YLAA - HVAC Tech Support

FORM 150.62-EG5 (108)
5. Calculate GPM:
90 Tons x 24
GPM = 216 GPM
10°F Range
6. From Page 10, read 10 ft of water cooler pressure
drop for GPM:
7. A YLAA0090 is suitable.
EXAMPLE – Brine Chilling
1. GIVEN: Provide a capacity of 80 tons cooling
30% by weight Ethylene Glycol from 50°F to 40°F,
0.00025FF, 95°F air on the condenser, 60 Hz and
4000 altitude.
2. DETERMINE:
Unit Size kW Input
Ethylene Glycol GPM Cooler Pressure Drop
3. See Ethylene Glycol correction factors, for 30%
by weight Ethylene Glycol.
READ: .974 Tons factor
.995 Compr. kW factor 26.1 Gal./°F/Tons factor
4. See Performance Data Correction Factors for
0.00025 fouling factor and 4000 ft. altitude.
READ: .983 Tons factor 1.021 kW factor
5. From RATINGS on pages 18 - 23:
SELECT: YLAA0090 (English Units)
91.4 Tons 82.0 Compressor kW
6. Determine YLAA0090 brine cooling capacity
and Compressor kW requirement:
A. Tons = 91.4 x .974 x .983 = 87.51
B. Compr. kW = 82.0 x .995 x 1.021 = 83.3
Determine average full load Compressor kW at
80 tons: (80/87.51) x 83.3 = 76.15kW
8. Determine Ethylene Glycol GPM:
Tons x Gal. °F/min/Ton factor
GPM = Range 80.0 x 26.1
GPM = 10 GPM = 208.8
9. Determine Cooler Pressure Drop:
A. See Ethylene Glycol correction factors for 30%
by weight Ethylene Glycol.
READ: 1.096 Pressure Drop Factor
B. See pages 18-19 at 88.7 GPM for the YLAA0090.
READ: 6.8 Ft. H 2
O Pressure Drop
C. Cooler Pressure Drop = 6.8 x 1.096 or 7.5 Ft.
H 2
O
10. YLAA0090 is suitable.
jOHNSON CONTROLS
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