Step 5C
Determine Flexible Ducting’s Equivalent Length
1.
Measure the actual amount of offset
(maximum 3
″
recommended). The effect upon
airflow is dependent upon the amount of offset.
2.
Calculate the equivalent ducting allowances
using:
(___ in. offset) x (14 ft. per inch)
= ___ ft. equivalent length.
3.
Enter the calculated value into TABLE 1 of
this Installation Instruction.
4.
Ensure that the total equivalent length of
ducting does not exceed the maximum
recommendation of 100 feet.
33
Install ductwork, making male-female
connections in direction of airflow as shown.
Secure all joints with sheet metal screws and
duct tape to assure airtight seal.
Select downward or wall venting. To convert
blower exhaust direction, remove four nuts
inside the plenum which hold blower and wire
finger guard. Remove blower and rotate so that
exhaust faces downward or rear direction, as
needed. Replace wire finger guard and nuts.
Retighten nuts.
Blower exhaust direction can be adjusted
slightly while in its vertical or horizontal
direction by loosening four nuts holding blower,
rotating blower and retightening nuts.
Use the shortest and straightest duct run
possible. For satisfactory performance the duct
run should not exceed 100 feet equivalent
length. Refer to TABLE 1 of equivalent lengths.
Use TABLE 1 to calculate the total equivalent
length of the ductwork.
Step 6
Installing the Ductwork
Use minimum 26 gauge galvanized or 24 gauge
aluminum duct in 6
″
round or 3
1
⁄
4
″
x 10
″
size, or
combination of both.
PVC duct should be used if installing under
a poured concrete slab.
NOTE:
Local building code must be followed in
specifying approved type and schedule of PVC
duct used.
Although it is not recommended, 5
″
round duct
may be used on SHORT DUCT runs. But, note
higher equivalent lengths for each 5
″
dia. piece
used.
Always use an appropriate roof or wall cap with
damper. Laundry type wall caps should NEVER
be used.
Thru Cabinet Toe Space
Between Floor Joist
Downward Venting
Inside Wall to Roof
Direct to Outside
Rear Wall Venting
(continued next page)
Duct Tape Over Seam
and Screw
Screw
Air
Flow