

Design
Features
Rugged
Steel
Housing
and Pedestal
The
high grade
steel
housing
and drivetrain
pedestal
is
continuously
welded
by
welders
certified
to
American
Welding
Society
(AWS)
code standards
for
maximum
strength
and
rigidity.
Structural
steel
stiffeners
are
added
to
further
increase
strength.
The drivetrain
pedestal
is
an
A-frame
design
that is wider
at
the bottom than
at
the
top
to
increase
stability
in
the
foundation
and resist
vibration.
Long
Bearing
Life
The
bearings
are
anti-friction
ball
or
spherical
roller
with
pillow
block
housings
and
are
available
with
grease
or
oil
lubrication.
They
are
sized
for
a
minimum
L-10
life
of
40,000
hours
at
class maximum
speed
and
motor
horsepower.
Since
most
applications
do
not
operate
at
either class maximum
speed
or
motor
horsepower,
the
actual
bearing
life
is
much
longer.
Maximum Fan
Efficiency
Grade
FEG
The
Design
95
is rated
with
the
highest
Fan
Efficiency
Grade
(FEG)
of
90,
in
accordance
with
the
Air
Movement
Control
Association
(AMCA)
Publication
205.
FEG
is
a
classification
for
industrial
fans
which
grades
the
fan's
peak
mechanical
efficiency
relative
to
its wheel diameter.
A
higher
FEG
means a more
efficient fan.
Each
performance
table
on
pages
8
through
16
is
labeled
with
the
FEG
90
rating.
Precision
Shafts
All
shafts
are
made
from
1045
cold rolled steel
or
equivalent.
The
shafts
are
turned,
ground,
and
polished
to
assure
tight bearing
and hub
fit.
Shafts
are
sized
so
the
fan
running
speed
is
30%
or more
below the
first
critical
speed
to
avoid
resonance
and
minimize vibration.
Backward
Curved
Advantage
Chicago's
backward curved wheel consists
of
solid
steel
blades
continuously
welded
to
a
streamlined wheel
sideplate
and
heavy
steel
backplate.
They
can
withstand
temperatures
to
800°F.
The backward curved wheels
have
true
non-overloading
horsepower
characteristics
with
a
steep
stable
pressure
curve
and mechanical
efficiencies
over
84%.
Inlet
Cone
Punched
Outlet
Shaft
and
Bearing
Guard
Punched
Flanged
Inlet
Split
Housing
Backward
Curved
Wheel
3