Airedale EasiCool 6kW 64kW - Manual (Page 51)

EasiCool™ Precision Air Conditioning
51 EasiCool Technical Manual 7525389 V1.1.0_02_2013
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Ethylene Glycol Correction Factors - WX Models
For conditions outside those quoted, please refer to Airedale.
The Use of Glycol
Glycol is recommended when a supply water temperature of +5°C or below is required or when static water can be
exposed to freezing temperatures.
The presence of glycol in the system has a direct effect upon the Cooling Duty, the Design Flow Rate and the unit
Pressure Drop.
To approximate the effect of glycol on unit performance, the following correction factors when applied can be used as a
guide.
Where:
V = Corrected Flow Rate
THR = Equivalent Total Heat of Rejection (THR) (kW), refer to Cooling Duties - WX Models , (the change in THR values
as glycol concentration is increased is negligible.)
∆
T = Temperature difference between Water/Glycol Inlet/Outlet (°C).
∆ P = Maximum Water/ Glycol Pressure Drop for the indoor unit (kPa).
∆ Pw = Equivalent Water Pressure Drop for indoor unit (kPa), use the corrected flow rate V . Refer to Waterside
Pressure Drop (kPa) - WX Models .
Ethylene Glycol (Volume) / Freezing Point °C
10% / -4°C 20% / -9°C 30% / -15°C 40% / -23°C
V
Corrected Flow Rate = THR / ∆T Flow Rate
x by
0.240 0.250 0.250 0.260
∆ P Corrected Pressure Drop = ∆Pw Pressure Drop 1.041 1.083 1.133 1.200
Example: V26WX2-EZ Condensing Entering / Leaving at 30°C/35°C, Based on ΔT of 5°C,
24°C/45% RH Ambient, 20% Ethylene Glycol
Ethylene Glycol (Volume) / Freezing Point °C
10% / -4°C 20% / -9°C 30% / -15°C 40% / -23°C
V
1.76 l/s =
THR (35.2) / ∆T
(12 - 7 = 5∆T) =
7.04
x by
0.240 0.250 0.250 0.260
∆ P 157Pa = ∆ Pw 145 kPa 1.041 1.083 1.133 1.200