507581-04
Page 32 of 59
Issue 1933
Figure 47.
Non-Direct Vent Field Supplied Wall
Termination Extended
SIZE TERMINATION
PER EXHAUST PIPE
TERMINATION SIZE
REDUCTION TABLE
* Use wall support every 24” (610 mm). Use two supports of extension is greater than 24”
(610 mm) but less than 48” (1219 mm).
FIELD-PROVIDED
REDUCER MAY BE
REQUIRED TO
ADAPT DIFFERENT
VENT PIPE SIZE TO
TERMINATION
Figure 48.
Non-Direct Vent Application Using Existing
Chimney
STRAIGHT-CUT OR
ANGLE-CUT IN DIRECTION
OF ROOF SLOPE
SHOULDER OF FITTINGS
PROVIDE SUPPORT
OF PIPE ON TOP PLATE
SHEET
METAL TOP
PLATE
Minimum 12” (305MM)
above chimney top
plate or average snow
accumulation
INSULATE
TO FORM
SEAL
EXTERIOR
PORTION OF
CHIMNEY
NOTE:
Do not discharge exhaust gases directly into any
chimney or vent stack. If vertical discharge through an
existing unused chimney or stack is required, insert piping
inside chimney until the pipe open end is above top of
chimney and terminate as illustrated. In any exterior portion
of chimney, the exhaust vent must be insulated.
Exhaust through Crawl Space Vent Option
All 33” condensing gas furnaces (92%+) are now approved
to be vented down through a crawl space. Ensure a vent
pipe drain kit, 51W18 (USA) or 15Z70 (Canada), is used as
directed through the floor joists and into the crawl space.
See the following figures.
Consult the vent tables for vent lengths and approved
materials.
2” or 3”
Sanitary Tee
1/2” PVC
Drain Stub
Drain Trap
Assembly
Rubber Boot (51W18)
Drain Plug (15Z70)
Clamp
(51W18 Only)
From
Furnace
To Vent
Termination
Drain Trap
(assembled)
Figure 49.
Kit 51W18 (USA) / 15Z70 (Canada) Parts
Identification and Assembly
Exhaust from
Furnace
To Termination
Exhaust from
Furnace
To Termination
* Kit 51W18 is shown.
Figure 50. Crawl Space Vent Pipe Drain Trap
Assembled Incorrectly