Heatilator BIR42 Owner's Manual page 25

and return
WARNING! Risk of Fire!
air space clearance to insulation and other combustible
Offsets/Returns
Chimney Sections*
6 ft
NOTICE:
6 ft
CAUTION! Risk of Fire and/or Asphyxiation! DO NOT
mm
20 ft (6.10 m) max.
pipe between an
offset & return
Ceiling firestop
(2477 mm)
DO NOT connect to any air distribution duct
14-11
Transition
97 1/2 in.
Effective
Height
6 ft (1.83 m) max.
unsupported chimney
above roof
35 ft (10.7 m)
max. straight
unsupported
chimney height
18.5 ft (5.64 m)
min. height
single offset-return
90 ft (27.4 m)
max. height