Lennox International Inc. G24-200 - Manual (Page 16)

Page 16
COMMON VENTING USING TILE−LINED INTERIOR MASONRY CHIMNEY AND COMBINED VENT CONNECTOR
MIN. LENGTH = AS SHORT AS PRACTICAL.
FOR MAX. LENGTH SEE NOTE 1
INTERIOR TILE−LINED
MASONRY CHIMNEY
NOTE − The chimney must be
properly sized per provided vent-
ing tables and lined with a listed
metal lining system.
PERMANENTLY SEALED
FIREPLACE OPENING
G24−200
JOIN HEAT SECTIONS
WITH A ’TEE−Y’
NOTE 1 − Refer to provided venting tables
for installations in the USA and the vent-
ing tables in current CSA−B149.1 for
installations in Canada.
VENT
CONNECTOR
SEE NOTE 2
Note 2 − Either single-walled or double-walled vent
connector may be used. Refer to the capacity re-
quirements as shown in the provided venting tables
for installations in USA and the venting tables in cur-
rent CSA−B149.1 for installations in Canada.
FIGURE 10
General Venting Requirements
All G24−200 furnaces must be vented according to these
instructions.
1 − Vent diameter recommendations and maximum al-
lowable piping runs are found in the provided venting
tables for the USA, and the appropriate venting tables
in the standards of CSA B149.1 of the Natural Gas and
Propane Installation Code for Canada.
2 − In no case should the vent or vent connector diameter
be less than the diameter specified in the provided
venting tables for the USA, and the appropriate vent-
ing tables in the standards of CSA B149.1 of the Natu-
ral Gas and Propane Installation Code for Canada.
3 − Single Appliance Vent − If the vertical vent or tile-lined
chimney has a larger diameter or flow area than the
vent connector, use the vertical vent diameter to de-
termine the minimum vent capacity and the vent
connector diameter to determine the maximum
vent capacity. The flow area of the vertical vent, how-
ever, shall not exceed 7 times the flow area of the
listed appliance categorized vent area, drafthood out-
let area or flue collar area unless designed according
to approved engineering methods.
4 − Multiple Appliance Vents − The flow area of the largest
section of vertical vent or chimney shall not exceed 7
times the smallest listed appliance categorized vent
area, flue collar area or drafthood outlet area unless
designed according to engineering methods.
5 − The entire length of single wall metal vent connector
shall be readily accessible for inspection, cleaning,
and replacement.
6 − Single appliance venting configurations with zero lat-
eral lengths, see tables 3 and 4, are assumed to have
no elbows in the vent system. For all other vent config-
urations, 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) be-
yond two, the maximum capacity listed in the venting
table should be reduced by 10 percent (0.90 x maxi-
mum listed capacity).
7 − The common venting tables 5, 6, 7, and 8 were gener-
ated using a maximum horizontal vent connector
length of 1-1/2 feet (18 inches) for each inch of con-
nector diameter as follows:
TABLE 2
Connector
Diameter
inches (mm)
Maximum Horizontal
Connector Length
feet (m)
3 (76) 4−1/2 (1.37)
4 (102) 6 (1.83)
5 (127) 7−1/2 (2.29)
6 (152) 9 (2.74)
7 (178) 10−1/2 (3.20)
8 − 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 ca-
pacity). The horizontal length of the offset shall not ex-
ceed 1-1/2 feet (.46 m) for each inch (25 mm) of
common vent diameter.
9 − The vent pipe should be as short as possible with
the least number of elbows and angles to do the job.
The vent connector should be routed to the vent using
the shortest possible route.