Lennox MERIT Series Installation Instructions Manual page 27

7 - If intake and exhaust piping must be run up a side
wall to position above snow accumulation or other
obstructions, iping must be supported. At least one
bracket must be used within 6" from the top of the
elbow and then every 24" (610mm) as shown in
Figure 39, to prevent any movement in any direction.
When exhaust and intake piping must be run up an
outside wall, the exhaust piping must be terminated
with pipe sized per table 10.The intake piping may
be equipped with a 90° elbow turndown. Using
turndown will add 5 feet (1.5m) to the equivalent
length of the pipe.
8 - A multiple furnace installation may use a group of up
to four terminations assembled together horizontally,
as shown in Figure 36.
12" (305mm)
Minimum
Above Average
Snow
Accumulation
CLAMP
DIRECT VENT CONCENTRIC ROOFTOP TERMINATION
71M80, 69M29 or 60L46 (US)
44W92 or 44W93 (Canada)
Figure 34
FIELD-PROVIDED
REDUCER MAY BE
REQUIRED TO ADAPT
LARGER VENT PIPE
OUTSIDE
SIZE TO TERMINATION
WALL
EXHAUST
AIR
INTAKE
CLAMP
AIR
(Not Furnished)
DIRECT VENT CONCENTRIC WALL TERMINATION
71M80, 69M29 or 60L46 (US)
44W92 or 44W93 (Canada)
Figure 35
Accelerator not required for
3" concentric
FLASHING
(Not Furnished)
INTAKE
SHEET METAL STRAP
(Clamp and sheet metal strap
must be field installed to support
the weight of the termination kit.)
FIELD-PROVIDED
REDUCER MAY BE REQUIRED
TO ADAPT LARGER VENT
PIPE SIZE TO TERMINATION
Accelerator not required
for 3" concentric
INTAKE
AIR
EXHAUST
AIR
INTAKE 12" (305mm) Min.
AIR
above grade or
average snow ac
cumulation.
GRADE
EXHAUST
VENT
INTAKE
AIR
Inches (mm)
optional intake elbow
OPTIONAL VENT TERMINATION FOR MULTIPLE UNIT
INSTALLATION OF DIRECT VENT WALL TERMINATION KIT
2" EXTENSION FOR 2" PVC
PIPE1" EXTENSION FOR 3"
PVC PIPE
FURNACE
INTAKE
PIPE
FLUSH-MOUNT SIDE WALL TERMINATION KIT
DIRECT VENT APPLICATION
USING EXISTING CHIMNEY
Minimum 12" (305MM)
above chimney top
plate or average snow
accumulation
NOTE - Do
tical discharge through an existing unused chimney or stack is required, insert piping
inside
trated. In any exterior portion of chimney, the exhaust vent must be insulated.
Page 27
(305mm)
5-1/2"
5"
(140mm)
(127mm)
18" MAX.
(457mm)
EXHAUST VENT
12" (305mm) Min.
above grade or
INTAKE
AIR
Side View
(30G28 or 81J20)
Figure 36
FURNACE
EXHAUST
4''
PIPE
GLUE EXHAUST
END FLUSH INTO
TERMINATION
FLAT
1-1/2" ACCELERATOR
SIDE
51W11 (US) or 51W12 (Canada)
Figure 37
ANGLE-CUT IN DIRECTION
3" - 8"
(76mm-
8" - 12"
203mm)
(203mm - 305mm)
SHOULDER OF FITTINGS
INTAKE PIPE
PROVIDE SUPPORT
INSULATION (optional)
OF PIPE ON TOP PLATE
SHEET
METAL TOP
PLATE
3" - 8"
(76mm-
203mm)
INSULATE
TO FORM
SEAL
Figure 38
12"
Front View
cumulation.
STRAIGHT-CUT OR
OF ROOF SLOPE *
ALTERNATE
INTAKE PIPE
EXTERIOR
PORTION OF
CHIMNEY