Harman Stove Company Accentra Owner's Manual page 16

Fig.27
Fig.28
Venting
#4 Installing into an existing
chimney ( US only )
This method provides excellent venting for normal
operation. This method also provides natural draft in
the event of a power failure. If the chimney condition is
questionable you may want to install a liner as in method
#7.
#5 Installing into an existing
fireplace chimney ( US only )
This method provides excellent venting for normal
operation. This method also provides natural draft in
the event of a power failure.
The damper area must be sealed with a steel plate
or fiberglass. A cap should be installed on the chimney
to keep out rain. If the chimney condition is question-
able you may want to install a liner all the way to the top
as in Method #6.