INSTALLATION CONSIDERATIONS
17
The following bullets and diagram describe the restrictions
concerning the appropriate location of vent/flue pipe and
combustion air intake pipe (when applicable) terminations.
Refer to the installation instructions for specific details on
termination construction.
•
All terminations must be located at least 12 inches above
ground level or the anticipated snow level.
•
Vent terminations must terminate at least 3 feet above
any forced air inlet located within 10 feet.
NOTE:
This provision does not apply to the combustion
air intake termination of a direct vent application.
•
The vent termination of a
non-direct
vent
application
must terminate at least 4 feet below, 4 feet horizontally
from, or 1 foot above any door, window, or gravity air
inlet into any building.
•
The vent termination of a
direct vent
application must
terminate at least 12 inches from any opening through
which flue gases may enter a building (door, window,
or gravity air inlet).
•
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 anticipated
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 precedence
over the preceding termination restrictions.
Direct Vent Installations
On
upflow
units secure the combustion air intake pipe directly
to the air intake coupling. On
counterflow
units secure the
combustion air intake pipe to the air intake coupling using the
rubber coupling and worm gear hose clamps provided with the
unit. The counterflow rubber coupling allows service removal
of air intake piping internal to the furnace blower compartment.
The combustion air intake pipe can also be secured directly
to the counterflow unit air intake pipe coupling.
Non-Direct Vent Installations
A minimum of one 90° elbow must be installed on the combustion
air intake “coupling” to guard against inadvertent blockage.
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.
CAUTION
B
E SURE NOT TO DAMAGE INTERNAL WIRING OR OTHER COMPONENTS WHEN
REINSTALLING COUPLING AND SCREWS.
Vent/Flue Pipe Lengths and Diameters
Refer to the following tables for applicable length, elbows, and
pipe diameter for construction of the vent/flue pipe system of a
non-direct vent installation. In addition to the vent/flue pipe, a
single 90° elbow must be secured to the combustion 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 system.
DM92SE* Direct Vent (2-Pipe)
and
Non-Direct Vent (1-Pipe) (6)
Maximum Allowable Length of Vent/Flue Pipe
and
Combustion Air Pipe (Ft) (1) (2)
ELBOWS
MODEL
PIPE
SIZE
1 2 3 4 5 6 7 8
DM92SE0402BN
2
165
160 155 150 154 140 135 130
3
168
161 154 147 140 133 126 119
DM92SE0603BN
2
55 50 45 40 35 30 25 20
3
127 120 113 106 99 92 85 78
DM92SE0803BN
2^
30 25 20 15 10 5
N/A N/A
3^
72 65 58 51 44 37 30 23
DM92SE0804CN
2^
30 25 20 15 10 5
N/A N/A
3^
72 65 58 51 44 37 30 23
DM92SE0805CN
2^
40 35 30 25 20 15 8 1
3
72 67 62 57 52 47 40 33
DM92SE1004CN
2
60 55 50 45 40 35 28 21
3
168 163 158 153 148 143 136 129
DM92SE1005CN
2
30 25 20 15 10 5
N/A N/A
3
113 106 99 92 85 78 71 64
DM92SE1205DN
2
N/A
N/A N/A N/A N/A N/A N/A N/A
3
65 58 51 44 37 30 23 16
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 considered equivalent to one 90 deg. elbow.
6) One 90° elbow should be secured to the combustion air intake connection.
Vent/Flue and Combustion Air Pipe Lengths and Diameters
Refer to the preceding table for applicable length, elbows, and
pipe diameter for construction of the vent/flue and combus
-
tion air intake pipe systems of a non-direct vent (single pipe)
installation. The number of elbows tabulated represents the
number of elbows and/or tees in each (Vent/Flue & Combustion