Harman PP38+ User Manual

9
PP38+ Pellet Stove

  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. 
    
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 

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 rst re.



T      
      
  
 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 ows 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.

      

      



Approved Pellet Vent Pipe Such As, Type "L"
Or "PL", Must Be Used.

A combustion blower is used to extract the
combustion gases from the rebox. This causes
a negative pressure in the rebox 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 ow 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 ow resistance. 


The use of a starting collar is not
always necessary. The rst piece of pipe must be
fastened securely with at least 2 fasteners to the ue
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.
       

    


= Positive Static Pressure
= Negative Static Pressure
+
-
Fig. 7




Harman PP38+ Specifications

General

Brand	Harman
Model	PP38+
Category	Pellet stove
Language	English