Airedale DeltaChill FreeCool 110kW - 1080kW - Manual (Page 8)

DELTACHILL
™
Chillers
8
Chillers
Installation, Commissioning and Maintenance Manual : 7025232 12 / 2013
Design Features & Information
Specific Heat Capacity (SHC)
% Ethylene Glycol Concentration 0% 10% 20% 30% 40%
Specific Heat Capacity (kJ/kgK) (1) 4.190 4.115 3.901 3.686 3.474
% Propylene Glycol Concentration 0% 10% 20% 30% 40%
Specific Heat Capacity (kJ/kgK) (1) 4.190 4.139 4.033 3.903 3.749
(1) Data quoted for water/glycol solutions at a nominal temperature of 10°C.
CAUTION Only use the SHC data when calculating fluid VOLUME. Use figure for 0% concentration
(100% water) when applying Glycol Correction Factors, refer to
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Minimum System Water Volume Calculations
METHOD 1
(Preferred Method) Where the system permanent heat load is known, the minimum water volume in litres V
min
is:
V
min
= Water Flow Rate (litres/minute) x Minimum Compressor Run
Time (mins) x Chiller Loading Factor
Where V
min
is the minimum water volume in litres
Minimum Compressor Run Time is 2 minutes
Chiller Loading Factor = Minimum Turndown (kW) x 1.2
Permanent Heat Load
Example: Chiller at 35°C Ambient, 7/12°C Water, Model DCC033DR-08BMM0 with a
permanent load of 129.6kW
Unit capacity at design conditions = 326 kW
Permanent Heat Load = 129.6kW
Minimum Turndown = 27%
V
min =
326 x 60
x 2 x
(326 x 0.27)
x 1.2 = 1522 Litres
4.19 x 5 129.6
METHOD 2 Where the system permanent heat load is unknown:
V
min
= Water Flow Rate (litres/hour) x Minimum Turndown Ratio x
1.2

Maximum number of compressor starts (per hour)
Example: Chiller at 35°C Ambient, 7/12°C Water, Model DCC033DR-08BMM0
Unit capacity at design conditions = 326 kW
Minimum Turndown = 27% (0.27)
V
min =
326 x 3600
x 0.27 x 1.2 = 1512.5 Litres
4.19 x 5
12