Harman Stove Company Accentra 2 Installation And Operating Manual page 13

IMPORTANT NOTICE
Pellet Vent Pipe or PL Vent Pipe Must be used.
Fig.22
+ = Positive static pressure
= Negative static pressure
Fig. 23
Inlet Cover part#
1-10-08542
Venting
Room Sensor
Connection Ports
Outside air flex pipe
goes here
3" PL vent pipe
flue collar
Flex pipe part#
2-00-08543
Fig. 24
Venting
A combustion blower is used to extract the com-
bustion gases from the firebox. This causes a nega-
tive pressure in the firebox and a positive pressure
in the venting system as shown in fig. 22. The longer
the vent pipe and more elbows used in the system,
the greater the flow resistance. Because of these
facts we recommend using as few elbows as pos-
sible and 15 feet or less of vent pipe. The maximum
horizontal run should not exceed 48". If more than
15 feet of pipe is needed, the diameter should be
increased from 3" to 4" because a larger pipe causes
less flow resistance. Be sure to use approved
pellet vent pipe wall and ceiling pass- through
fittings to go through combustible walls and
ceilings. Be sure to use a starting collar to attach
the venting systen to the stove. The starting collar
must be sealed to the stove with high temp sili-
cone caulking.
Vent Pipe
Pellet venting pipe (also known as PL vent is
constructed of two layers with air space between
the layers. This air space acts as an insulator and
reduces the outside surface temperature to allow a
clearance to combustibles of only 3 inches. The
sections of pipe lock together to form an air tight
seal in most cases; however, in some cases a per-
fect seal is not achieved. For this reason and the
fact that the Accentra operates with a positive vent
pressure, we specify that the joints also be
sealed with clear silicone.
Outside Air
Outside air is optional except in mobile homes
and where building codes require. The benefit of
outside air is mainly noticed in small, very tight
houses.
To install outside air use 2 3/8" I.D. flex pipe
part number 2-00-08543. There is a break-away hole
on the rear panel which must be removed before
connecting the flex pipe. The pipe should be run out-
side and terminate to the side or below the vent pipe
outlet so the flue outlet is more than 12" from the
inlet cover. The maximum length run of this pipe is
15 feet. If a longer run is needed, the size must be
increased to 3". Inlet cover part number 1-10-08542
should be used to keep birds, rodents, etc.out of
pipe.
HRV
When installing in a house with a Heat Reclaim-
ing Ventilation System (HRV) be sure the system is
balanced and is not creating a negative pressure in
the house.
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