Sizing; Max. Allowable Vent Piping Lengths - Cadet 40-120 Installation And Service Manual

3
General venting

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
Model 2" Max Vent/Air 3" Max Vent/Air
40 100 feet
70 100 feet
100 50 feet
120 N/A
120 (C) N/A
Increasing or decreasing combustion air or
NOTICE
vent piping sizes is not authorized.
16
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.
100 feet
100 feet EXAMPLE: 20 feet of PVC pipe + (4) 90° elbows + (2) 45°
elbows + (1) concentric vent kit (CVK3003) = 49 equivalent
100 feet
feet of piping.
100 feet
100 feet
NOTICE
Table 3B Concentric Vent Kit Equivalent Vent Lengths
Model
40 - 100
120
Installation & Service Manual
The appliance output rating will reduce by
up to 1.5% for each 25 feet of vent length.
Equivalent Vent
Kit Number
Length
CVK3008
CVK3003
3 feet
3 feet