3
General venting
16
Installation & Service Manual
Minimum / Maximum allowable combustion
air and vent piping lengths are as follows:
Combustion Air
= 7 equivalent feet minimum / 100 equivalent
feet maximum
Vent
= 7 equivalent feet minimum / 100 equivalent feet
maximum
When determining equivalent combustion air and vent length,
add 5 feet for each 90° elbow and 3 feet for each 45° elbow.
EXAMPLE:
20 feet of PVC pipe + (4) 90° (2) 45°
(1) concentric vent kit (CVK3003) = 49 equivalent
feet of piping.
The appliance output rating will reduce by
up to 1.5% for each 25 feet of vent length.
NOTICE
Model
Kit Number
Equivalent Vent
Length
40 - 100
CVK3008
3 feet
120
CVK3003
3 feet
Table 3B Concentric Vent Kit Equivalent Vent Lengths
Sizing
The Cadet boiler uses model specific combustion air intake
and vent piping sizes as detailed in Table 3A below.
Table 3A Air Intake/Vent Piping Sizes
Increasing or decreasing combustion air or
vent piping sizes is not authorized.
NOTICE
Model
2” Max Vent/Air 3” Max Vent/Air
40
100 feet
100 feet
70
100 feet
100 feet
100
50 feet
100 feet
120
N/A
100 feet
120 (C)
N/A
100 feet
