Product specifications

21
SELECTION PROCEDURE:
TABLE 5
Elevation above Capacity
Sea Level (ft.) Factor
0 1.00
2000 .99
4000 .98
6000 .97
8000 .96
10000 .95
TABLE 6
Evaporator Fouling Capacity kW
Factor (hr-ft-°F/BTU) Factor Factor
.0001 1.000 1.000
.00025 0.992 0.997
.0005 0.978 0.990
.001 0.951 0.978
TABLE 7
Cooler Curve No. for Table 11
Unit Std Optional Optional
Model CH1 CH2 CH3
Size 44°F(CLR) 42°F (CLR) 40°F (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:
50 Tons at 54°F entering, 44°F leaving chilled water.
Design ambient is 95°F using R22 refrigerant. Minimum
operating ambient is 50°F. Altitude is 6000 feet.
Evaporator fouling is .00025. Electrical characteristics
are 460/3/60. Unit to use 40% ethylene glycol by
weight. (NOT ARI CERTIFIED)
Step 1 - Unit Selection
For 6000 feet elevation, divide the required tonnage
by the altitude correction factor from Table 5.
50
= 51.5 Tons
.97
To c o r r ec t f or e v ap o r a to r f ou l i n g, c o ns u l t Ta bl e 6 . I n
this example, the fouling factor is .00025 which has a
capacity factor of 0.992 and a kW factor of 0.997, so
the capacity correction is as follows:
51.5 Tons
= 51.9 Tons
.992
To c o rr ec t f or 4 0 % E .G ., c o ns ul t Ta bl e 4 a f or a c or re ct io n
factor and make the following adjustment.
51.9
= 53.3 Tons
.973
Entering the tables on page 24, we see that an
ACDSB 055D for water at sea level will do 54.3 tons
drawing 62.4 compressor kW.
The unit will do the following, when corrected for
altitude fouling and ethylene glycol
Capacity 54.3 x .992 x .973 x .97 = 50.8 Tons
which exceeds the original requirement.
Compressor kW needs to be adjusted from Table 4a by
factor K1 and Table 6 for 0.00025 fouling as follows:
62.4 kW x .991 x .997 = 61.7 kW
Step 2 - Cooler GPM and Pressure Drop
Water GPM = Tons (water) x 24 = 50 x 24 = 120 GPM
Cooling Range 10
Correcting flow rate for glycol from Table 4a:
GPM = 120 x 1.116 = 133.92 (E.G.) GPM
Referring to pressure drop curve #9 (Figure 13) on page
23 for the evaporator pressure drop, we see a 8.8 feet
of water pressure drop for 120 GPM of water.
Correcting pressure drop for glycol from Table 4a:
P. D . ( E G ) = 8 . 8 f t . o f w a t e r x 1 . 3 3 1 = 1 1 . 7 f t . o f w a t e r
PSI = Feet of water x .433 = 5.07
ENGLISH I.P. UNITS 60 HZ