Direct Vent (Dual Pipe ) Piping - Goodman GMV95 Installation Instructions Manual

diameter pipe. To secure the pipe passing through the wall and
prohibit damage to piping connections, a coupling should be in-
stalled on either side of the wall and solvent cemented to a length
of pipe connecting the two couplings. The length of pipe should be
the wall thickness plus the depth of the socket fittings to be in-
stalled on the inside and outside of the wall. The wall penetration
should be sealed with silicone caulking material.
In a basement installation, the vent/flue pipe can be run between
joist spaces. If the vent pipe must go below a joist and then up into
the last joist space to penetrate the header, two 45° elbows should
be used to reach the header rather than two 90° elbows.
Vertical Termination (Single Pipe)
12" MIN.
TO ROOF OR
HIGHEST
ANTICIPATED
SNOW LEVEL
Alternate Vertical Termination (Single Pipe)
WALL
INSIDE
ELBOW OR
COUPLING
Horizontal Termination (Single Pipe)
12" MIN.
Horizontal Termination (Single Pipe)
Above Highest Anticipated Snow Level
D V (D P
IRECT ENT UAL IPE
The inlet air screens provided in the installation instruction packet
are available for the installer to use in the inlet of the combustion
air pipe to prevent animals from building nests in the combustion
air pipe. Installation of screens, while strongly recommended, is
not required and will not affect performance of the unit.
TEE
12 " Min To
Roof Or
Highest Anticipated
Snow Level
90º
MEDIUM RADIUS
ELBOWS
OUTSIDE
TEE
or
90°ELBOW
TURNED
DOWN
COUPLING
MIN.
12"
FROM
12"
WALL TO GROUND OR
HIGHEST ANTICIPATED
SNOW LEVEL
VENT/FLUE TEE
or
90° ELBOW TURNED
DOWN
12" MIN. ABOVE
HIGHEST ANTICIPATED
SNOW LEVEL
) P
IPING
Direct vent installations require both a combustion air intake and a
vent/flue pipe. The pipes may be run horizontally and exit through
the side of the building or run vertically and exit through the roof of
the building. The pipes may be run through an existing unused
chimney; however, they must extend a minimum of 12 inches
above the top of the chimney. The space between the pipes and
the chimney must be closed with a weather tight, corrosion resis-
tant flashing. Both the combustion air intake and a vent/flue pipe
terminations must be in the same atmospheric pressure zone.
Refer to Section IX, Vent/Flue and Combustion Air Pipe - Termina-
tion Locations or Concentric Vent Termination for specific details
on termination construction. For details concerning connection of
pipes to the furnace, refer to the Section IX, Vent/Flue Pipe and
Combustion Pipe - Standard Furnace Connections or Alternate
Furnace Connections.
V /F C
ENT LUE AND OMBUSTION
Refer to the following table for applicable length, elbows, and pipe
diameter for construction of the vent/flue and combustion air intake
pipe systems of a direct vent (dual pipe) installation. The number
of elbows tabulated represents the number of elbows and/or tees
in each (Vent/Flue & Combustion Air Intake) pipe. Elbows and/or
tees used in the terminations must be included when determining
the number of elbows in the piping systems.
If the combustion air intake pipe is to be installed above a finished
ceiling or other area where dripping of condensate will be objec-
tionable, insulation of the combustion air pipe may be required.
Use 1/2" thick closed cell foam insulation such as Armaflex™ or
Insultube™ where required.
Direct Vent (Dual Pipe) Maximum Allowable Length*
of Vent/Flue & Combustion Air Intake Pipe
Unit Input Termination
Pipe
(Btu) Style
(inch)
Standard 2
45,000
Alternate 2
2
Standard
3
70,000
2
Alternate
3
Standard 3
9,000
Alternate 3
Standard 3
115,000
Alternate 3
*Maximum allowable limits listed are individual lengths for inlet & flue and NOT a combination.
COUNTERFLOW
Direct Vent (Dual Pipe) Maximum Allowable Length*
of Vent/Flue & Combustion Air Intake Pipe
Unit Input Termination
Pipe
(Btu) Style
(inch)
2
Standard
3
70,000
2
Alternate
3
2
Standard
3
90,000
2
Alternate
3
*Maximum allowable limits listed are individual lengths for inlet & flue and NOT a combination.
1) Elbows and/or tees used in terminations must be included when deter-
mining quantity of allowable elbows in the system.
2) Number of elbows tabulated are for each (Vent/Flue & Combustion Air
Intake) pipe.
17
A P L
IR IPE ENGTHS AND
UPFLOW
(ft)
(1)(2)(3)(5)
(4) Number of Elbows
1 2 3 4 5
71 68 65 62 59
58 55 52 49 46
49 46 43 40 37
71 68 65 62 59
36 33 30 27 24
57 54 51 48 45
71 68 65 62 59
57 54 51 48 45
49 46 43 40 37
35 32 29 26 23
(ft)
(1)(2)(3)(5)
(4)
Number of Elbows
1 2 3 4 5
49 46 43 40 37
71 68 65 62 59
36 33 30 27 24
57 54 51 48 45
61 58 55 52 49
71 68 65 62 59
48 45 42 39 36
57 54 51 48 45
D
IAMETERS
6 7 8
56 53 50
43 40 37
34 31 28
56 53 50
21 18 15
42 39 36
56 53 50
42 39 36
34 31 28
20 17 14
6 7 8
34 31 28
56 53 50
21 18 15
42 39 36
46 43 40
56 53 50
33 30 27
42 39 36