Harman Stove Company PC 45 Installation And Operating Manual page 8

IMPORTANT NOTICE
Pellet Vent Pipe or PL Vent Pipe Must be used.
+ = Positive static pressure
= Negative static pressure
Fig. 10
Inlet Cover part#
1-10-08542
Fig. 11
8 PC 45 Corn/Pellet Stove
Outside air flex pipe
goes here
Flex pipe part#
2-00-08543
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. 10. 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 system to the stove. The starting col-
lar must be sealed to the stove with high temp
silicone caulking.
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 PC45 operates with a positive vent pres-
sure we specify that the joints also be sealed
with clear silicone.
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 3 feet or more to the side or be-
low the vent pipe outlet. Never terminate the outside
air above the vent pipe outlet. 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.
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.
Vent Pipe
Outside Air
HRV