
Part number 550-100-086/0809
COMMERCIAL
GAS
-
FIRED
WATER
BOILER
—
Boiler Manual
40
DIRECT VENT — Sidewall
(continued)
Apply the configuration on the right side of
b.
Figure 35 when
the terminations need to be raised higher to meet clearance to
grade or snow line.
The vent and air pipes may run up as high as 4 feet, as shown in
c.
Figure 35 right side with no enclosure. The vent and air pipes
must be secured with braces, and all clearances and lengths
must be maintained. Space braces no further than 24 inches
apart. (See WARNING below for extremely cold climates.)
External venting greater than 4 feet requires an enclosure
d.
around the vent and air pipes. The vent and air terminations
must exit through the enclosure as shown in Figure 35, main-
taining all required clearances.
The vent piping must terminate in an elbow pointed outward or
3.
away from the air inlet, as shown in Figure 35.
Do not exceed the maximum lengths of the outside vent
piping shown in Figure 35. Excessive length exposed to
the outside could cause freezing of condensate in the vent
pipe, resulting in potential boiler shutdown. In extremely
cold climates, install an insulated chase around the vent
piping, particularly when using longer lengths. The chase
must allow for inspection of the vent pipe, and insulation
must be protected from water.
DIRECT VENT — Sidewall — configuration
&IGURE
options and minimum clearances from vent to air
terminations
Consider the surroundings when terminating the vent and air:
4.
Position the vent termination where vapors will not damage
a.
nearby shrubs, plants or air conditioning equipment or be
objectionable.
The flue products will form a noticeable plume as they con-
b.
dense in cold air. Avoid areas where the plume could obstruct
window views.
Sidewall termination with separate pipes
&IGURE
— clearances to openings
Sidewall termination with separate pipes
&IGURE
— clearances from vent exit to forced air
intake
Terminating with the vent elbow sideways
instead of pointed away from the building can
result in the possibility of ice build-up on the
side of the building.
If the vent/air pipes are extended out beyond
the wall, install a coupling at the exit opening,
with the coupling butted against the outside
plate. Then continue vent/air piping from the
coupling.