Outside Air - Harman XXV Installation & Operating Manual

Inlet Cover part#
1-10-08542
Fig. 7
Adjustable from 4 1/2" to
10 5/8" wall thickness
Fig. 8
direct Vent wall Passthrough
The Harman Direct Vent Wall Passthrough (Part
# 1-00-677077) makes installing your Harman Pellet
Stove with outside air easier. It combines the needed
wall protection for the venting, with a source of intake
air for combustion. It is made to fit walls from 4 1/2" to
10 1/8" thick with a single square opening in the wall
of 6-1/2 inches.
10
XXV Pellet Stove
Outside air flex pipe
goes here.
Flex pipe part#
1-00-08543 (25')
Outdoor Half
Indoor Half
Venting
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 op-
eration. 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 tech-
nologies strongly recommend attaching outside air
in all installations, especially lower level and main
floor locations.
Per national building codes, consideration must be
given to combustion air supply to all combustion appli-
ances. Failure to supply adequate combustion air for all
appliance demands, may lead to back-drafting of those
and other appliances.
When the appliance is side-wall vented: The air intake
is best located on the same exterior wall as the exhaust
vent outlet and located lower on the wall than the ex-
haust vent outlet.
When the appliance is roof vented: The air intake is
best located on the exterior wall oriented towards the
prevailing wind direction during the heating season.
The outside air connection will supply the demands of
the pellet appliance, but consideration must be given to
the total house demand. House demand may consume
some air needed for the stove, especially during a power
failure. It may be necessary to add additional ventilation
to the space in which the pellet appliance is located.
Consult with your local HVAC professional to determine
the ventilation demands for your house.
To install outside air use 2 3/8" I.D. non-combustible
flex pipe. There is a break-away hole on the rear panel
of the stove which must be removed to connect the flex
pipe. The maximum length run of this pipe is 15 feet. If
a longer run is needed the size must be increased to
3". Inlet cover part number 1-10-08542 should be used
to keep birds, rodents, etc.out of the pipe unless the
Harman wall passthrough is being used.