Google is preparing to open its newest data center, a large facility in a former paper mill in Hamina, Finland. The facility uses the sea to replace the chiller in its cooling system, collecting cool water from an inlet pipe located about 7.5 meters beneath the service of the Baltic Sea. The water than travels into the facility through large tunnels carved out of granite. Google also used a small submarine to explore the tunnels to ensure that they were clear of blockages that could impede the flow of water. The incoming water goes through a series of four straining systems, and then into a water-to-water heat exchanger, where it cools a separate water loop that is used to cool the data center. In this video, Google Senior Director of Data Center Construction Joe Kava discusses the Hamina facility and the sea water cooling system. This video runs about 2 minutes, 30 seconds.
Speaking at Tuesday's European Data Center Summit in Zurich, Kava said Google had to conduct extensive thermal testing before deciding whether to use the cooling system, which was developed by the paper company Stora Enso before it closed its plant in 2008. The thermal testing tracked differences in ocean temperature in different tidal and weather conditions, which helped the company determine the best depth for the input to provide an optimal temperature.
Google also is taking steps to re-cool the water before it is returned to the sea to ensure that its operations do not have an adverse environmental impact on the sea.