Harman Stove Company HARMAN P68 - Manual (Page 8)

8 P68 Pellet Stove 3-90-00688R24_06/13
venting
A combustion blower is used to extract the combustion
gases from the firebox. This causes a negative pressure in
the firebox and a positive pressure in the venting system as
shown in Fig. 7. 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 possible
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 interior 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. all joints for connector pipe must be
fastened with a minimum of three screws. Follow pellet
vent manufacturer instructions for properly securing
each pellet vent joint. the pellet starting collar must be
secured to the unit's flue collar.
note: simpson duravent Pelletvent Pro harman adapter
Part #3PvP-adhb and Pelletvent Pro harman adapter
increaser Part #3PvP-X4adhb are highly recommended
to be installed on the starter collar to insure a proper
pipe connection to the unit.
venting
iMPortant notice
Approved 3" or 4" Pellet Vent Pipe Such As, Type "PL",
Must Be Used.
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Fig. 7
vent Pipe
Pellet venting pipe (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 1 to 3 inches. The
sections of pipe lock together to form an air tight seal in
most cases. However, in some cases a perfect seal is not
achieved. For this reason and the fact that the P68 operates
with a positive vent pressure we specify that the joints also
be sealed with high temp (rtv) silicone. Aluminum tape
can also be used for any joint that is 1ft. or more from the
outlet of the stove.
avoiding smoke and odors
negative Pressure, shut-down, and Power Failure:
T
o reduce the probability of back-drafting or burn-back in
the pellet burning appliance during power failure or shut-
down conditions, the stove must be able to draft naturally
without exhaust blower operation. Negative pressure in the
house will resist this natural draft if not accounted for in the
pellet appliance installation.
Heat rises in the house and leaks out at upper levels. This air
must be replaced with cold air from outdoors, which flows into
lower levels of the house. Vents and chimneys into basements
and lower levels of the house can become the conduit for air
supply, and reverse under these conditions.
outside air:
hearth & home technologies strongly recommends
attaching outside air in all installations, especially lower
level and main floor locations.
do not install a Flue daMPer in the eXhaust
venting sYsteM oF this unit.
do not connect this unit to a chiMneY Flue
serving another aPPliance.
a chiMneY connector MaY not Pass through
an attic or rooF sPace, closet or siMilar
concealed sPace, Floor , or ceiling. reFerence
local building codes For details.
install vent at clearances sPeciFied bY the
vent ManuFacturer
caution
do not use MaKeshiFt coMProMises When
installing this aPPliance. daMage and/or
injurY MaY result.
= Positive Static Pressure
= Negative Static Pressure
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