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University of Helsinki Department of Computer Science

Department of Computer Science

Data Center Energy Retrofits

My Ph.D. dissertation titled Data Center Energy Retrofits is available from this page as thesis.pdf. A version that omits the publications will also be available from e-thesis.

The public examination will be held in Auditorium E204 in the Physicum building in Kumpula, Helsinki at 12 o'clock noon on December 12th, 2013. The Facebook event is updated with further details. A Google map is also available.


On p.x the text should read "Figure 2 in Pub. I [...]". Thanks to Markku Kojo for spotting this mistake. It is repeated on p.53, as the same text block is duplicated there.

On p.17 I claim that "HP's Wynyard DC site is located near Dublin, Ireland." while in reality Wynyard is located nearby the town of Billingham in Northeast England.

On p.34 the text should read "CAC alone could yield savings in the order of 0.5 MtCO2e yearly [...]".

On p.36 the installation costs are calculated as "64264 ∗ 469 + 9386 ∗ 2346 = 52180339". The equation is clearly wrong, as I've used more precise intermediate values for the CAC costs in the formula. The end result is right, however. Thanks to Teemu Kerola for spotting this mistake.

The URL in reference [80] is malformed or has since been changed. The PDF for "Chiller-less Facilities: They May Be Closer Than You Think" can be found from this link.

Reprinted Publications

Underfloor Air Containment, IEEE Online Conference on Green Communications, October 29-31th, 2013.

Harvesting Heat in an Urban Greenhouse, ACM CoNEXT 2012 workshop on Urban Networking, Nice, France, December 10th, 2012. (slides)

Implementation and Evaluation of a Wired Data Center Sensor Network, (read the web version) 1st International Workshop on Energy-Efficient Data Centres (E2DC), Madrid, Spain, May 8th, 2012, in connection with e-Energy 2012 (slides)

Cold Air Containment, Proceedings of the 2nd ACM SIGCOMM workshop on Green networking, August 19th, Toronto. (slides)

Running Servers around Zero Degrees, First ACM SIGCOMM Workshop on Green Networking, August 30th New Delhi, India. Republished in ACM's CCR Volume 41, Number 1, January 2011 (slides)

Technical details

Some technical details are described on a separate wiki page.