Maximum Length of Sidewall Vent Pipe
The maximum installed length of the flue from
the appliance to the point of termination,
outside of the building, must
not exceed a maximum of 50 equivalent feet
(15.2m) in length. Subtract 5 feet (1.5m)
of equivalent length for each 90° elbow
and 2-1/2 feet (0.7m) of equivalent length for
each 45° elbow installed in the vent.
Location of a Sidewall Vent Termination
The vent cap shall terminate at least 3 feet
(0.91m) above any forced air inlet within 10
feet (3.05m). The vent shall terminate at least
4 feet (1.22m) below, 4 feet (1.22m)
horizontally from, or 1 foot (0.30m) above
and 2 feet (0.60m) horizontally from any
door, window, or gravity air inlet to the
building. The sidewall vent termination must
be at least 8 feet (2.4m) horizontally from any
combustion air intake located above the
sidewall termination cap.
Do not terminate the vent in a window well,
stairwell, alcove, courtyard, or other recessed
area. The vent cannot terminate below grade.
The vent shall not terminate directly above a
public walkway due to the normal formation
of water vapor in the combustion process.
Horizontal terminations must not be located
over areas of pedestrian or vehicular traffic.
The vent system shall terminate at least 1 foot
(0.30m) above grade, above normal snow
levels and at least 7 feet (2.13m) above grade
when located adjacent to public walkways.
The vent terminal shall not be installed closer
than 3 feet (0.91m) from an inside corner of
an L-shaped structure. The vent cap should
have a minimum clearance of 4 feet (1.22m)
horizontally from and in no case above or
below, unless a 4 foot (1.22m) horizontal
distance is maintained from electric meters,
gas meters, regulators and relief equipment.
Flue gas condensate can freeze on exterior
walls or on the vent cap. Frozen condensate
on the vent cap can result in a blocked flue
condition. Some discoloration to exterior
building surfaces can be expected. Adjacent
brick or masonry surfaces should be protected
with a rust resistant sheet metal plate.
DIRECTAIRE AND DIRECT VENT SYSTEMS
Direct Vent and DirectAire Vent Systems are
installed with specific flue pipe material
requirements based on the type of firing
controls used on the unit. Direct Vent and
DirectAire systems both use a separate
combustion air pipe to the outdoors.
The Direct Vent System terminates both the flue
and combustion air inlet in the same pressure
zone. The DirectAire Vent System may
terminate the flue and combustion air inlet in
different pressure zones. The flue outlet and
combustion air inlet may terminate with either
a sidewall or a rooftop termination based on
the specific venting option selected.
DirectAire and Direct Vent Systems
require the
installation of an additional Air Inlet pipe to
supply combustion air from outdoors directly
to the appliance.
L o c h i n v a r
D E S I G N E R
’
S
G U I D E
P O W E R
-
F I N
W A T E R
H E A T E R
6 1 5 - 8 8 9 - 8 9 0 0
1 1
(FIG. 12) LOCATION OF A SIDEWALL VENT TERMINATION
WARNING
No substitutions of flue
pipe or vent cap
material are allowed
when direct venting.
Such substitutions would
jeopardize the safety
and health of building
inhabitants.
