Installation Guide
4
HOOD EXHAUST
The following chart describes an example of one possible 
ductwork installation.
NOTE: Read these next two pages only if you plan to vent your exhaust to the 
outside. If you plan to recirculate the air back into the room, proceed to page 6.
OUTSIDE TOP EXHAUST (EXAMPLE ONLY)
NOTE: For back exhaust, care should be taken to align exhaust with space between studs, or wall should be prepared at 
the time it is constructed by leaving enough space between the wall studs to accommodate exhaust.
 EQUIVALENT   NUMBER  EQUIVALENT
DUCT PIECES    LENGTH x    USED    =  LENGTH
      Roof Cap    24 Ft.    x  (1)    =  24 Ft.   
      12 Ft. Straight Duct  12 Ft.    x  (1)    =  12 Ft.     
   (6” Round)
   Rectangular-to-Round 5 Ft.  x (1)  = 5 Ft.  
   Transition Adaptor* 
Equivalent lengths of duct pieces are based on actual tests and 
reflect requirements for good venting performance with any vent hood.
  Total Length  =  41 Ft.
*IMPORTANT: If a rectangular-to-round transition adaptor is used, the bottom corners of the damper will have 
to be cut to fit, using the tin snips, in order to allow free movement of the damper.
The following chart describes an example of one possible 
ductwork installation.
Installation Instructions
OUTSIDE BACK EXHAUST (EXAMPLE ONLY)
 EQUIVALENT   NUMBER  EQUIVALENT
DUCT PIECES    LENGTH*  x  USED    =  LENGTH
      Wall Cap    40 Ft.    x  (1)    =  40 Ft. 
      3 Ft. Straight Duct  3 Ft.    x  (1)    =  3 Ft.   
(3¼
”
 x 10
”
 Rectangular)
   90° Elbow  10 Ft.  x (2)  = 20 Ft.  
Equivalent lengths of duct pieces are based on actual tests and 
reflect requirements for good venting performance with any vent hood.   
 Total Length  =  63 Ft.










