17
12 " Min To
Roof Or
Highest Anticipated
Snow Level
TEE
Vertical Termination (Single Pipe)
12" MIN.
TO ROOF OR
HIGHEST
ANTICIPATED
SNOW LEVEL
90º
MEDIUM RADIUS
ELBOWS
Alternate Vertical Termination (Single Pipe)
MIN.
12"
FROM
WALL
12"
TO GROUND OR
HIGHEST ANTICIPATED
SNOW LEVEL
WALL
INSIDE
OUTSIDE
TEE
or
90°ELBOW
TURNED
DOWN
COUPLING
ELBOW OR
COUPLING
Horizontal Termination (Single Pipe)
VENT/FLUE TEE
or
90° ELBOW TUR NED
DOWN
12" MIN.
Horizontal Termination (Single Pipe)
Above Highest Anticipated Snow Level
D
IRECT
V
ENT
(D
UAL
P
IPE
) P
IPING
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.
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.
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
ENT
/F
LUE
AND
C
OMBUSTION
A
IR
P
IPE
L
ENGTHS
AND
D
IAMETERS
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.
Pipe
Siz e
(4)
(in.)
2
3
4
5
6
7
8
Standard
2
68
65
62
59
56
53
50
A lternate
2
55
52
49
46
43
40
37
Standard
2
68
65
62
59
56
53
50
A lternate
2
55
52
49
46
43
40
37
Standard
2
46
43
40
A lternate
2
33
30
27
Standard
3
68
65
62
59
56
53
50
A lternate
3
55
52
49
46
43
40
37
Standard
3
68
65
62
59
56
53
50
A lternate
3
55
52
49
46
43
40
37
Standard
3
68
65
62
59
56
53
50
A lternate
3
55
52
49
46
43
40
37
Not Rec ommended
115_5
Dire ct Ve n t (Dual Pipe )
Max imum A llow able Length of V ent/Flue & Combus tion
Air Intake Pipe (f t)
Unit Input
(Btu)
Number of Elbow s
(1)(2)(3)(5)
090_4
V ent/Flue/Air Intake
Termination
045_3
070_3
070_4
090_5
1) Minimum requirement for each vent pipe is five (5) feet in length and one
elbow/tee.
2) Tees and/or elbows used in the vent/flue termination must be included
when determining the number of elbows in the piping system.
3) 3” diameter pipe can be used in place of 2” diameter pipe.
4) Increased Clearance Configurations using (2) 45 deg. Long Sweep
elbows should be considered equivalent to one 90 deg. elbow.
V
ENT
/F
LUE
AND
C
OMBUSTION
A
IR
P
IPE
T
ERMINATIONS
The vent/flue and combustion air pipes may terminate vertically, as
through a roof, or horizontally, as through an outside wall.
Vertical pipe terminations should be as shown in the following
figure.
Refer to Section IX, Vent/Flue Pipe and Combustion Pipe -
Termination Locations
for details concerning location restrictions.
The penetrations through the roof must be sealed tight with proper
flashing such as is used with a plastic plumbing vent.
TEE
12" MIN.
12" MIN.
TO ROOF OR
HIGHEST
ANTICIPATED
SNOW LEVEL
VENT/FLUE
90º
MEDIUM RADIUS
ELBOWS
COMBUSTION
AIR INTAKE
24" MAX.
3" MIN.
SCREEN
Vertical Terminations (Dual Pipe)
Summary of Contents for GMS95
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