25
24 in.
Min.*
*Consult the NFPA ANSI Z223.1 Gas Vent Termination criteria if roof pitch exceeds 9:12
Sidewall Venting
Guidelines:
Vent Pipe Angle
• To prevent moisture from entering the heater system, slope the vent pipe down toward the outlet
1/4 in. per foot of length.
Do not
pitch the heater.
• **Vent must extend beyond any combustible overhang if the vent is less than 36 in. below the
combustible overhang.
Vent Cap
Single-wall Vent Pipe
Storm Collar
Adjustable Roof Flashing
Double-Wall B Vent
Roof*
Figure 3.21
•
General Vent Requirements
B to C Adapter
Heater
1 in. Minimum Clearance
1 in. Minimum Clearance
Fire Stop Spacer
3.0
Installation
•
Venting
•
Sidewall Venting
Single-Wall Elbow or Alternate Tee Fitting
#8 Sheet Metal Screws
Single-wall Vent Pipe
36 in.
min.**
Figure 3.22
•
Sidewall Venting Requirements
Building Overhang
Sidewall
Double-Wall
B-Vent
Single
Wall Vent
Wall Thimble
Sidewall Vent Cap
6 in.
min.**
B to C Adapter
Heater
1/4 in. downward
pitch per foot
