Lennox G32V Series Service Literature page 39

Intake Piping
1 − Cement intake piping in slip connector located at top of
unit.
2 − Route piping to outside of structure. Continue with
installation following instructions given in exhaust and
intake piping termination section.
Exhaust Piping
1 − Cement exhaust piping into flue collar socket located
on the left side of the top cap.
2 − All horizontal runs of exhaust pipe must slope back to-
ward unit. A minimum of 1/4" (6mm) drop for each 12"
(305mm) of horizontal run is mandatory for drainage.
Horizontal runs of exhaust piping must be supported ev-
ery 5 ft. (1.52m) using hangers for schedule 40 pipe. All
other pipe must be supported every 3 ft. (.91m).
NOTE − Exhaust piping should be checked carefully to
make sure there are no sags or low spots.
NOTE − Exhaust piping must be insulated with 1/2"
(13mm) Armaflex or equivalent when run through un-
heated space. Do not leave any area of exhaust pipe
open to outside air; exterior exhaust must be insulated
with 1/2" (13mm) Armaflex or equivalent.
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 beyond the top or outlet end of the
metal stack.
CAUTION
The exhaust vent pipe operates under positive
pressure and must be completely sealed to pre-
vent leakage of combustion products into the liv-
ing space.
Removal of Unit from Common Venting System
In the event that an existing furnace is removed from a vent-
ing system commonly run with separate gas appliances,
the venting system may be too large to properly vent the re-
maining attached appliances. The following test should be
conducted while all appliances (both in operation and those
not in operation) are connected to the common venting sys-
tem. If the venting system has been installed improperly,
corrections must be made as outlined in the previous sec-
tion.
1 − Seal any unused openings in the common venting sys-
tem.
2 − Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage or
restriction, leakage, corrosion and other deficiencies
which could cause an unsafe condition.
3 − Insofar as is practical, close all building doors and win-
dows and all doors between the space in which the ap-
pliances remaining connected to the common venting
system are located and other spaces of the building. Turn
on clothes dryers and any appliances not connected to
the common venting system. Turn on any exhaust fans,
such as range hoods and bathroom exhausts, so they will
operate at maximum speed. Do not operate a summer
exhaust fan. Close fireplace dampers.
4 − Follow the lighting instruction. Place the appliance be-
ing inspected in operation. Adjust thermostat so ap-
pliance will operate continuously.
5 − Test for spillage at the draft hood relief opening after 5
minutes of main burner operation. Use a draft gauge or
the flame of match or candle, or smoke from a cigarette,
cigar.
6 − After it has been determined that each appliance re-
maining connected to the common venting system
properly vents when tested as outlined above, return
doors, windows, exhaust fans, fireplace dampers and
any other gas-burning appliance to their previous con-
dition of use.
7 − If improper venting is observed during any of the above
tests, the common venting system must be corrected.
The common venting system should be re−sized to ap-
proach the minimum size as determined by using the
appropriate tables in appendix G in the current stan-
dards of the National Fuel Gas Code ANSI Z223−1 in
the U.S.A., and the appropriate Category 1 Natural
Gas and Propane appliances venting sizing tables in
the current standards of the CAN/CGA−B149.1 and .2
in the Natural Gas and Propane Installation Code in
Canada.
Intake and Exhaust Piping Terminations
Intake and exhaust pipes may be routed either horizontally
through an outside wall or vertically through the roof. In attic
or closet installations, vertical termination through the roof
is preferred. Figures 34 through 46 show typical termina-
tions.
1 − Use recommended piping materials for both intake
and exhaust piping.
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