The cool factor

Peter Newburn | 19 Nov 2015 | Comments

The ‘cool’ factor: using lakes to cool data centres

Traditionally, data centres are cooled using mechanical air cooled chillers, which provide chilled water to the computer suite cooling units. Rising energy costs and corporate policies to reduce energy consumption have meant many companies are on the lookout for innovative new ways to cool their data centres. One way we’ve identified to do this is by using water sources like lakes that are adjacent to data centre sites as a potential ‘heat sink’.

We recently conducted a study into the feasibility of reducing the load on the mechanical chillers in a data centre by rejecting heat into nearby lakes. The study looked into several areas including the baseline environmental conditions of the lake to understand the impact on wildlife and the environment, and the options for cooling systems within the lake, including the potential cost and energy savings for each option.

The study brought together experts from Atkins’ Design and Engineering and Water and Environment teams, combining expertise from our data centre design specialists with the ability to accurately model the lake water.

Two tools helped determine if the lake could be used for direct cooling – the Aquatic Heat Model (AqHM), an Atkins-designed tool for long term temperature rise modelling, and Mike 3D, a standard software for environmental studies that provides spatial modelling of temperature and salinity. These tools provided good three dimensional hydrodynamic models of the lake, accurately predicting the effects on the lake’s temperature, nutrients, metals and dissolved oxygen if it were to absorb heat from the data centre.

Options were also provided for the mechanical and electrical design to integrate the lake cooling system into the existing data centre infrastructure without interrupting it or compromising its resilience. The main consideration is to reject heat through either a closed or an open loop pipework system, exchanging heat with the data centre’s chilled water system. The position of the lake pipework is crucial to the modelling, as its position determined the best potential for heat rejection.

Ultimately a solution like this will take advantage of a water source’s ambient temperature, without compromising the environment around it. Most importantly, it could provide huge energy savings and great ROI in the long term.

Data centre lake