Outside Air - Harman PP38+ Installation & Operating Manual

iMPortant notice
Approved Pellet Vent Pipe Such As, Type "L"
Or "PL", Must Be Used.
-
+
= Positive Static Pressure
-
= Negative Static Pressure
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. The use of a starting collar is not
always necessary. The first piece of pipe must be
fastened securely with at least 2 fasteners to the flue
collar of the stove. The two screws provided are a
self-drilling style, however, due to material thickness,
drilling a 3/32" pilot hole is recommended.
+
+
Fig. 7
venting
vent Pipe
Pellet vent pipe (known as L or 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. Follow
vent manufacturer's guidelines and instructions.
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 PP38+ operates with a positive vent pressure we
specify that the joints also be sealed with silicone.
Aluminum tape can also be used for any joint that is 1
ft. or more from the outlet of the stove.
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.
a chiMneY Must be oF a tYPe suitable
For solid Fuel.
chiMneY
Maintained in good condition and KePt
clean.
avoiding smoke and odors
negative Pressure, shut-down, and Power
Failure:
To 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:

harman home heating and hearth & home
technologies recommend attaching outside air in
all installations, especially lower level and main
floor locations.
and connector
PP38+ Pellet Stove
Must be
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