Whirlpool WGFD293 Installation Instructions Manual page 18

Counterflow
Direct Vent (Dual Pipe) Maximum Allowable Length of Vent/Flue and Combustion Air Intake Pipe—ft (m)
Unit Input Termination
(Btu) Style
70,000 Standard
Alternate
90,000 Standard
Alternate
NOTES:
Maximum allowable limits listed are individual lengths for inlet
and flue and not a combination.
Elbows and/or tees used in the terminations must be
included when determining the number of elbows in the
piping system.
Number of elbows tabulated are for each vent/flue and
combustion air intake pipe.
Minimum length of each vent/flue and combustion air intake
pipe is 5 ft (1.5 m) and one elbow/tee.
2¹⁄₂" (6.4 cm) or 3" (7.6 cm) diameter pipe can be used in
place of 2" (5.1 cm) diameter pipe.
Increased clearance configurations using two 45º long-sweep
elbows should be considered equivalent to one 90º elbow.
Vertical pipe terminations should be as shown in "Vertical
Terminations (Dual Pipe)" illustration. Refer to "Termination
Locations" in this section for details concerning location
restrictions. The penetrations through the roof must be sealed
tight with the proper flashing such as is used with a plastic
plumbing vent.
18
Number of Elbows
Pipe—
in. (cm) 1 2
2 or 2¹⁄₂ 49 (14.9) 46 (14)
(5.12 or 6.4)
3 (7.6) 71 (21.6) 68 (20.7)
2 or 2¹⁄₂ 36 (11) 33 (10.1)
(5.12 or 6.4)
3 (7.6) 57 (17.4) 54 (16.5)
2 or 2¹⁄₂ 61 (18.6) 58 (17.7)
(5.12 or 6.4)
3 (7.6) 71 (21.6) 68 (20.7)
2 or 2¹⁄₂ 48 (14.6) 45 (13.7)
(5.12 or 6.4)
3 (7.6) 57 (17.4) 54 (16.5)
3 4 5
43 (13.1) 40 (12.2) 37 (11.3) 34 (10.4) 31 (9.5) 28 (8.5)
65 (19.8) 62 (18.9) 59 (18)
30 (9.2) 27 (8.2) 24 (7.3) 21(6.4)
51 (15.5) 48 (14.6) 45 (13.7) 42 (12.8) 39 (11.9) 36 (11)
55 (16.8) 52 (15.8) 49 (14.9) 46 (14)
65 (19.8) 62 (18.9) 59 (18)
42 (12.8) 39 (11.9) 36 (11)
51 (15.5) 48 (14.6) 45 (13.7) 42 (12.8) 39 (11.9) 36 (11)
Vertical Vent Terminations (Dual Pipe)
B
A
G
H
B
A
G
H
A. 12" (30.5 cm) minimum
B. Combustion air intake pipe
C. 90º medium radius elbows
D. Tee
E. Vent/flue pipe
6 7 8
56 (17.1) 53 (16.2) 50 (15.2)
18 (5.5) 15 (4.6)
43 (13.1) 40 (12.2)
56 (17.1) 53 (16.2) 50 (15.2)
33 (10.1) 30 (9.2) 27 (8.2)
D
E
C
F
E
C
F
F. 24" (61 cm) maximum, 3" (7.6 cm)
minimum
G. Screen
H. 12" (30.5 cm) minimum to roof or
highest anticipated snow level