Installation & Operation Manual
24
5
Vertical direct venting
Vent/air termination – vertical
Follow instructions below when
determining vent location to avoid
possibility of severe personal injury, death
or substantial property damage.
Installation must comply with local
requirements and with the National Fuel
Gas Code,
ANSI Z223.1 for U.S.
installations or CSA B149.1 or B149.2 for
Canadian installations.
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.
The air piping must terminate in a down-turned 180°
return pipe no further than 2 feet from the center of the
vent pipe. This placement avoids recirculation of flue
products into the combustion air stream.
3.
The vent piping must terminate in an up-turned coupling
as shown in FIG. 34. The top of the coupling must be at
least 1 foot above the air intake. The air inlet pipe and
vent pipe can be located in any desired position on the
roof, but must always be no further than 2 feet apart and
with the vent termination at least 1 foot above the air
intake.
4.
You must consider the surroundings when terminating
the vent and air:
a.
Position the vent termination where vapors will not
damage nearby shrubs, plants, or air conditioning
equipment or be objectionable.
b.
The flue products will form a noticeable plume as
they condense in cold air. Avoid areas where the
plume could obstruct window views.
c.
Prevailing winds could cause freezing of condensate
and water/ice buildup where flue products impinge
on building surfaces or plants.
d.
Avoid possibility of accidental contact of flue
products with people or pets.
Figure 34
Vertical Termination of Air and Vent
5.
Maintain clearances to vent termination as given in
FIG. 34:
a.
Vent must terminate:
• At least 6 feet from adjacent walls.
• No closer than 5 feet below roof overhang.
• At least 7 feet above any public walkway.
• At least 3 feet above any forced air intake within
10 feet.
• No closer than 12 inches below or horizontally
from any door or window or any other gravity air
inlet.
b.
Air inlet must terminate at least 6 inches above the
roof or snow line and at least 12 inches below the
vent termination as shown in FIG. 34.
c.
Do not terminate closer than 4 feet horizontally
from any electric meter, gas meter, regulator, relief
valve, or other equipment. Never terminate above or
below any of these within 4 feet horizontally.
6.
Locate terminations so they are not likely to be damaged
by foreign objects, such as stones or balls, or subject to
buildup of leaves or sediment.
WARNING
NOTICE
WARNING
Do not connect any other appliance to the
vent pipe or multiple boilers to a common
vent pipe. Failure to comply could result in
severe personal injury, death, or substantial
property damage.
e.
Do not locate the terminations where wind eddies
could affect performance or cause recirculation,
such as inside building corners, near adjacent
buildings or surfaces, window wells, stairwells,
alcoves, courtyards, or other recessed areas.
f.
Do not terminate above any door or window.
Condensate can freeze, causing ice formations.
g.
Locate or guard vent to prevent condensate damage
to exterior finishes.
