Downdraft Ventilators
Page 3
1. The interior
downdraft blower
system is designed
for use with 3-1/4" 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
RIGHT
DISCHARGE
DOWN DISCHARGE
LEFT
DISCHARGE
PLAN THE DUCTWORK
Interior Blower Installation Exterior Blower Installation
EQUALS 8 FT. OF
STRAIGHT DUCT
6" ROUND
ELBOW
EQUALS 14 FT. OF
STRAIGHT DUCT
3. The system will operate most efficiently when the ductwork
does not exceed 40 feet of equivalent duct. The chart, above,
shows equivalent feet of elbows and transitions. The number
of feet of straight duct plus the equivalent feet of transitions
and/or elbows to be used should equal 40 feet or less.
NOTE: The equivalent feet of various roof and wall caps has
been taken into consideration. Do not include them in this
calculation.
3-1/4" X 10" TO 6" RD.
TRANSITION 3-1/4" X 10"
90O ELBOW
elbows and transitions. Check location of floor joists, wall
studs, electrical wiring or plumbing for possible interfer-
ence.
EQUALS
2 FT. OF
STRAIGHT DUCT
1. The exterior
downdraft blower
system is designed
for use with 3-1/4" x
14" ductwork (can be
transitioned to 8"
round). Three
different discharge
directions are
available with side-
to-side adjustment for
accurate alignment of
ductwork.
2. For best perfor-
mance: Choose the
ducting option which
allows the shortest
length of ductwork
and a minimum
RIGHT
DISCHARGE
DOWN DISCHARGE
LEFT
DISCHARGE
EQUALS 11 FT. OF
STRAIGHT DUCT
8" ROUND ELBOW
EQUALS 19 FT. OF
STRAIGHT DUCT
3. The system will operate most efficiently when the ductwork
does not exceed 40 feet of equivalent duct. The chart, above,
shows equivalent feet of elbows and transitions. The number
of feet of straight duct plus the equivalent feet of transitions
and/or elbows to be used should equal 40 feet or less.
NOTE: The equivalent feet of various roof and wall caps has
been taken into consideration. Do not include them in this
calculation.
3-1/4" X 14" TO 8" RD.
TRANSITION 3-1/4" X 14" 90O
ELBOW
number of elbows and transitions. Check location of floor
joists, wall studs, electrical wiring or plumbing for possible
interference.
EQUALS
5 FT. OF
STRAIGHT
DUCT
Interior Blower Installation Exterior Blower Installation
TAKE MEASUREMENTS (CONTINUED)
SIDE VIEW
OF DOWNDRAFT SIDE VIEW
OF DOWNDRAFT