Thermador Professional Serie Instructions D'installation page 10

en-us Preparing the installation
Preparing the installation 4 Preparing the installation
Preparing the installation
4.1 Ductwork preparation
The exhaust air is discharged upwards through a duct
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or directly through the outside wall into the open.
The appliance can be mounted on the wall only with a
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vertical discharge.
Proper performance is dependent upon proper ducting.
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Local building codes may require the use of make-up air
systems when using ducted ventilation systems greater
than specified cubic feet per minute (CFM) of air.
The specified CFM varies from locale to locale. It is the
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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
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pressure/air turbulence and reduces performance.
Always install a metal vent cover where the ductwork
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exits the house.
The appliance must be vented to the outside of the
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building only.
COLD WEATHER installations should have an
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additional backdraft damper installed to minimize
backward 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.
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MAKE-UP AIR: Local building codes may require the
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use of make-up air systems when using ducted
ventilation systems greater than specified CFM of air
movement. The specified 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.
To reduce risk of fire and to properly exhaust air, be
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sure to duct air outside. Do not vent exhaust air in
spaces with walls or ceilings or into attics, crawl spaces
or garages.
Thermador recommends not exceeding 50 ft (15.24 m)
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equivalent of duct.
Keep duct runs as short and straight as possible.
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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
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blower gives the best delivery.
Hoods are supplied with a 10" (254 mm) transition. A
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locally supplied transition is required for other sizes.
Use the "Equivalent duct lengths for commonly used
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transitions" table to compute permissible lengths for
duct runs to outdoors. → Page 11