Page 43
After reassemble, double check all connections to
prevent exhaust products from entering living
space.
WARNING
S − Concentric Termination
(Figures 55, 56 and 57 )
In concentric termination, intake and exhaust piping are
centrally located. See figures 55 and 56. See figure 57 for
a detailed cutaway.
CONCENTRIC ROOFTOP TERMINATION
EXHAUST
TERMINATION
INTAKE
TERMINATION
EXHAUST
INTAKE
12" ABOVE AVERAGE SNOW
ACCUMULATION
FIGURE 55
CONCENTRIC WALL TERMINATION
EXHAUST
INTAKE
EXHAUST
TERMINATION
INTAKE
TERMINATION
FIGURE 56
CONCENTRIC WALL TERMINATION
(CUTAWAY)
EXHAUST
INTAKE
EXHAUST
TERMINATION
INTAKE TERMINATION
EXHAUST TUBE
INTAKE TUBE
TOP VIEW
SIDE VIEW
FIGURE 57
Exhaust piping must terminate straight out or up at a level 12
inches above normal snow accumulation. Termination must
not be within six feet of other vents or three feet of structure
openings. For proper vent sizes see table 14 .
MINIMUM DIAMETER FOR G21/GSR21 VENTING
Number of 90
°
Elbows
Pipe Length
(Max. Feet)
0
2
4
6
8
5
10
20
30
40
50
60
70
80
90
2
2
2
2
2
2−1/2
2−1/2
2−1/2
2−1/2
2−1/2
2−1/2
2−1/2
2−1/2
3
2
2
2
2
2
2−1/2
2−1/2
2−1/2
2−1/2
3
2
2
2
2
3
2−1/2
2−1/2
2−1/2
2−1/2
3
2
2
2
3
3
2−1/2
2−1/2
2−1/2
2−1/2
3
2
2
3
3
3
2
TABLE 14
Refer to GSR21/GSR14 Exhaust/Intake Air Termination
Kits installation instructions for installation procedures
which meet local and national codes.
IMPORTANT
The exhaust line must be reduced at wall termina
tion to 11/2".
T − Standard Intake/Exhaust Termination
(Figures 58, 59, 60, 61 )
Intake and exhaust pipes should be placed as close to
gether as possible at termination end. MAXIMUM SEP
ARATION IS 3 IN. ON ROOF TERMINATION AND 6 IN.
ON SIDE WALL TERMINATIONS. END OF EXHAUST
PIPE MUST EXTEND AT LEAST 8 IN. PAST END OF IN
TAKE PIPE.
Intake MUST be upwind (prevailing wind) of exhaust pipe.
Both intake and exhaust MUST be in the same pressure
zone (do not exit one through the roof and one through the
side of the house). These precautions are to ensure that no
exhaust gas recirculation occurs.
Exhaust piping must terminate straight out or up and ter
mination must not be within six feet of other vents or three
feet of structure openings. For proper sizing see table 14.
Refer to G21/GSR21 operation and installation instruc
tions for detailed instruction of proper termination installa
tions which meet local and national codes.
