D
O
N
O
T
S
E
L
E
C
T
T
O
T
H
E
L
E
F
T
O
F
T
H
I
S
S
Y
S
T
E
M
C
U
R
V
E
Static Pressure (in. wg)
Static Pressure (Pa)
Volume (cfm)
3
Volume (m/hr )
RPM (Belt)
RPM (Direct)
RPM (Vari-Green)
HP
Density 0.075 lb/ft
3
Density 1.2 kg/m
3
2200
Motor HP
Fan
RPM
Static Pressure in Inches wg
Belt Direct .5 .75 1 1.25 1.5 1.75 2 2.25 2.5 2.75
141HP
143HP
1/4
VG -Vari-Green is a direct drive brushless DC motor.
1020
CFM
488
BHP
0.08
Sones
6.3
B-1/4 1140
CFM
645 413
BHP
0.11 0.11
Sones
7.7 7.6
1320
CFM
837 700 486
BHP
0.17 0.18 0.17
Sones
10.3 9.8 9.9
1500
CFM
1009 903 774 592
BHP
0.24 0.26 0.26 0.25
Sones
13.1 12.3 12.2 12.4
1/3 1655
CFM
1151 1064 959 833 668
BHP
0.32 0.34 0.35 0.35 0.34
Sones
15.0 14.1 13.3 13.1 13.6
1/2
A-1/2 1725
CFM
1213 1132 1035 932 784 588
BHP
0.36 0.38 0.39 0.39 0.39 0.37
Sones
16.2 15.4 14.7 14.2 14.3 14.9
1812
CFM
1289 1213 1127 1030 911 763 545
BHP
0.41 0.43 0.45 0.46 0.45 0.45 0.41
Sones
17.8 17.2 16.6 15.8 15.6 15.9 16.6
1900
CFM
1366 1294 1218 1127 1033 901 753
BHP
0.47 0.49 0.51 0.53 0.53 0.52 0.51
Sones
19.0 18.4 18.0 17.4 16.8 16.7 17.0
3/4
2050
CFM
1495 1430 1361 1285 1200 1113 991 857 672
BHP
0.58 0.61 0.63 0.65 0.66 0.66 0.66 0.65 0.61
Sones
21.0 20.0 19.8 19.3 18.8 18.6 18.3 18.3 18.6
2170
CFM
1598 1536 1472 1407 1328 1248 1163 1045 919 757
BHP
0.68 0.71 0.73 0.76 0.77 0.78 0.79 0.78 0.77 0.74
Sones
22.0 22.0 21.0 21.0 21.0 21.0 21.0 20.0 19.7 19.8
2200
CFM
1623 1562 1500 1436 1360 1281 1200 1088 968 834
BHP
0.71 0.74 0.76 0.78 0.80 0.82 0.82 0.81 0.80 0.79
23.0 22.0 22.0 22.0 21.0 21.0 21.0 21.0 20.0 20.0
26
Roof Downblast - Belt Drive
Size- : GB • H-GB
Performance certified is for installation type A: Free inlet, Free outlet. Power rating (BHP) does not include transmission losses. Performance ratings include the effects
of a birdscreen. The sound ratings shown are loudness values in hemispherical sones at 5 ft. (1.5 m) in a hemispherical free field calculated per AMCA Standard 301.
Values shown are for installation type A: free inlet hemispherical sone levels.
Roof Downblast - Exhaust
Belt & Direct Drive
GB-141HP • G-143HP
Damper Size = 16 x 16
Roof Opening = 18 x 18 (470 x 470)
Shroud Thickness = 0.051 (1.3)
Motor Cover Thickness = 0.040 (1.0)
Curb Cap Thickness = 0.064 (1.6)
^Approximate Unit Weight G/GB = 75/83 lbs. (34/38 kg)
All dimensions in inches (millimeters). *May be greater depending on
motor. ^Weight shown is largest cataloged Open Drip-Proof motor.
MAXIMUM BHP AT A GIVEN RPM = (RPM/2351)
3
MAXIMUM RPM - GB-141HP=2200, G-143HP=2200
TIP SPEED (ft/min) = RPM x 3.829
MAXIMUM MOTOR FRAME SIZE = 145T
1
3
⁄4 (44)
4 (102)
*23
3
⁄4
(603)
22
(559)
28
3
⁄8
(721)
B-1140-RPM A-1725-RPM VG-2200-RPM
VG-
3/4
Direct Drive RPM
