Greenheck 240XP-CUB Manual page 18

Preliminary Selections
At this point we know the model, cfm and Ps. With this
information we can refer to the GB performance charts
to determine the sizes available to move 2400 cfm
against 0.50 in. Ps.
In our case, all of the criteria can be met by more than
one size of a particular model. When this occurs,
choose the size that provides the greatest airflow range
about the desired cfm. For example, many direct drive
fans have three speeds. If possible, choose a size that
uses the middle rpm. This will allow some final system
adjustment if the actual cfm the job requires is
somewhat higher or lower once the fan is installed. Belt
driven fans have adjustable motor pulleys which allow
the fan speed to be varied. With belt drive units, avoid
Stability Considerations
Whenever there is more than one size to choose from,
it is not recommended to select from the performance
box in the far right column for any given rpm unless the
Ps is known to be accurate. For example, the GB-200
selection (see table below) of 2493 cfm at 0.50 in. Ps is
the far right selection at 700 rpm.
MODEL
hp RPM
(rpm RANGE)
GB-141-5
1/2
1360
(1125-1360)
3/4
GB-141 1545
785
GB-161-4
1/4
(634-865)
865
985
GB-161-5
1/2
(852-1100)
1100
770
GB-180-3
1/3
(618-810)
810
900
GB-180-5
1/2
(700-940)
940
1000
GB-180-7
3/4
(764-1055)
1055
1185
1
1335
GB-180 1 1 /
2
1460
2
700
GB-200-5
1/2
(512-770)
770
18
Tip
0.000 0.125
Speed
Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp Sone Bhp
2522 2433
5207
14.6 0.48 14.3 0.50
2866 2787
5915
17.6 0.71 18.0 0.72
2318 2104
3416
8.9 0.18 8.5 0.19
2555 2359
3764
10.6 0.24 10.1 0.25
2909 2737
4287
13.4 0.35 12.7 0.36
3249 3094
4787
15.3 0.48 14.7 0.50
2994 2833
3729
8.1 0.25 9.2 0.26
3150 2997
3923
10.6 0.29 10.3 0.31
3500 3364
4359
12.7 0.40 12.4 0.42
3655 3527
4553
13.6 0.46 13.4 0.47
3888 3768
4843
15.2 0.55 14.7 0.57
4102 3989
5109
16.2 0.65 15.7 0.67
4607 4507
5739
19.0 0.91 18.4 0.94
5191 5102
6465
22.0 1.31 22.0 1.33
5677 5595
7071
26.0 1.71 25.0 1.74
3873 3591
3917
10.3 0.39 9.6 0.40
4260 4013
4308
12.1 0.52 11.0 0.53
selecting near the maximum rpm of a size to allow for
final adjustments if necessary.
There are four GB sizes to choose from in the QD
catalog. These sizes along with their performance data
are in the table below.
Model and Performance Box Data
Size
GB-141
GB-161
GB-180
GB-200
The next box to the right (0.625 in. Ps) is empty
because the performance at that point is unstable. This
means that 2494 cfm at 0.50 in. is marginally stable.
For more information on fan stability, contact
Greenheck.
STATIC PRESSURE / CAPACITY
0.250 0.375 0.500
2346 2258 2166
13.9 0.51 13.5 0.52 13.1 0.52 12.7
2709 2634 2556
17.4 0.74 17.1 0.75 16.8 0.76 15.9
1875 1587
8.3 0.19 7.8 0.19
2162 1932 1624
9.7 0.26 9.4 0.26 8.8 0.25
2567 2382 2176
12.3 0.37 11.9 0.38 11.5 0.38 10.9
2943 2786 2614
14.1 0.52 13.8 0.53 13.5 0.53 13.0
2651 2427 2139
9.1 0.29 8.5 0.30 7.8 0.30
2832 2624 2375
10.0 0.33 9.3 0.35 8.6 0.35
3219 3052 2858
12.1 0.44 11.3 0.46 10.5 0.48 10.2
3388 3234 3052
13.1 0.49 12.3 0.52 11.4 0.54 11.0
3638 3504 3339
13.7 0.58 13.3 0.62 13.0 0.64 12.4
3866 3741 3596
14.9 0.68 14.4 0.72 14.0 0.74 13.5
4400 4290 4179
17.8 0.96 17.4 0.98 17.1 1.03 16.7
5010 4912 4814
21.0 1.36 21.0 1.37 21.0 1.41 20.0
5514 5424 5335
24.0 1.77 24.0 1.79 24.0 1.81 24.0
3307 2973 2493
9.2 0.41 8.6 0.41 7.8 0.40
3744 3477 3140
10.7 0.55 10.2 0.55 9.8 0.55
CFM Sones Bhp
2556 16.8 .76
2614 13.5 .53
2375 8.6 .35
2493 7.8 .40
0.625 0.750 0.875
2062 1942 1792
0.52 12.2 0.53 11.6 0.52 11.0
2475 2384 2286
0.77 14.9 0.77 14.8 0.77 14.7
1914 1550
0.37 10.2 0.35
2428 2197 1899
0.53 12.5 0.52 12.0 0.50
1700
7.4 0.28
2053
8.2 0.34
2624 2347 1821
0.48 9.8 0.47 9.2 0.43
2844 2601 2272
0.55 10.6 0.54 10.1 0.52
3164 2952 2712
0.66 11.9 0.66 11.6 0.65 11.1
3432 3251 3050
0.76 12.9 0.77 12.7 0.77 12.4
4045 3900 3753
1.05 16.2 1.07 15.8 1.10 15.4
4715 4599 4474
1.47 19.9 1.49 19.5 1.51 19.2
5245 5155 5049
1.86 23.0 1.93 23.0 1.95 23.0
2643
9.3 0.52
RPM
1545
1100
810
700
1.000
1602
0.51
2176
0.78
2387
0.63
2811
0.77
3575
1.10
4343
1.54
4938
1.97