INSTALLATION CONSIDERATIONS
18
•
The vent termination of vent pipe run vertically through
a roof must terminate at least 12 inches above the
roof line (or the anticipated snow level) and be at least
12 inches from any vertical wall (including any antici-
pated snow build up).
•
A vent termination shall not terminate over public walk-
ways or over an area where condensate or vapor could
create a nuisance or hazard or could be detrimental
to the operation of regulators, relief valves, or other
equipment.
•
The combustion air intake termination of a direct vent
application should not terminate in an area which is
frequently dusty or dirty.
NOTE:
In Canada, the B149 Fuel Gas Code takes prece-
dence over the preceding termination restrictions.
12"
12"
NON-DIRECT VENT
VENT/FLUE TERMINATION
NO TERMINATIONS
ABOVE WALKWAY
12"
4'
4'
NON-DIRECT VENT
VENT/FLUE TERMINATION
DIRECT VENT
VENT/FLUE TERMINATION
12"
10'
3"
FORCED AIR
INLET
OTHER THAN
COMBUSTION AIR
TERMINATION INTAKE
GRADE OR HIGHEST
ANTICIPATED
SNOW LEVEL
90% Furnace Vent Termination Clearances
WARNING
T
HE RUBBER ELBOW IS NOT DESIGNED TO SUPPORAT A LOAD.
W
HEN THE
RUBBER ELBOW IS MOUNTED EXTERNALLY TO THE FURNACE CABINET,
EXTREME CARE MUST BE TAKEN TO ADEQUATELY SUPPORT FIELD-SUPPLIED
VENT/FLUE PIPING, AS DAMAGE CAN RESULT IN LEAKS CAUSING BODILY
INJURY OR DEATH DUE TO EXPOSURE TO FLUE GASES, INCLUDING CARBON
MONOXIDE.
Vent/Flue Pipe Lengths (Non-Direct Vent) and Diam-
eters
Refer to the following tables for applicable length, elbows,
and pipe diameter for construction of the vent/flue pipe sys-
tem of a non-direct vent installation. In addition to the vent/
flue pipe, a single 90° elbow must be secured to the com-
bustion air intake to prevent inadvertent blockage. The tee
or elbows used in the vent/flue termination must be included
when determining the number of elbows in the piping sys-
tem.
1
2
3
4
5
6
7
8
40,000
2
or 2 1/2
120
115
110
105
100
95
90
85
60,000
2
or 2 1/2
95
90
85
80
75
70
65
60
80,000 "B"
2 or 2 1/2
75
70
65
60
55
50
45
40
80,000 "B"
3
200
193
186
179
172
165
158
151
80,000 "C"
2 or 2 1/2
25
20
15
10
5
N/A
N/A
N/A
80,000 "C"
3
200
193
186
179
172
165
158
151
100,000
2 or 2 1/2
25
20
15
10
5
N/A
N/A
N/A
100,000
3
200
193
186
179
172
165
158
151
120,000
2 or 2 1/2
45
40
35
30
25
20
15
10
120,000
3
95
90
85
80
75
70
65
60
*MEC96 Direct Vent (2 - Pipe) and Non-Direct Vent (1- Pipe)
(6)
M aximum Allowable Length of Vent/Flue Pipe
& Combustion Air Pipe (ft)
(1) (2)
Unit Input
(Btu)
Pipe Size
(4)
(in.)
Number of Elbows
(3) (5)
1)
Maximum allowable limits listed on individual lengths for inlet and flue and NOT a combination.
2)
Minimum requirement for each vent pipe is five (5) feet in length and one elbow/tee.
3)
Tee used in the vent/flue termination must be included when determining the number of elbows in
the piping system.
4)
2 1/2” or 3” diameter pipe can be used in place of 2” diameter pipe.
5)
Increased Clearance Configurations using (2) 45 deg. Long Sweep elbows should be consid-
ered equivalent to one 90 deg. elbow.
6)
One 90° elbow should be secured to the combustion air intake connection.
12" MINIMUM
VENT/FLUE TEE
OR
90° ELBOW TURNED
DOWN
12" MINIMUM ABOVE
HIGHEST ANTICIPATED
SNOW LEVEL
90% Furnace Horizontal Termination (Single Pipe)
Above Highest Anticipated Snow Level
