Lennox Merit Series Installation Instructions Manual page 11

Common Venting Using Tile−Lined Interior Masonry Chimney and Combined Vent Connector
NOTE− Refer to provided venting
tables for installations.
6 − The entire length of single wall metal vent connector
shall be readily accessible for inspection, cleaning,
and replacement.
7 − Single appliance venting con gurations with zero lateral
lengths are assumed to have no elbows in the vent
system. For all other vent con gurations, the vent
system is assumed to have two 90° elbows. For each
additional 90° elbow or equivalent (for example two
45° elbows equal one 90° elbow) beyond two, the
maximum capacity listed in the venting table should
be reduced by 10% (0.90 x maximum listed capacity).
8 − The common venting tables (5, 6, 7, and 8) were gen-
erated using a maximum horizontal vent connector
length of 1−1/2 feet (.46 m) for each inch (25 mm) of
connector diameter as follows:
Connector Diameter
inches (mm)
3 (76)
4 (102)
5 (127)
6 (152)
7 (178)
9 − If the common vertical vent is offset, the maximum
common vent capacity listed in the common venting
tables should be reduced by 20%, the equivalent of two
90° elbows (0.80 x maximum common vent capacity).
The horizontal length of the offset shall not exceed
MINIMUM LENGTH = AS SHORT AS PRACTICAL.
FOR MAXIMUM LENGTH SEE NOTE TO LEFT
OTHER
APPLIANCE
FIGURE 12
Maximum Horizontal
Connector Length feet (m)
4−1/2 (1.37)
6 (1.83)
7−1/2 (2.29)
9 (2.74)
10−1/2 (3.20)
VENTING
VENT
CONNECTOR
FURNACE
1-1/2 feet (.46 m) for each inch (25 mm) of common
vent diameter.
10 − The vent pipe should be as short as possible with the
least number of elbows and angles required to com-
plete the job. Route the vent connector to the vent us-
ing the shortest possible route.
11 − A vent connector shall be supported without any dips
or sags and shall slope a minimum of 1/4 inch (6.4 mm)
per linear foot (305 mm) of connector, back toward the
appliance.
12 − Vent connectors shall be rmly attached to the furnace
ue collar by self−drilling screws or other approved
means, except vent connectors of listed type B vent
material which shall be assembled according to the
manufacturer's instructions. Joints between sections
of single wall connector piping shall be fastened by
screws or other approved means.
13 − When the vent connector used for Category I ap-
pliances must be located in or pass through a crawl-
space, attic or other areas which may be cold, that por-
tion of the vent connector shall be constructed of listed
double-wall type B vent material or material having
equivalent insulation qualities.
14 − All venting pipe passing through oors, walls, and ceil-
ings must be installed with the listed clearance to com-
bustible materials and be re stopped according to lo-
cal codes. In absence of local codes, refer to NFGC
(Z223.1).
15 − No portion of the venting system can extend into, or pass
through any circulation air duct or plenum.
INTERIOR TILE−LINED
MASONRY CHIMNEY
NOTE − the chimney must be properly
sized per provided venting tables or
lined with listed metal lining system.
PERMANENTLY
SEALED FIREPLACE
OPENING
11