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UEZ-IOM (07-23) 1034347-I
VENTING AND COMBUSTION AIR REQUIREMENTS—CONTINUED
Vent/Combustion Air System Piping Requirements—Continued
Vent/Combustion Air Piping Requirements (Unit Sizes 130–310)—Continued
Table 10. Vent/Combustion Air Piping Size Requirements (Unit Sizes 130–310)
Vent Piping Combustion Air Piping
Diameter
(Inches (mm))
Maximum
Length
Equivalent Straight
Length for Elbows
Pipe
Section
Diameter
(Inches (mm))
Length
(Feet (Meters))
90-Degree
Elbow*
45-Degree
Elbow
Feet (Meters) Minimum Maximum
4 (102)
50 (
15.2) 8 (2.4) 4 (1.2)
Heater to concentric
adapter box
6 (152)
3 (
914) Same as vent pipe
Concentric adapter
box to outdoors
8 (203) Refer to Vent Connections section
*All 90-degree elbows in the vent system must be sweep type.
NOTE: The minimum/maximum requirements for the length of vent pipe that extends outdoors are different for horizontal and vertical vent
terminals (refer to Vent Connections section).
Figure 5. Connections at Rear of Unit—Unit Sizes 130–310 (Refer to Table 11)
DISCONNECT
SWITCH
LINE VOLTAGE
ENTRANCE
COMBUSTION AIR
PIPE COLLAR
A
C
B
D
CONDENSATE DRAI
VENT PIPE
TERMINAL STRIP
Table 11. Connection Sizes and Locations (Unit Sizes 130–310)
Dimension (See Figure 5)
or Connection
Unit Size
130, 180 260, 310
Dimension/Diameter (Inches (mm))
A 8-1/4 (210)
B 3-1/4 (83)
C 8-5/16 (211) 9-3/32 (231)
D 4-5/16 (110) 5-1/16 (129)
Combustion air pipe collar 6 (153)
PVC vent pipe 4 (102)
PVC condensate drain pipe 1/2 (13)