Harman PB 105, Installation & Operating Manual, Page: 13 / 40

13
Outside Air
Outside air is optional, although it may be
required by some building codes. The benefit of
outside air is higher efficiency and reduced venting
restrictions.
To install outside air, use 2 3/4” I.D.galvanized
steel flex pipe, part # 2-00-08544 ( 12’ 6” length) or
part # 2-00-08545 ( 25’ length) See Fig. 6. There is
a break-away hole on the rear panel which must be
removed before connecting the flex pipe. See Fig.
7. The pipe should be run outside and terminate 3
feet or more below or 1 foot or more to the side of
the vent pipe outlet. Never terminate the outside air
above the vent pipe outlet. The maximum length of
this pipe is 20 feet. Inlet cover part number 1-10-
09542 should be used to keep birds, rodents etc.out
of the inlet pipe. See Fig.6.
NOTE: If outside air is installed, the inlet cover
should not be placed in an area where drifting of
snow or ice will build up, blocking the intake air
supply.
The Outside Air knockout is located on the face
of the Feeder Cover. It is pre-cut except for several
small tabs. There is also a filler plate screwed to the
inside to cover the top of the hole after the Outside
Air Pipe has been installed. This will allow for re-
moval of the Feeder Cover without disconnecting
the Outside Air Pipe. See Fig. 7.
Only metal Intake Flex should be used for the
Outside Air Supply connection.
The Outside Air Intake Pipe is inside the Feeder
Cover and to the right of the feeder motor. The 2
3/4” steel flex pipe is made to slide over the outside
of the Air Intake Pipe. See Fig. 8. It should be held
into place with some silicone, foil tape, or a hose
clamp. (not supplied)
Heat Reclaiming Ventilation System
(HRV)
When installing in a house with a Heat Reclaim-
ing Ventilation System (HRV) be sure the system is
balanced and is not creating a negative pressure in
the house.
Inlet Cover part#
1-10-09542
NOTE: If the boiler is installed with the out-
side air system no adjustments to the HRV should
be necessary.
Installation
Fig. 6
Fig. 7
Fig. 8
Outside Air Pipe
Knockout
Feeder Cover
Hopper/Feeder
Swing Plate
Knob
Outside Air Inlet Pipe