Lennox EL296UHV Series Unit Information page 69

Maximum Allowable Exhaust Vent Pipe Length (in ft.
Winter Design Temperatures Two - Stage High Efficiency Furnace
Winter Design
Temperatures1 °F
(°C)
32 to 21
(0 to -6)
20 to 1
(-7 to -17)
0 to -20
(-18 to -29)
1Refer to 99% Minimum Design Temperature table provided in the current edition of the ASHRAE Fundamentals Handbook.
2 Poly-Propylene vent pipe (PP) by Duravent and Centrotherm.
3 Vent length in table is equivalent length. Consider each elbow as 5ft. of linear length
NOTE - Concentric terminations are the equivalent of 5' and should be considered when measuring pipe length.
NOTE - Maximum unisulated vent lengths listed may include the termination(vent pipe exterior to the structure) and cannot exceed 5 linear feet or
the maximum allowable intake or exhaust vent length listed in table 24 or 25 which ever is less.
NOTE - If insulation is required in an unconditioned space, it must be located on the pipe closest to the furnace. See FIGURE 29.
Vent Pipe
Diameter 045
PP
PVC
2
1-1/2 22 n/a
2 in 21 18
2-1/2 in 16 n/a
3 in 12 12
1-1/2 12 n/a
2 in 11
2-1/2 in 7 n/a
3 in 2
1-1/2 8 n/a
2 in 6
2-1/2 in 1 n/a
3 in 1
Conditioned
Space
TABLE 26
) Without Insulation In Unconditioned Space For
3
Unit Input Size
070
PP
PVC PVC
2
25 n/a n/a
33 30 46
26 n/a 37
21 21 30
20 n/a n/a
9 19 17 28
14 n/a 21
2 9 9 16
13 n/a n/a
4 12 10 19
7 n/a 13
1 2 2
Conditioned
Space
Pipe Insulation
Unconditioned
Space
FIGURE 29
Page 69
090 110
PP PP
PVC
2 2
n/a n/a n/a
42 30 30
n/a 36 n/a
30 29 29
n/a n/a n/a
25 27 24
n/a 20 n/a
16 14 14
n/a n/a n/a
16 18 15
n/a 12 n/a
8 8 7 7
Exhaust
Pipe
Intake
Pipe
135
PP
PVC
2
n/a n/a
n/a n/a
n/a n/a
42 42
n/a n/a
n/a n/a
n/a n/a
23 23
n/a n/a
n/a n/a
n/a n/a
13 13