But it’s not. Northern Sweden has an average annual temperature of 1°C. However, it can be down to -40°C in the coldest winter and, when we are lucky, in the summers it can reach up to 27°C. So a huge range of ambient temperatures has to be accommodated. When the temperature goes below 0°C humidity also more or less vanishes. This requires a cooling system that can handle this range. It will be cold, it will be hot, it will be dry and it will be wet. So, it’s not so “free” cooling as it sounds.
Solving this challenge in the most efficient way possible has made it viable for Hydro66 clients to take advantage of the cheapest power in the EU at scale. This is vital for HPC (High Performance Compute) such as AI, IoT and Blockchain infrastructure where the cost of power is the majority of the total operating cost. This make it possible for us to offer data center capacity without charging a cooling (PUE) overhead - “free cooling is something our clients take very literally!
Hydro66 partner EcoCooling has been leading the march towards direct “free cooling” using adiabatic cooling as a lower cost alternative to refrigeration cooling. This system works best in climates where it’s not constantly hot or humid. Alan Beresford, EcoCooling CTO, spent the last two years designing cooling solutions for our region.
In a recent article in DCR Beresford talks about a “bible” created for data center environment produced by ASHRAE – the American Society of Heating Refrigeration and Air Conditioning Engineers. In essence, ASHRAE has done all the hard work in understanding temperature, humidity, and IT equipment reliability. However, their standards don’t fully allow for sub-Arctic regional conditions.
Using this “bible” EcoCooling have managed algorithms balancing what they call “The x-factor” (calculated IT failure rate variation with operating temperature) which in some cases means that server reliability can be 24% better than in many refrigeration-cooled data centers. This can result in operational annual savings in a 1 MW data center in London of €85,000 in London and €285,000 in Boden, per year, again compared to the traditional refrigeration approach. EcoCooling and Hydro66 jointly developed a unique solution in solving the dry air in the winter months, simply by using their existing evaporate coolers instead of adding humidifiers. Another energy and cost saving solution.
The final product from this program resulted in Cloudcooler, a plug-in ventilation cooling unit. It allows for a very rapid installation without any plumbing requirements - only electricity and network connections. Hydro66 has first-hand experience that it works in the Nordic climate, with 2 MW installed with 100% in-service compliance on temperature. We are soon to roll out another 10 MW in early 2018. We think that this solution, quick roll-out, ventilation-only cooling is the way forward and incontrovertible for the future of Nordic data center requirements. In some way the closest to “free cooling” we can get.