Data-centre cooling saves energy and creates revenue
SemperTec’s Delta-T cooling solution for data centres is based on installing cooling units in the rows of racks, rather than CRAC (computer-room air-conditioning) units around the perimeter. By localising cooling in this way, the number of IT racks in a room can be increased by 16%. An example put forward by SemperTec is 352 racks being increased to 408, with the potential revenue from those 56 extra racks being over £1 million a year. And there’s an electricity cost saving of over £77 000 a year compared with CRAC units.
Delta-T units protrude slightly forward from the server racks (see photo). Centrifugal fans deliver cool air sideways along the front of the server racks. This cooled air is drawn through the server racks and discharged at the rear.
A significant improvement to overall operating efficiency can be achieved by letting the hot air return to the cooling unit through the server racks themselves via interconnecting grilles to create a 300 mm-deep air plenum.
Discharging cooled air direct into the space obviates the need for a large floor void and grilles to let air up into the cold aisles. Fan energy is significantly reduced, by around 15%.
The cooling energy can be from chilled water or DX using R407C. To avoid condensation, the evaporating temperature is 13°C.
Delta-T units can be installed as a data centre is populated.