Horizontal Thru-Wall Stack Vent Termination - CleaverBrooks CFC Operation, Service & Parts Manual

Care must be taken during assembly that all joints are sealed
properly and are airtight for both the combustion air intake and the
exhaust stack piping system.
The stack vent must be installed to prevent the potential
accumulation of condensate in the stack pipes. It is recommended
that:
• The vent be installed with a slope of at least 1/4" per foot of
horizontal run (direction of line pitch may be back to the boiler or
to the vent terminal).
• The vent be insulated through the length of the horizontal run.

2. Horizontal Thru-Wall Stack Vent Termination

The stack vent cap MUST be mounted on the exterior of the
building. The stack vent cap cannot be installed in a well or below
grade. The stack vent cap must be installed at least one (I) foot
above ground level and above normal snow levels.
Multiple stack vent caps should be installed in the same horizontal
plane with a three (3) foot clearance from the side of one stack cap
to the side of the adjacent stack vent cap(s).
Combustion air supplied from outside must be free of particulate
and chemical contaminants. To avoid a blocked flue condition, keep
all the vent caps clear of snow, ice, leaves, debris, etc.
If the boiler is vented directly out through the sidewall with no
elbows and less than 10 feet of vent pipe, a restricted direct vent
termination should be utilized. A well designed direct vent
termination should minimize the effect of adverse wind conditions
Caution
!
Multiple direct stack vent caps MUST NOT be installed with one
combustion air inlet directly above a stack vent cap. This vertical
spacing would allow the flue products from the stack vent cap to
be pulled into the combustion air intake installed above. This type
of installation can cause non warrantable problems with
components and poor operation of the unit due to the recirculation
of flue products.
Part No. 750-263
Section 3 — Stack and Intake Vent Sizing and Installation
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