Harman Stove Company XXV Installation & Operating Manual page 9

iMPOrtant nOtice
Approved Pellet Vent Pipe (3" or 4") Must Be Used unless
installing with the optional top 6" Flue Adapter.
If using 6" Flue Adapter, it is recommended to use a sealed
seam 6" flue pipe (snaplock seam is not recommended)
secure each joint with at least 3 screws, and seal with high
temperature silicone.In some cases it may be necessary
to use a liner in the existing chimney to obtain proper draft.
cautiOn
dO nOt cOnnect tO anY air diStributiOn duct
Or SYSteM.
_
+
= Positive Static Pressure
_
= Negative Static Pressure
Fig. 6
inStall Vent at clearanceS SPeciFied bY the
Vent ManuFacturer.
3-90-00684R22_04/13
Venting
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. 6. 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. The use of a starting collar is not always
necessary. The first piece of pellet vent pipe must be fastened
to the appliance flue collar with at least 3 fasteners. The
fasteners provided are a self-drilling type, however, due to
material thickness, drilling a 3/32" pilot hole for each screw
is recommended. Follow vent manufacturer's instructions for
proper connection at each joint.
Vent Pipe
Pellet venting pipe (Known as "L" or "PL" venting) is
constructed of two layers with air space between the layers.
This air space is an insulator which reduces the surface
temperature and allows a clearance to combustibles of 3
inches or less. 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 XXV operates with a positive vent pressure we specify
that the joints also be sealed with silicone.
All joints for connector pipe must be fastened or secured with
a minimum of three screws. We cannot emphasize enough,
the importance of sealing every seam and joint in the venting
system which is inside the home. Even the smallest pin hole
can leak and when it does you will smell wood smoke or a
creosote smell in the room. If this occurs check for leaks.
Leaks are easiest to see during start-up. Alternatively you
can use a smoke pellet to leak test the venting before lighting
your first fire.
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.
9
XXV Pellet Stove