As part of a customised, scalable and fully redundant cooling solution, Airedale has helped colocation provider UK Grid to reduce the PUE1 at its owned and operated, new ‘carrier-neutral’ data centre, Synergy House in Manchester.

Synergy House offers two floors of tier II data centre space with fully redundant power, cooling and connectivity. The IT equipment converts almost all the power supplied to it into heat, yet to work reliably this heat needs cooling, using yet more power. Precise, efficient control of temperature and humidity is essential for the 24/7 operation of the data centre.

Airedale has worked closely with UK Grid to develop a split system precision air conditioning solution tailored to UK Grid’s requirements and featuring a specially-designed controls scheme that significantly reduce energy usage.

Eight EasiCool 45kW DX downflow units provide redundant under-floor cooling at a constant cold aisle temperature of 22°C and 50% humidity. Hot and cold aisles provide maximum efficiency, delivering conditioned air through the floor-mounted grilles, to the front of the racks within the contained cold aisles. Hot air is discharged from the back of the servers, to be returned via the hot aisles, to the EasiCool units.

Inverters installed on the evaporator fans of the EasiCool units allow the fans to speed up or modulate back in response to changes in temperature. Previously the fans were operating at 100% irrespective of cooling load and were wasting power. An electronic expansion valve fitted to the EasiCool typically provides an increase in the system energy efficiency ratio of up to 30%.

Says UK Grid managing director, Rob Garbutt: “Initially we just had straightforward units with fixed air volume fans giving us a PUE of 1.7. By working with Airedale and introducing cold aisles and the fan inverter drives, we have reduced the PUE to 1.4. The next stage is to introduce Airedale free-cooling equipment which should see this PUE reduce to 1.2.”

Smart controls also facilitate an N+1 precision air conditioning system enabling the EasiCool units to operate on run and stand-by, thereby providing critical redundancy.

“Without doubt we have been working with the best supplier. Airedale has a market history of delivering reliable under floor cooling solutions for data centres and thus was a natural choice for Synergy House,” adds Rob.

The EasiCool units are integrated into the UK Grid SNMP  server via pCOWeb supervisory plug-in cards based on Ethernet TCP/IP secure technology.

“By simply plugging Airedale’s pCOWeb cards into the UK Grid SNMP server, it gives us remote monitoring of parameters specific to the EasiCool units including room temperatures, humidity, status alarms and setpoints, which can be displayed and modified on or off site,” explains Rob.

“It has been a team effort between UK Grid and Airedale. Our approach has been to seek an environmentally-friendly solution. Success has been down to the cooling solution and the tweaking by Airedale to push energy usage down. The benefit of working with Airedale is that they are flexible; they take comments away and find a solution enabling us to react to the market.”

The compact footprint and modular design of the EasiCool allows optimum positioning. Additional units have been designed in and added on as cooling load has increased and UK Grid has grown the facility.

1 PUE (Power Usage Effectiveness) as developed by the Green Grid™

Contact details

electrical industry news, e-lec.org