Installation Instructions Revised 10/13/2015 Copyright (C) 2008 Proverbs 22:29 Page 10
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In-line dampers must be installed so that the exhaust air flow will open the butterfly blades.
For
horizontal duct runs
, the in-line damper must be installed so that the hinge between the two
butterfly blades is
vertical
—the hinge pin must point up and down. Otherwise, because of gravity,
the damper’s blades will not close and the damper will not prevent backdrafts.
For
vertical duct runs
, the in-line damper’s hinge will be
horizontal
(sideways), which is correct for
vertical duct runs. Gravity will help close the damper blades after each use.
For
upward slanted duct runs
, the in-line damper’s hinge must point to the top and bottom sides of
the duct. In his position, gravity will help close the damper blades after each use. Otherwise, because
of gravity, the damper’s blades will not close and the damper will not prevent backdrafts.
5.
Roof Caps and Wall Caps
The roof cap or wall cap is the termination point of the venting system that allows the exhaust air to exit to
the outdoors. All sections of this fitting must have an equal or greater air path area than the ventilator’s
discharge port. If any section of the roof cap or wall cap is smaller than the ventilator’s discharge port, the
entire ventilation system will lose efficiency and the restriction will cause increased static pressure.
IMPORTANT:
Even though the intake side of the roof cap or wall cap may be properly sized, roof caps or wall
caps with built-in dampers must be made so that when the damper is fully open, the actual open area of the
final air path is equal to or greater than the discharge port of the ventilator. Any undersized portion of a roof
cap or wall cap will cause excessive static pressure that may result in rattling, vibration and air buffeting
noises, as well as inadequate ventilation.
Roof caps and wall caps must have an integral bird screen.
6.
Attaching Duct to House Framework
The ventilation system should be attached to the framework in such a manner that the weight of the duct and
fittings is supported with no stress on the duct joints, fittings or on the ventilator. All ducting should be
attached so as to avoid any possible duct vibration from being transferred to the house’s framework.
7.
Hoods with Optional Top or Back Venting
Several range hood models provide the option of venting the exhaust air out the top or back side of the range
hood. On some models, this is accomplished by redirecting the motor/blower unit to exhaust through the
top, back or the recirculation position. On other models, the duct pipe is attached directly to the start collar
which can be attached to the top side or back side of the hood. For more details on this aspect of the
installation, see the detailed Installation Instructions packaged with each unit.
IMPORTANT
: On models with multiple venting ports, the open holes/slots around the unused venting port(s)
MUST BE SEALED with Aluminum Foil Metal Duct Tape
. Otherwise, exhaust air and smoke will be vented
through the unused Vent Knockout’s holes/slots. On models featuring the recirculation option, if this option
is NOT used, the vent port inside the hood should also be taped over with Aluminum Foil Metal Duct Tape.
UNUSED PORTS SHOULD BE TAPED BEFORE THE RANGE HOOD IS MOUNTED TO THE WALL OR CABINET
.
8.
Liners Using Optional Vent Transition Accessory
On installations using the optional vent transition accessory to transition to 10” round duct, all bottom edges
of the transition should be taped to the liner with 2 – 3 layers of Aluminum Foil Metal Duct Tape.
