scope:

Recapture of the waste heat from data centers remains a difficulty undertaking. For liquid-cooled data centers, the temperature of the water has been too low to make it economically feasible to put full-blown heat recovery systems in place. The University of Tromso (UiT), in collaboration with an IT manufacturer, has undertaken a detailed study to investigate the technical and economic feasibility of capturing the waste heat from its current data center. A single rack of servers has been converted to liquid-cooling (CPUs only). The rack was tested using inlet water temperatures that satisfy ASHRAE W2 - W5 liquid-cooling classes. Under all inlet water temperatures investigated, the key IT device temperatures remained well within specification, while producing rack exhaust water temperatures as high as 147.2 degrees F (64 degrees C). Using the current UiT cost of energy, and assuming that 50% of the waste heat from a 1 MW data center is reused, there is the potential to save over 375,000 Euros annually. As UiT is building out a new 2 MW data center, the potential for greater heat recapture can greatly expand the re-use of the data center waste heat to the broader campus.