This blog will detail the experimental cooling construction set up on the 4th floor terrace of the Exactum building. The purpose of the so called Helsinki Chamber (HC) is to provide a low-cost cooling setup that avoids conventional air conditioning used by server rooms and small data centers.
Early name ideas for the HC were “[bee]hive” and “birdhouse”. The name Helsinki chamber mimics the semantics of Kyoto wheels, a complementary or alternative technique aimed for mostly the same purpose. The key differences are that Helsinki Chambers are fully placed outdoors, intake air is not isolated, and the hardware is distributed among multiple HCs.
The initial phases #1 and #2 took place earlier in 2010. Phase #1 consisted of a single computer spending a full weekend outdoors sandwiched between two hard plastic boxes. During the weekend of Feb. 12th to 14th, ambient temperatures dropped to -21 C. As the prototype survived the test, phase #2 began operation on Feb. 19th and continued until October 11th.
For phase #2, a standard tube tent was erected on the roof terrace of the Exactum building. The purpose of the tent was to shield the computer equipment from direct rain and snowfall. Simultaneously, our intent was to maximize air flow through the tent. Phase #2 was a partial sucecss, as the tent turned out to be surprisingly efficient in retaining heat. After multiple customizations, we managed to get the internal to ambient temperature delta to stabilize roughly around +5 C .
During phase #3, we have constructed a much sturdier case around a standard 19″ 26U rack. Cold supply air is isolated from warm exhaust air, and the idea is to maximize air flow through the installed hardware. Some effort has been put into the visual side, as the HC setup includes see-through plexiglass windows on the front and back sides. Construction pictures are available: https://picasaweb.google.com/114818302608767208085/HCConstruction
The following posts will detail phases #1 and #2, and from there onwards we will describe phase #3 as it proceeds. For impatient readers, our article presented at the First ACM SIGCOMM Workshop on Green Networking contains most of the details of the first two phases.