Harman® • PF-120 Installation Manual_R1 • 2014 -___ • 03/14
7
3-90-08121i
NOTE: All Clearances are Minimum Clearances
If installing the furnace in a room separated from the
remaining living spaces, the minimum size of the room must
be no smaller than 8’ x 8’. Figure 3.2. The reason for this
is heat build-up and required space for service and normal
operation. This is the minimum size of the room even if it is
built of non-combustible material.
High and low air vents MUST be installed between the room
and the remaining living space. Each vent should be at least
72 square inches in area. ( The vent size will need to be
increased if there is no return air ducting system.)
The striped areas are the minimum clearances to combustibles
which is 36” from stove body, not the hopper or blower.
The shaded area indicates the required floor protection area.
The furnace requires 48” x 52” of floor protection centered
around the skid plate footprint. Flooring should be a minimum
of 26 gauge sheet metal covering the installation clearance
area and 18” in front of, and 8” to either side of the ash pan
door.
The 18” clearance from the hopper end is a manufacturer’s
recommendation for adding pellets and/or servicing the
feeder mechanism.
The minimum clearance to the top of the plenum is 4”. Fig. 3.3
Note the minimum height to the bottom of the supply duct if
it crosses the hopper.
The minimum duct configuration to a living space above the
furnace is as shown below. An offset of at least 24” MUST
be installed between the plenum and the floor register. The
register size MUST have an area of at least 240 square
inches.
The minimum ceiling height is 6’6”. This is set by the
clearance to combustibles (28”) from the top of the of
the furnace. See Figure 3.3.
NOTE: Install vent at clearances specified by the vent
manufacturer.
Figure 3.2
B. Clearances to Combustibles
Floor Protection
96” Minimum
96” Minimum
48” Wide
52” Long
18”
12”
18”
36”
1”
1”
64.5”
36”
When installing a floor register, the
temperature of the discharge air
MUST be taken into consideration
(The discharge air temperature may
be high enough to cause burns if not
properly operated and maintained.)
CAUTION
!
The Blower Motor full load AMPS
MUST be checked. A plenum damper
may be required to adjust the motor
full load AMPS to the motor nameplate
rating.
CAUTION
!
24”
28”
65.5”
1”
Min. 78”
Ceiling Height
24”
1”
4”
12”
36”
Figure 3.3
