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, piping 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.
See figure 37.
2" EXTENSION FOR 2" PVC
PIPE1" EXTENSION FOR 3"
PVC PIPE
4''
FURNACE
INTAKE
PIPE
FLUSH-MOUNT SIDE WALL TERMINATION KIT
51W11 (US) or 51W12 (Canada)
FIGURE 34
12" (305mm)
Minimum
Above Average
Snow
Accumulation
CLAMP
DIRECT VENT CONCENTRIC ROOFTOP TERMINATION
71M80, 69M29 or 60L46 (US)
44W92 or 44W93 (Canada)
FIGURE 35
FURNACE
EXHAUST
PIPE
GLUE EXHAUST
END FLUSH INTO
TERMINATION
FLAT
1-1/2" ACCELERATOR
SIDE
FLASHING
INTAKE
(Not Furnished)
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
FIELD-PROVIDED
QUIRED TO ADAPT
LARGER VENT PIPE
SIZE TO TERMINATION.
EXHAUST
AIR
INTAKE
AIR
(Not Furnished)
DIRECT VENT CONCENTRIC WALL TERMINATION
71M80, 69M29 or 60L46 (US)
41W92 or 41W93 (Canada)
EXHAUST
VENT
INTAKE
AIR
Inches (mm)
optional intake elbow
OPTIONAL VENT TERMINATION FOR MULTIPLE UNIT
INSTALLATION OF DIRECT VENT 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
OUTSIDE
INTAKE
WALL
AIR
12" (305mm) Min.
INTAKE
CLAMP
above grade or
AIR
GRADE
FIGURE 36
12"
(305mm)
5-1/2"
5"
(140mm)
(127mm)
18" MAX.
Front View
(457mm)
EXHAUST VENT
12" (305mm) Min.
above grade or
INTAKE
cumulation.
AIR
Side View
(30G28 or 81J20)
FIGURE 37
STRAIGHT-CUT OR
ANGLE-CUT IN DIRECTION
OF ROOF SLOPE *
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
EXHAUST
AIR
cumulation.
ALTERNATE
INTAKE PIPE
EXTERIOR
PORTION OF
CHIMNEY