DFO-103 - page 7

Select a fan for 43,000CFMwithamaximumoutlet velocityof 3200FPM.
Fromthe table, the first fanwithanoutlet areaof at least 13.44Ft
2
is the
Size 365.With an outlet velocity of 13.79 Ft
2
, theSize 365will meet the
maximumoutlet velocity specified.
Theactual velocitywill be:
Havingsized the fanbasedonoutlet velocity, turn to themulti-rating table
on the page indicated, either Design 51 or Design 51 RA. Locate the
speed and horsepower required to meet the CFM and static pressure
specified.
Example:
7
Many engineers specify a maximum fan outlet velocity. Chicago’s Quick
Selection Method provides the smallest possible fan size that meets any
specifiedoutlet velocity limit.
To size a fan with a specified maximum outlet velocity (O.V.), calculate a
minimum fan outlet area (O.A.) using the formula below. Then select a
fan from the table at right with an outlet area equal to or larger than the
calculatedminimum.
RequiredVolime inCubic
Feet PerMinute, CFM
SpecifiedMaximumO.V. in
Feet PerMinute, FPM
= MinimumO.A. inSquareFee, Ft
2
= 13.44Ft
2
Refer toChicagoBlower’s
SelectionProgram,
fan.net
,
for performance, fan
curvesandsounddata.
Contact your local
ChicagoBlower sales
engineer for software
andassistance.
ForFanswithSpecified
OutletVelocities
43,000
3,200
= 3118FPM
43,000
13.79
CFM
Ft
2
OutletAreasand
PageNumbers
1,2,3,4,5,6 8,9,10,11,12,13,14,15,16,17,...52
Powered by FlippingBook