Installation Instructions and User Guide
6
VENTING REQUIREMENTS
Determine which venting method is best for your application. Ductwork can extend
either through the wall or the roof.
The length of the ductwork and the number of elbows should be kept to a minimum
to provide efficient performance. The size of the ductwork should be uniform. Do not
install two elbows together. Use duct tape to seal all joints in the ductwork system. Use
caulking to seal exterior wall or floor opening around the cap.
Flexible ductwork is not recommended. If it is used, each foot of flexible ductwork
used is equivalent to two feet of straight metal ductwork when calculating the ductrun
length. Thus, a flexible elbow equals two standard elbows.
Make sure there is proper clearance within the wall or floor for exhaust duct before
making cutouts. Do not cut a joist or stud unless absolutely necessary. If a joist or stud
must be cut, then a supporting frame must be constructed. For best results, internal
blowers should use 6” (152mm) round ducting and remote blowers should transition
to 10” (254mm) round duct as soon as possible. If small ducting is used, it should be
transitioned to 10” (254mm) round as soon as possible.
WARNING!
To reduce the risk of fire, use only metal ductwork.
CAUTION!
To reduce risk of fire and to properly exhaust air, be sure to duct air outside – do not
vent exhaust air into spaces within walls or ceilings or into attics, crawl spaces or
garages.
Cold weather installations (not included)
An additional back draft damper should be installed to minimize backward cold air flow
and a nonmetallic thermal break should be installed to minimize conduction of outside
temperatures as part of the vent system. The damper should be on the cold air side of
the thermal break. The break should be as close as possible to where the vent system
enters the heated portion of the house.
!
WARNING!
Venting system MUST terminate outside the home.
DO NOT terminate the ductwork in an attic or other enclosed space.
DO NOT use 4” (102 mm) laundry-type wall caps.
Flexible-type ductwork is not recommended.
DO NOT obstruct the flow of combustion and ventilation air.
Failure to follow venting requirements may result in a fire.