5 Vertical direct venting
Vent/air termination – vertical
WARNING Follow instructions below when determining vent location to avoid
possibility of severe personal injury, death or substantial property damage.
Installation & Operation Manual
Figure
ALTERNATE INTAKE LOCATIONS:
INTAKE PIPES MAY BE LOCATED
ANYWHERE WITHIN 24” OF VENT
PIPE
Determine location
Locate the vent/air terminations using the following guidelines:
1. | The total length of piping for vent or air must not exceed |
| the limits given in the General Venting Section on page |
| 16 of this manual. |
2. | Prepare the vent termination and the air termination |
| elbow (FIG. |
| should be obtained locally. |
3. | The vent must terminate at least 3 feet above the highest |
| place in which the vent penetrates the roof and at least |
| 2 feet above any part of a building within 10 horizontal |
BIRD SCREEN (TYPICAL)
COUPLING (FIELD SUPPLIED)
VENT OUTLET
12” MINIMUM ABOVE AIR INLET
VENT
6” MINIMUM ABOVE ROOF / SNOW LINE
COMBUSTION
AIR
feet. |
4. The air piping must terminate in a |
return pipe no further than 2 feet from the center of the |
Figure
vent pipe. This placement avoids recirculation of flue |
products into the combustion air stream. |
5. The vent piping must terminate in an |
as shown in FIG. |
be at least 1 foot above the air intake. When the vent |
termination uses a rain cap as illustrated in FIG. |
maintain at least 36" (914 mm) above the air inlet. The |
air inlet pipe and vent pipe can be located in any desired |
position on the roof, but must always be no further than |
ALTERNATE INTAKE LOCATIONS: INTAKE PIPES MAY BE LOCATED ANYWHERE WITHIN 24” (610 MM)
OF VENT PIPE
VENT
BIRD SCREEN
(TYPICAL)
2 feet (.6 m) apart and with the vent termination at least |
1 foot for PVC and 3 feet for stainless steel, above the air |
intake. |
6. Maintain the required dimensions of the finished |
termination piping as shown in FIG. |
7. Do not extend exposed vent pipe outside of building |
more than shown in this document. Condensate could |
freeze and block vent pipe. |
WARNING Rooftop vent and air inlet terminations |
must terminate in the same pressure |
zone, unless vertical vent sidewall air is set up as shown in the General Venting - Vertical Vent, Sidewall Air Section.
6" (152 MM) MINIMUM
ABOVE ROOF /
SNOW LINE
COM,BUSTION
AIR
VENT OUTLET
36” (914 MM) MINIMUM
ABOVE AIR INLET
8.Locate terminations so they are not likely to be damaged by foreign objects or subject to buildup of leaves or sediment.
Prepare roof penetrations
1.Air pipe penetration:
a.Cut a hole for the air pipe. Size the air pipe hole as close as desired to the air pipe outside diameter.
2.Vent pipe penetration:
a.Cut a hole for the vent pipe. For either combustible or noncombustible construction, size the vent pipe hole with at least a 1/2 inch clearance around the vent pipe outer diameter:
•3½ inch hole for 2 inch vent pipe
•4½ inch hole for 3 inch vent pipe
b.Insert a galvanized metal thimble in the vent pipe hole.
29 
