6
To calculate the length of the system you need, deduct the equivalent feet for each vent piece used in the
system from the recommended maximum duct run.
Duct Run Calculation:
Recommended maximum run
6” or 3-1/4 x 10” duct
50 ft
Vent piece deduction
Each 90º elbow used
9 ft
Each 45º elbow used
5 ft
Each 6” to 3/14 x 10” transition used
7 ft
Side wall cap with damper
0 ft
Roof cap
0 ft
Duct Run Calcuation example:
One roof cap, two 90º elbow, and one 45º elbow used:
0ft + 9ft + 9ft + 5ft = 23ft used.
Deduct 23ft from 50ft, 27ft maximum available for
straight duct run.
IMPORTANT:
•
A minimum of 6 inch round
1
(standard for this range hood) ) must be used to maintain maximum airflow
efficiency.
•
Always use rigid type metal/aluminum ducts if available to maximize airflow
•
Please use Duct Run Calculation below to compute the total available duct run when using elbows,
transitions and caps.
•
ALWAYS, when possible, reduce the number or transitions and turns. If long duct run is required, increase
duct size from 6 to 7 or 8 inch
1
. If a reducer is used, install a long reducer instead of a pancake reducer.
Reducing duct size will restrict and decrease airflow, thus reduce duct size as far away from opening as
possible.
•
If turns or transitions are required, install as far away from opening and as far apart as possible.
•
Minimum mount height between stove top to hood bottom should be no less than 28 inches* for
electric ranges and 30 inches* for gas ranges.
•
Maximum mount height between stove top to hood bottom should be no higher than 31 inches* for
electric ranges and 36 inches* for gas ranges.
•
It is important to install the hood at the proper mounting height. Hoods mounted too low could result
in heat damage and fire hazard; while hoods mounted too high will be hard to reach and will loose
performance and efficiency.
•
If available, also refer to stove top manufacturer’s height clearance requirements and recommended
hood mounting height above range.
Minimum Duct Size:
•
Round 6 inch minimum
1
* Due to different ceiling height configurations, recommended height may not be applicable.
1
Turin Sorrento 48 Inch (TU18784-48) requires an 8 in duct.
4. CALCULATING VENT SYSTEM HEIGHT