Vertical direct venting | Lochinvar WH 55-399 guide

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 5-1APVC/CPVC/Polypropylene Vertical Termination of Air and Vent

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. 5-1A) by inserting bird screens. Bird screens
	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 down-turned 180°

return pipe no further than 2 feet from the center of the

Figure 5-1BStainless Steel Vertical Termination of Air and Vent

vent pipe. This placement avoids recirculation of flue

products into the combustion air stream.

5. The vent piping must terminate in an up-turned coupling

as shown in FIG. 5-1A. The top of the coupling must

be at least 1 foot above the air intake. When the vent

termination uses a rain cap as illustrated in FIG. 5-1B

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. 5-1A.

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.