Outer wall
Inner wall
9. Temporarily insert ducts (included) into the wall
10. Mark where to cut the duct
11. Trim away excess duct & put them back into the wall
12. Seal any gap around the duct with sealant or spray foam insulation.
13. For 4" (10 cm) thick walls, and for round diffusors in the lower duct (the air intake)
Trim 3/4" (2 cm) off the end of the diffusor shaft (as shown).
This will allow additional clearance for the backdraft damper.
14. Install round diffusor into ducts (as shown above).
Duct
Trim away
extra duct
Diffusor
Base of Round
Screws
Round
diffusor
shaft
3/4"
2
10 of 13
