INSTALLATION INSTRUCTIONS
(continued)
8
Plan the Ductwork
1. This downdraft blower system is designed
for use with 31⁄4″x 10″ductwork (can be transitioned
to 6″round). Three different discharge
directions are available with side--to-side
adjustment for accurate alignment of ductwork.
2. For best performance: Choose the ducting
option which allows the shortest length of
ductwork and a minimum number of elbows and
transitions. Check location of floor joists, wall
joists, wall studs, electrical wiring or plumbing
for possible interference.
NOTE: The unit is shipped with the 31⁄4″x 10″
discharge facing DOWN. See the Changing
Blower Direction section, if necessary.

Steps to 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. Ensure that the total equivalent length of
ducting does not exceed the maximum
recommendation of 100 feet.
Right
discharge
Down discharge
(as shipped)
Left discharge
Duct Pieces Equivalent Length* Duct Pieces Equivalent Length*
31⁄4″x 10″
6″Round to 6″Round 5 ft.
Straight 1 ft. (per foot length) Transition
6″Round
to 31⁄4″x 10″
31⁄4″x 10″1 ft. (per foot length) Transition 20 ft.
Straight 90° Elbow
31⁄4″x 10″
to 6″Round
6″15 ft. Transition 12 ft.
90° Elbow 90° Elbow
6″Round
6″Wall Cap 21 ft.
45° Elbow 9 ft. with Damper
31⁄4″x 10″
31⁄4″x 10″Wall Cap 27 ft.
90° Elbow 16 ft. with Damper
31⁄4″x 10″6″Round
45° Elbow 5 ft. Roof Cap 20 ft.
31⁄4″x 10″6″Round
90° Flat Elbow 24 ft. Roof Vent 24 ft.
6″Round
to 31⁄4″x 10″7 ft.
Transition
SHOULD NOT EXCEED 100 EQUIVALENT FT.
*Equivalent lengths of duct pieces are based on actual tests conducted by
GE Evaluation Engineering and reflect requirements for good venting
performance with a downdraft rated at 500 CFM.
291/2″
Venting Island to Outside Wall
Wall
7″
24″Power
Cord provided
(on-right-hand side)