Venting Pracitces - Lennox SIGNATURE SLP99DFV Installation Instructions Manual

Venting Pracitces

Piping Suspension Guidelines
SCHEDULE 40
PVC - 5'
all other pipe* - 3'
* See Piping and Fittings Specifications table
NOTE - Isolate piping at the point where it exits the outside wall or
roof in order to prevent transmission of vibration to the structure.
Wall Thickness Guidelines
24" maximum
3/4" minimum
n i s d i e
FIGURE 18
REPLACING FURNACE THAT WAS PART OF A
COMMON VENT SYSTEM
CHIMNEY
OR GAS
VENT
(Check sizing
for water
heater only)
FURNACE
(Replaced)
If replacing a furnace which was
commonly vented with another gas appliance, the size
of the existing vent pipe for that gas appliance must be
checked. Without the heat of the original furnace flue
products, the existing vent pipe is probably oversized for
the single water heater or other appliance. The vent
should be checked for proper draw with the remaining
appliance.
FIGURE 19
Wall
o u s t d i e
WATER
HEATER
OPENINGS
(To Adjacent
Room)
Page 15
1 - n areas where piping penetrates joists or interior
walls, hole must be large enough to allow clearance
on all sides of pipe through center of hole using a
hanger.
2 - When furnace is installed in a residence where unit
is shut down for an extended period of time, such
as a vacation home, make provisions for draining
condensate collection trap and lines.
Exhaust Piping (FIGURE 21, FIGURE 22 and FIGURE
23)
Route piping to outside of structure. Continue with instal-
lation following instructions given in piping termination
section.
WARNING
Carbon Monoxide Poisoning Hazard
Cutting or altering exhaust or air intake pipes, which
are located in the blower compartment, could result
in Carbon Monoxide Poisoning or Death.
CAUTION
Do not discharge exhaust into an existing stack
or stack that also serves another gas appliance. If
vertical discharge through an existing unused stack
is required, insert PVC pipe inside the stack until the
end is even with the top or outlet end of the metal
stack.
CAUTION
The exhaust vent pipe operates under positive
pressure and must be completely sealed to prevent
leakage of combustion products into the living
space.
Vent piping Guidliens
NOTE - Lennox has approved the use of DuraVent® and
Centrotherm manufactured vent pipe and terminations
as an option to PVC. When using the PolyPro® by Du-
raVent or InnoFlue® by Centrotherm venting system the
vent pipe requirements stated in the unit installation in-
struction – minimum & maximum vent lengths, termination
clearances, etc. – apply and must be followed. Follow the
instructions provided with PoyPro by DuraVent and Inno-
Flue® by Centrotherm venting system for assembly or if
requirements are more restrictive. The PolyPro by Du-
ravent and InnoFlue by Centrotherm venting system must
also follow the uninsulated and unconditioned space crite-
ria listed in TABLE 10.
The SLP99DFV is installed only as a Direct Vent gas
central furnace.
NOTE - In Direct Vent installations, combustion air is taken
from outdoors and flue gases are discharged outdoors. In-
take and exhaust pipe sizing -- Size pipe according to TA-
BLE 7 and TABLE 8. Count all elbows inside and outside
the home. TABLE 7 lists the minimum vent pipe lengths
permitted. TABLE 8 lists the maximum pipe lengths per-
mitted.