3 pipe diameter and length, 4 joints and sealing, 0 venting and combustion air requirements (cont’d) – Reznor UDBS Option - Installation - Separated Combustion Venting User Manual
Page 4
Form I-UD-V-SC, PN195676R17, Page 4
Applies to: Residential or Commercial/Industrial Installation
NOTE: Only UDAS 30, 45, 60, 75, 100, and 125 are certified for residential use.
Diameters of the
outside (terminal) concentric pipes are listed in TABLE 3.
1.3 Pipe Diameter and
Length
Pipe diameter and length requirements listed in
TABLE 2 are for the indoor sections
of pipe between the heater and the concentric adapter box.
Pipe diameters and maximum indoor vent lengths in
TABLE 2 apply to both horizon-
tal and vertical vent/combustion air systems. Add all straight sections and equivalent
lengths for elbows.
The total length of the straight sections and elbows must not
exceed the Maximum Length.
TABLE 2 - Pipe
Diameter and Length
from Heater to
Concentric Adapter
Box
• Minimum length
between the heater and
the concentric adapter
box is 1 ft (305mm)
for Sizes 30-125 and
3 ft (914mm) for Sizes
150-400.
1.4 Joints and Sealing
Provide pipes as specified in
Requirement No. 1.1, page 3, and seal joints as follows:
• To join sections of Category III pipe, follow the pipe manufacturer’s instructions
for joining and sealing.
• To join sections of single-wall pipe (vent pipe or combustion air pipe), secure
slip-fit pipe connections using sheetmetal screws or rivets. Seal all joints with
aluminum tape or silicone sealant.
• When joining the terminal section of double-wall vent pipe (vertical vent
terminal Option CC2 only) to the vent cap, follow the illustrated step-by-step
instructions in
FIGURE 2.
When joining a terminal section of double-wall vent pipe to a single-wall a
vent pipe run, follow the illustrated step-by-step instructions in FIGURE 3.
When joining two sections of double-wall vent pipe, follow the pipe
manufacturer’s instructions for joining and sealing vent pipe sections.
NOTE: Joints connecting
double-wall pipe apply
only to a vertical vent
terminal (Option CC2
Vertical Vent/Combustion
Air Kit). See Type of Pipe
requirement on page 3.
UDAS and UDBS
30, 45, 60, 75, 100, 125
150, 175, 200, 225, 250, 300, 350, 400
Inlet Air Pipe Diameter
6” (152mm)
8” (203mm)
Vent Pipe Diameter
4” (102mm)
5” (127mm)
Pipe Diameter and Maximum Length from Heater to Concentric Adapter Box
UDAS
and
UDBS
Pipe Diameter
Maximum
Length
Equivalent Straight Length for a
Vent Pipe Inlet Air Pipe
90° Elbow
45° Elbow
inches mm inches mm
feet
M
feet
M
feet
M
30
3
76
3
76
15
4.6
2
0.6
1
0.3
4
102
4
102
10
3.0
2
0.6
1
0.3
45
3
76
3
76
15
4.6
2
0.6
1
0.3
4
102
4
102
10
3.0
2
0.6
1
0.3
60
3
76
3
76
25
7.6
3
0.9
1.5
0.5
4
102
4
102
15
4.6
1.5
0.5
1
0.3
75
4
102
4
102
25
7.6
3
0.9
1.5
0.5
100
4
102
4
102
35 10.7
4
1.2
2
0.6
125
4
102
4
102
35 10.7
4
1.2
2
0.6
150
5
127
6
152
30
9.1
3
0.9
1.5
0.5
175
5
127
6
152
30
9.1
3
0.9
2
0.5
200
5
127
6
152
40 12.2
4
1.2
2
0.6
225
5
127
6
152
40 12.2
4
1.2
2
0.6
250
5
127
6
152
40 12.2
4
1.2
2
0.6
300
6
152
6
152
45 13.7
4
1.2
2
0.6
350
6
152
6
152
45 13.7
5
1.5
2.5
0.8
400
6
152
6
152
45 13.7
5
1.5
2.5
0.8
The outdoor pipe lengths depend on the installation; requirements are listed in the installation instructions for the hori-
zontal (Option CC6) and vertical (Option CC2) vent/combustion air kits.
TABLE 3 - Diameters
of Concentric (outdoor)
Pipes
1.0 Venting and Combustion Air Requirements (cont’d)