Lennox G61MPV Series

NOTE - The flue collar on all models is sized to accommo-
date 2" Schedule 40 flue pipe. When vent pipe which is
larger than 2" must be used in an upflow appfication, a 2"
elbow must be applied at the flue collar in order to properly
transition to the larger diameter flue pipe. This elbow must
be added to the elbow count used to determine acceptable
vent lengths. Assign an equivalent feet value to this elbow
according to the larger size pipe being used. Contact the
Appfication Department for more information concerning
sizing of vent systems which include multiple pipe sizes.
Use the following steps to correctly size vent pipe diameter.
Refer to Vent Pipe Size Determination Worksheet on
page 65.
1 - Determine the vent termination and its corresponding
equivalent feet value according to table 5,
2 - Determine the number of 90° elbows required for both
indoor and outdoor (e,g. snow riser) use. Calculate the
corresponding equivalent feet of vent pipe,
3 - Determine the number of 45° elbows required for both
indoor and outdoor use, Calculate the corresponding
equivalent feet of vent pipe.
4 - Determine the length of straight pipe required,
5- Add the total equivalent feet calculated in steps 1
through 4 and compare that length to the maximum
values given in table 7 for the proposed vent pipe di-
ameter. If the total equivalent length required exceeds
the maximum equivalent length listed in the appropri-
ate table, evaluate the next larger size pipe.
A, IMPORTANT
TABLE 6
MINIMUM VENT PIPE LENGTHS
G61MPV
MODEL
045,070,
071,090,
091
110,
111"*
135"**
MIN. EQUIV.
VENT LENGTH
15 ft.*
EXAMPLE
5 ft. plus 2 elbows of 2", 2-1/2", 3"
or 4" diameter pipe
5 ft. plus 2 elbows of 2-1/2" 3" or 4"
diameter pipe
5 ft, plus 2 elbows of 3" or 4"
diameter pipe
*Any approved termination may be added to the minimum equivalent
length listed.
**G61MPV-60C-110 and -111 must have 90° street ell (suppfied) installed
directly into unit flue collar.
***G61MPV-60D-135 must have 3" to 2" reducing eli (supplied) installed
directly into unit flue collar.
TABLE 7
MAXIMUM VENT PIPE LENGTHS
MAXIMUM EQUIVALENT VENT
G61MPV LENGTH FEET
ALTITUDE
MODEL 2" 2-1/2" 3" 4"
PIPE PIPE PiPE PiPE
045 59 65 77 234
070 59 65 78 214
0711- 59 65 78 214
0 - 4500 090 26 42 72 204
(0 - 1371 m) 0911- 26 42 72 204
110" n/a 32 72 179
111"1- n/a 32 72 179
135"*:1: n/a n/a 61 160
045 59 65 77 234
070 59 65 78 214
0711- 59 65 78 214
4501-7500 090 26 42 72 204
(1372-2286 m) 0911- 26 42 72 204
110" n/a 32 72 179
111"1- n/a 32 72 179
135"*:I: n/a n/a 46 160
045 59 65 77 234
070 59 65 78 214
0711- 59 65 78 214
7501 - 10000 090 26 42 72 204
(2287 - 3048 m) 0911- 26 42 72 204
110" n/a 32 72 179
111"1- n/a 32 72 179
135"*:1: n/a n/a 46 160
n/a -- Not allowed.
*G61MPV-60C-110 and -111 must have 90° street eli (supplied) installed
directly into unit flue collar.
**G61MPV-60D-135 must have 3" to 2" reducing eli (supplied) installed
directly into unit flue collar.
_On G61MPV-071, -091 and -111 units, sweep elbows must be used
for afl 90 ° elbows in the venting system when 2", 2-1/2" or 3" vent
pipe is used. Sweep elbows are recommended for use in vent sys-
tems of other G61MPV units.
_On G61MPV-60D-135 units, sweep elbows must be used for all 90 ° el-
bows in the vent system when 3" vent pipe is used.
All cementing of joints should be done according to the
specifications outlined in ASTM D 2855.
A, WARNING
1 - Measure and cut vent pipe to desired length,
2 - Debur and chamfer end of pipe, removing any ridges
or rough edges, If end is not chamfered, edge of pipe
may remove cement from fitting socket and result in a
leaking joint,
3 - Clean and dry surfaces to be joined.
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