Unit testing on 02.04.19 by DNB
Using 8 No Heatbanks a 90kW room design load was introduced.
Each of the 3 No DMF065D units run in freecooling mode with no DX.
The outside ambient was 9.8°C.
The input power to each unit was 2.5kW with a total of 7.5kW input for 3 units.
EER = 90 / 7.5 EER = 12.00
PUE = 90 + 7.5 + 3.6 (UPS losses at 4%) PUE = 1.12 Cooling PUE = 1.08
90
Existing D63 Combicool units running on CW as the primary.
Chiller COP estimated @ 3.0
D63 units running @ 6.0kW fan gain each.
Running 3 units at a 90kW load
Chiller load 30kW
3 x D63 fan gain 18kW
Total input power 48kW
EER = 90 / 48 EER = 1.875
PUE = 90 + 48 + 3.6 (UPS losses at 4%) PUE = 1.57 Cooling PUE 1.53
90
At this point in time the saving over the existing system for a 90kW load would be
48kW – 7.5kW = 40.5kW.
Annual saving = 40.5kW x 8760 hrs x £0.12kW/hr = £42,574.
ROI 1 Year 6 Months
Unit 3 was switched off.
The remaining 2 No DMF065D units then run in freecooling mode & partial DX mode.
The outside ambient was now 10.8°C.
The input power to each unit was 7.1kW with a total of 14.2kW input.
EER = 90 / 14.2 EER = 6.34
PUE = 90 + 14.2 + 3.6 (UPS losses at 4%) PUE = 1.20 Cooling PUE = 1.16
90