Ambient air alone cools large data centre
A data centre without mechanical cooling has been achieved by consultants Norman Disney Young for EDS, an HP company. This data centre in the north east of England provides 8100 m2 of technical space and achieves a Tier 3+ rating on the standard of The Uptime Institute Tier Rating. The design strategy was to use outside air to directly cool IT equipment in the data halls, rather than chillers and chilled water, and won the category for technical innovation of the year.
NDY carried out an extensive analysis of historical weather data for the area, which showed the local climate to be very conducive to a direct cooling solution to meet industry standard conditions. The design approach can be scaled down to smaller data centres where environmental conditions permit the use of fresh-air cooling.
The SMC4 data centre involved the fit-out of a new-build warehouse for use as an exemplar data centre.
The design used eight 2.1 m-diameter variable-speed axial fans to supply outside air to each hall. Another eight fans are used for exhaust air from each hall, in an N+2 arrangement in each of eight data halls.
Return air is mixed with outside air to avoid overcooling of supply air to the 5 m-deep plenum below the computer equipment.
Single bank filters remove contaminants, and humidity control is provided by low-energy spray humidifiers and supplementary cooling coils.
This approach to cooling the SMC4 data centre is expected to achieve 40% energy savings compared to a typical modern design for a data centre — worth over £2 million a year for this project.
The calculated PUE (power usage effectiveness) is 1.16, which means over 85% of the power drawn by the site reaches the IT equipment. Legacy data centres typically have PUEs of 1.8 (56% of power reaching IT equipment) to 3 (33%).
Another economic benefit is the provision of 1360 m2 of fee-earning technical space for the original power provision.
