
49
44
39
34
29
120-20
2 Pipe or 3-in.
Concentric
4† no disk
10
5
NA
NA
NA
NA
* Disk usage-Unless otherwise specified, use perforated disk assembly (factory-supplied in loose parts bag). If one disk is stated, separate 2 halves of perforated disk
assembly and use shouldered disk half. When using shouldered disk half, install screen side toward inlet box.
† Wide radius elbow.
‡ Vent sizing for Canadian installations over 4500 ft (1370 m) above sea level are subject to acceptance by the local authorities having jurisdiction.
NA-Not Allowed; pressure switch will not make.
NOTES:
1. Do not use pipe size greater than those specified in table or incomplete combustion, flame disturbance, or flame sense lockout may occur.
2. Size both the combustion-air and vent pipe independently, determine the smallest diameter allowed by the chart for each pipe, then use the larger of these two
diameters for both pipes.
3. Assume two 45° elbows equal one 90° elbow. Long radius elbows are desirable and may be required in some cases.
4. Elbows and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
5. The minimum pipe length is 5 ft for all applications.
6. Use the 3-in. diameter vent termination kit for installations requiring 4-in diameter pipe.
Fig. 36—Air Intake Housing Plug Fitting Drain
A93035
COMBUSTION –
AIR PIPE
BURNER
BOX
COMBUSTION – AIR
INTAKE HOUSING
3/8" ID TUBE
TRAP
TO OPEN
DRAIN
3/16"
DRILL
4
″
MIN
32
