Harman Stove Company Accentra-2 Installation And Operating Manual page 18

It is recommended that
outside air be installed with this
venting configuration to reduce
smoke and creosote smell in the
room in the event of power failure.
Through the ceiling vent, follow PLvent
manufacturers recommendations when using wall
and ceiling pass through. Note: Do not place joints
within wall pass-throughs.
12" min. wall to outlet
36" min clearance to any
combustible material
Shaded area represents the
minimum clearance to combustible
materials such as shrubery,
mulch or tall grasses.