Ductwork Preparation - Thermador PROFESSIONAL HPCN36NS Manuel D'installation

Wall Framing
Due to the weight of the hood, make sure the wood
mounting bracket is attached to all available wall studs.
Framing must be fastened together and to ceiling joists to
provide enough structural strength to support the weight of
the hood and internal blower, if applicable.
Wall framing should be, at minimum, made of 2" x 4"
lumber. Proper structural support is required to
accommodate the weight of the hood.

Ductwork Preparation

Discharge Direction
The exhaust air is discharged upwards through a duct or
directly through the outside wall into the open.
The hood can be mounted on the wall only with a vertical
discharge.
Ducting Recommendations
Proper performance is dependent upon proper ducting.
Local building codes may require the use of make-up air
systems when using ducted ventilation systems greater
than speci ed cubic feet per minute (CFM) of air
movement.
The speci ed CFM varies from locale to locale. It is the
responsibility of the owner and the installer to determine if
additional requirements and/or standards apply to specific
installations.
DO NOT USE FLEXIBLE DUCT; it creates back pressure/
air turbulence and reduces performance.
Always install a metal vent cover where the ductwork exits
the house.
COLD WEATHER installations should have an additional
backdraft damper installed to minimize reverse cold air flow
and a nonmetallic thermal break to minimize conduction of
outside temperatures as part of the ductwork. The damper
should be on the cold air side of the thermal break. The
break should be as close as possible to where the ducting
enters the heated portion of the house.
English 6
MAKE-UP AIR: Local building codes may require the use
of make-up air systems when using ducted ventilation
systems greater than specified CFM of air movement. The
specified CFM varies based on locale. It is the
responsibility of the owner and the installer to determine if
additional requirements and/or standards apply to specific
installations.
WARNING!
Vent ducting directly outdoors (not into an attic,
underneath the house, into the garage or into any
enclosed space).
The unit cannot be used in conjunction with a recirculation
unit.
THERMADOR recommends not exceeding 50 ft (15.24 m)
of duct.
Keep duct runs as short and straight as possible. Elbows
and transitions fittings reduce air flow efficiency. Back to
back elbows and "S" turns give very poor delivery and are
not recommended. A short straight length of duct at the
inlet of a remote blower gives the best delivery.
Hoods are supplied with a 10" (254 mm) round transition. A
locally supplied transition is required for other sizes.
Use "Equivalent Duct Lengths for Commonly Used
Transitions" on page 7 to compute permissible lengths for
duct runs to outdoors.