30
Do not pitch the vent away from the appliance.
Potential condensate damage to the building
exterior or to the surrounding landscape and/or
potential risks of icing and blockage of the vent
piping could occur.
8. Maintain a minimum clearance per the vent manufac-
ture’s instructions for both combustible or non-com-
bustible materials. The installer must seal any wall,
floor or ceiling penetrations as per local code require-
ments.
9. The vent piping does not require any insulation. The
installer may opt to insulate the vent piping in those
portions of the piping that pass through unheated
spaces such as crawl spaces or attics. In these
areas the installer may apply fiberglass insulation to
the outside of the vent pipe.
WARNING
Table 3 references a long radius 90
º
elbow. For
each additional 90
º
elbow within the system, the
installer must reduce the maximum allowable
length by 7 feet. If a short radius 90
º
elbow is
used the maximum allowable length must be
reduced by 10 feet for each short radius
90
º
elbow. If a 45
º
elbow is used the maximum
allowable length must be reduced by 3 feet for
each 45
º
elbow.
It is recommended that the installer uses the
same number of elbows and length of piping on
the venting system and the combustion air inlet.
BEST PRACTICE
NOTICE
Category III or IV Installation of Vent/Air
MODULATING
DELTA
Model
Feet
Elbows
Feet
Elbows
PG-150
PG-199
PG PLUS-150
PG PLUS-199
Maximum Allowable Vent Piping Length
3 inch Diameter Vent Piping
60
0
46
2
TABLE 3
