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Fan capacity tables are based on standard

air at 70°F and sea level. For other operating

conditions, correct the required Static Pres-

sure (SP) before using the rating tables. The

Brake Horsepower (BHP) is corrected after

the fan selection has been made. Finally,

determine the Class of fan.

Percent Width selections are also available

for the SQAD. Refer to Chicago Blower’s

Fan.net

selection software for exact selections.

EXAMPLE:

Select an SQA fan to handle 15,000

CFM at 3" SP at 500°F and at 2500

feet above sea level.

1.

Refer to Table I. At 2500 feet and 500°F,

the correction factor is 1.98. To simplify

the calculations, use 2.00.

Corrected

SP is 2.00 x 3" SP = 6.00" SP at 70°F

and sea level.

2.

Using the fan rating tables, one fan

selection for 15,000 CFM at 6" SP is a

Size 27. The fan will run at 1797 RPM

and require 20.71 BHP at 70°F and sea

level. (The actual RPM and BHP were

calculated by interpolating between the

14,518 and 15,372 CFM given in the rat-

ing tables.)

3. Correct the BHP. Dividing 20.71 by

the correction factor (2.00). 20.71÷

2.00 = 10.35 BHP at 500°F and 2500'

altitude.

4.

To determine fan construction Class, the

wheel and shaft must be checked for

Maximum RPM using Table II and for

Temperature Deration Factors in Table III.

a. Table III. Divide wheel operating

RPM by the Wheel Deration Factor

for 500°. Wheel RPM at 70°F is

1797 ÷ .82 = 2191. Then divide the

wheel operating RPM by the Shaft

Deration Factor for 500°F. Shaft

RPM at 70°F is 1797÷.97 = 1853.

b. Check Table II for maximum RPMs

for a Size 27 fan. While the required

wheel RPM of 2191 is within safe

limits for a Class I fan, the required

shaft RPM of 1853 is not. The Class

II fan is needed because of high duty

temperature.

12-1/4

13-1/2

15

16-1/2

18-1/4

20

22-1/4

24-1/2

27

30

33

36-1/2

40-1/4

44-1/2

4046

3675

3302

2992

2706

2469

2155

2015

1829

1657

1413

1344

903

817

4983

4520

4067

3633

3285

2997

2653

2446

2219

1928

1643

1412

1043

899

4280

3884

3586

3509

3173

2895

2483

2300

2087

1807

1552

1497

1179

1066

4983

4520

4067

3632

3285

2997

2653

2446

2219

1928

1643

1497

1334

1147

––

––

––

––

––

3359

2943

2674

2425

2166

1970

1700

1541

1394

––

––

––

––

––

3600

3228

3088

2692

2400

2080

1792

1549

1394

3600

3600

3600

3600

3600

3600

1800

1800

1800

1800

––

––

––

––

FAN

SIZE Shaft Wheel Shaft Wheel Shaft Wheel

Wheel

Only

CLASS I

CLASS II

CLASS III

TABLE I

Temperature and Altitude Correction

TABLE II – Maximum RPM at 70° F

Correction factors for temperature (F°) and altitude (above sea level): standard

air = .075 lbs. per cubic foot at sea level, 29.92” barometric pressure and 70° F.

Note: For temperature deration only, not for air performance.

Refer to

Chicago Blower’s

fan.net for performance,

fan curves and

sound data.

For software and

assistance, visit

www.chicagoblower.com

an ISO 9001Company

CHICAGOBLOWERCORPORATION

•1675GlenEllynRoad

•GlendaleHeights, IL

• 60139

fan.net v21.5.51

Description

October 23, 2013

JobDescription:

Bulletin

ChicagoBlowerCorporation

Reference:

SQA

CustomerService

FanType:

SquareFans

Phone: (630) 858-2600

FanModel:

Design 36ASQASWAirfoil

Fax: (630) 858-7172

FanSize:

24 1/2

e-mail:

fans@chicagoblower.com

FanWidth:

100%

Performance

Valuesare in accordancewithAMCAStandard 210

VolumeFlowRate (ACFM)

8000

StaticPressure (IN.WG)

6

Density (LB/FT³)

0.069

Temperature (°F)

100

Altitude (FT)

800

Speed (RPM)

1677

PowerRequired (BHP)

9.35

StaticEfficiency (%)

80.7

OutletVelocity (FT/MIN)

2275

DamperOpening (%)

N/A

ControlType

N/A

OutletArea (FT²)

3.52

MaximumSpeedsat500 °F (RPM)

Class 1Max.RPM

1955

Class 2Max.RPM

2016

Class 3Max.RPM

2545

Sound

Valuesare in accordancewithAMCAStandard 300

ExternalSoundPower Levels (dB):

CenterHz

63

125

250

500

1000

2000

4000

8000

L

wi

Design

90

93

90

87

83

80

77

75

ERC

9

4

1

SoundPressure 3.0FT fromFan (dBA) 82

SoundPressure,Radiated,3.0FT from 0.105 housing 63 dBA.

L

wi

(L

wo

) is sound power at the fan inlet (outlet)/airstream, lessERC.

27

0

5

10

15

20

25

30

0

5

10

15

0

StaticPres. (IN. WG)

FlowRate (ACFM)x1000

0

2

4

6

8

0

5

10

15

0

4

8

12

16

Horsepower (BHP)

0

100

Static Efficiency (%)

Design

PeakPressure

-DesignPoint

-SystemCurve

-PeakPressure

-Powervs.Vol

-SEvs.Vol

CAUTION: FANMUSTNOTOPERATELEFTOF PEAKPRESSURECURVE,EXCEPTFORSTART-U

-15

0

70

100

150

200

250

300

350

400

500

600

650

.79

.87

1.00

1.06

1.15

1.25

1.34

1.43

1.53

1.62

1.81

2.00

2.09

.81

.88

1.02

1.08

1.17

1.27

1.36

1.46

1.56

1.65

1.84

2.04

2.13

.82

.90

1.04

1.10

1.19

1.29

1.39

1.49

1.58

1.68

1.88

2.07

2.17

.84

.92

1.06

1.12

1.22

1.32

1.41

1.51

1.61

1.71

1.91

2.11

2.21

.85

.93

1.08

1.14

1.24

1.34

1.44

1.54

1.64

1.75

1.95

2.15

2.25

.87

.95

1.10

1.16

1.26

1.36

1.47

1.57

1.67

1.78

1.98

2.19

2.29

.

88

.97

1.12

1.18

1.28

1.39

1.49

1.60

1.70

1.81

2.02

2.23

2.34

.90

.99

1.14

1.20

1.31

1.42

1.52

1.63

1.74

1.84

2.06

2.27

2.38

AIR

TEMP

(F°)

29.92

500

29.38

1000š

28.86

1500š

28.33

2000š

27.82

2500š

27.31

3000š

26.82

3500š

26.32

ALTITUDE (feet) with BAROMETRIC PRESSURE (HG)

5

1.00

.94

.90

.86

.82

.79

.78

1.00

1.00

.99

.98

.97

.96

.95

Temp.

(F°)

Deration Factors

TABLE III –

Speed Deration

Steel

Wheel

Steel

Shaft

70

200

300

400

500

600

650

Aluminum same as steel,

max. temperature 200° F.

SQA

SQAD

Fan Selection