Installation and Maintenance Manual

Installation: Piping
GTND-SVX01B-EN 35
Air Inlet Collar
Remove screen and mounting plate from air inlet on rear
panel of unit by removing 4 screws. Secure inlet collar and
gasket to inlet opening re-using the 4 screws removed in
step one.
Exhaust Air Collar
Unit sizes 90–120: Secure the reducer fitting (to transition
from 5” pipe to 4” pipe) to the flue collar on the rear panel.
Seal per exhaust venting instructions.
Concentric Vent Terminal—Vertical
Termination
Select location on roof for vent terminal, ensuring
adequate space inside the building/structure for
concentric vent box. Terminal must be at least 6 feet
(1.8 m) from any wall or adjoining building (see Figure 34,
p. 34).
Cut a hole through the roof for combustion air pipe.
Concentric vent box is to be suspended from the
underside of the roof using suitable brackets (field
supplied). Before mounting box, cut a length of pipe so
that dimension A, Figure 34, p. 34, is equal to the
dimension from the top of the box to the roof surface plus
20 inches or plus maximum expected snow depth,
whichever is greater:
• Unit sizes 30–75: Cut a length of 6-inch (152-mm) pipe.
• Unit sizes 90–120: Cu t a lengt h o f 8-inch (203-mm) pipe.
Fasten pipe to combustion air inlet connection of
concentric vent box and seal joint. Insert pipe through roof
and fasten vent box in place. Flash and/or caulk pipe to
roof. Install inlet air screen assembly and fasten to pipe
with screws.
Insert a 5-foot length of Type B vent pipe through the
concentric vent box opening (see Figure 32, p. 33, detail A)
with the “UP” arrow pointing up. Position the pipe to
extend 12 inches beyond the inlet air screen. Secure the
Type B vent pipe in position by drilling three small equally
spaced holes through the collar of the concentric vent box
and inserting sheet metal screws. Install deflector disk on
Type B vent pipe 2-1/2 inches above inlet air screen and
fasten with screws. Seal joint between deflector disk and
pipe with silicone sealant. Install vent terminal on top of
Type B vent pipe, fasten with screws and seal joint.
Connect flue pipe and combustion air pipe from concentric
vent box to unit, following instructions in “Combustion Air
Venting and Piping,” p. 32 and“Exhaust Venting,” p. 32.
Joint between Type B vent pipe and single wall vent pipe
must be sealed with high temperature silicone sealant (see
Figure 33, p. 34). Collars on unit and on concentric vent
box are sized so that crimped ends of combustion air pipes
go toward the unit and crimped ends of flue pipes go away
from the unit.
Concentric Vent Terminal—Horizontal
Termination
Select a location on outside wall for vent terminal. In most
applications, the terminal should be on level with the flue
outlet of the unit less a 1/4 inch per foot pitch for
condensate drainage toward the outside of the building
(see Figure 35, p. 34).
The location of the vent terminal must be in accordance
with the National Fuel Gas Code ANSI Z223.1 in the U.S. or
the Natural Gas Installation Code CAN/CGA-B149.1 or the
Propane Gas Installation Code CAN/CGA-149.2 in Canada.
Refer to Table 6, p. 24 for minimum. In Canada, a vent shall
not terminate above a meter/regulator assembly within
3 feet (0.9 m) horizontally of the vertical centerline of the
regulator nor within 6 feet (1.8 m) of any gas service
regulator vent outlet.
Cut a hole through the wall for a combustion air pipe:
• Unit sizes 30–75: Cut for a 6-inch (152-mm) combustion
air pipe.
• Unit sizes 90–120: Cut for an 8-inch (203-mm)
combustion air pipe.
Figure 36. Unit sizes 30–120: Horizontal intake/vent
installation
WARNING
Risk of Fire and Carbon Monoxide
Poisoning with Improper Piping!
Never use pipe other than diameter stated in Ta b l e 1 ,
p. 12. To prevent pipe from melting and introducing
exhaust fumes into the air supply, never use PVC, ABS
or any other non-metallic pipe for venting! To prevent
fan restriction, an elbow should never be attached
directly to the venter. Failure to follow
recommendations could result in death or serious
injury or equipment damage.
Vent Terminal
(1.8M Min.)
Adjacent Building
D 3330
6'-0" Min.
(0.9M Min.)
3'-0" Min.
Building Overhang