Thermador HMWN30 Manuel D'installation page 8

For safety reasons, ducting should vent directly outdoors (not into an attic, underneath the house, into the
garage or into any enclosed space).
Keep duct runs as short and straight as possible.
Duct fittings (elbows and transitions) 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 the remote blower gives the best delivery.
Transition to duct from the integral blower to remote duct transition as close as possible.
In order opreference, use:
1st. 10" round duct
2nd. 8" round duct
3rd. 3-1/4" x 14" duct
4th. 7" round duct
5th. 3-1/4" x l0" duct
6th. 6" round duct
The use of flexible metal round duct should only be used when no other duct fitting exists. Limit use to short
and do not crush when making corners.
lengths
1. Prepare duct and conduit cut outs, see figures
1 and 2 as needed.
22
10-1/2
Figure 1
23-1/8"
Figure 2
TABLE 2. DUCTWORK INSTALLATION GUIDELINES
30" 36"
Model
X
4-9/16" 10-9/16"
2-3/4"
X
5- 7/8"
Assembly of the 10" transition:
2.
The transition supplied with the hood mounts to
the top.
Do not install transition until hood is
48"
fixed on cabinet or wall.
a. Place the transition piece over the hood
outlet and secure with 4 screws provided.
(Figure3)
b. Wrap all joints (metal transition and hood)
with duct tape for an airtight seal.
c. Remove tape holding damper.
Hood outlet
Figure 3
Screws (4)
8
Transition