Product specifications

22
SELECTION PROCEDURE:
TABLE 8
Elevation above Capacity
Sea Level (M) Factor
0 1.00
600 .99
1200 .98
1800 .97
2400 .96
3000 .95
TABLE 9
Evaporator Fouling Capacity kW
Factor (hr-m
2
-°C/kW
-1
)Factor Factor
0.018 1.000 1.000
0.044 0.992 0.997
0.088 0.978 0.990
0.176 0.951 0.978
TABLE 10
Cooler Curve No. for Table 12
Unit Std Optional Optional
Model CH1 CH2 CH3
Size 6.7°C (CLR) 5.5°C (CLR) 4.5°C (CLR)
015S 1 1 1
020S 1 1 2
025S 3 3 2
027S 3 3 4
030S 4 4 4
025D 3 4 4
030D 3 4 6
035D 5 7 8
040D 5 7 9
045D 7 7 8
050D 9 9 12
055D 9 9 12
057D 9 9 12
060D 12 12 12
065D 11 11 11
070D 11 11 11
080D 11 11 11
090D 12 12 12
100D 13 13 13
EXAMPLE
Select an air cooled packaged chiller for the following
conditions of service:
175 kWo at 12.5°C entering, 6.5°C leaving chilled water.
Design ambient is 35°C. Minimum operating ambient
is 10°C. Altitude is 1800 meters. Evaporator fouling is
.044. Electrical characteristics are 460/3/60. Unit to
use 40% ethylene glycol by weight. (NOT ARI CERTIFIED)
Step 1 - Unit Selection
For 1800 meters elevation, divide the required capacity
by the altitude correction factor from Table 8.
175
= 180.4 kWo
.97
To c o r r e c t f o r ev a p o r a t o r f o u l ing, c o n s u l t Ta b l e 9. In
this example, the fouling factor is .044 which has a
capacity factor of 0.992 and a kW factor of 0.997, so
the capacity correction is as follows:
180.4 kWo
= 181.8 kWo
.992
To cor r ect fo r 4 0 % E . G. , c o n sul t Ta b le 4a for a cor r ect i on
factor and make the following adjustment.
181.8
= 186.8 kWo
.973
Entering the tables on page 26, we see that an
ACDSB 055D for water at sea level will do 189.1 kWo
drawing 62.2 compressor kW.
The unit will do the following, when corrected for
altitude and ethylene glycol
Capacity 189.1 x .992 x .973 x .99 =180.7 kWo
which exceeds the original requirement.
Compressor kW needs to be adjusted from Table 4a by
factor K1 and Table 9 for 0.044 fouling as follows:
62.2 kW x .991 x .997 = 61.5 kW
Step 2 - Cooler Flow Rate and Pressure Drop
Water Flow Rate = kWo(water) = 175 kWo = 6.97 Lit./sec.
4.187 x Range 4.187 x 6
Correcting flow rate for glycol from Table 4a:
Flow Rate = 6.97 x 1.116 = 7.78 (E.G.) Liters/sec.
Referring to pressure drop curve #9 (Figure 13) on
page 23 for the evaporator pressure drop, we see a
22.5 kPa pressure drop for 6.97 Liters/sec. of water.
Correcting pressure drop for glycol from Table 4a:
P. D . ( E G ) = 2 2 . 5 k P a x 1 . 3 3 1 = 2 9 . 9 5 k Pa
S.I. UNITS 60 HZ