7

Blower capacity tables are based on

standard air at 70°F and sea level.

For other operating conditions,

correct the required Static Pressure

(SP) before using the rating tables.

The BrakeHorsepower (BHP) is

corrected after blower selection

has beenmade.

Refer to the Temperature/Altitude

table. At 1000 feet and 100°F, the

correction factor is 1.10.

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

-15

0

70

100

150

200

.79

.87

1.00

1.06

1.15

1.25

.81

.88

1.02

1.08

1.17

1.27

.82

.90

1.04

1.10

1.19

1.29

.84

.92

1.06

1.12

1.22

1.32

.85

.93

1.08

1.14

1.24

1.34

.87

.95

1.10

1.16

1.26

1.36

.88

.97

1.12

1.18

1.28

1.39

.90

.99

1.14

1.20

1.31

1.42

Corrected SP is 1.10 X 2.75" SP =

3.025" SP at 70°F and sea level.

To simplify, use 3.00"SP.

Using the Direct Drive Performance

tables, enter the tables at the

required Static Pressure, 3.00" SP.

Reading down the column, find

the CFM rating(s) thatmeet the

required 1000 CFM. Several

blowersmeet this requirement,

one of which is aModel 1400with

a 12-1/4" x 2-7/8"wheel and 6"

inlet. The blower will run at 3450

RPM and require 2.46 BHP at 70°F

and sea level.

Correct the BHP. Divide 2.46 by the

correction factor (1.10). 2.46÷ 1.10=

2.24BHP at 100°F and 1000' altitude.

Using the Belt Drive Performance

tables, one selection for 1000CFM at

3" SPwould also be aModel 1400.

The blower will run at 2470 RPM and

require 1.45 BHP at 70°F and sea

level. (Actual RPM and BHPwas cal-

culated by interpolating between the

1050 and 900 CFM in the tables.)

Correct the BHP. Divide 1.45 by the

correction factor (1.10). 1.45 ÷ 1.10 =

1.32 BHP at 100°F and 1000' altitude.

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