Tropical data centre proof-of-concept

• Main Authors: Le, Duc Van, Liu, Yingbo, Wang, Rongrong, Tan, Rui
• Other Authors: Tan Rui
• Format: Conference or Workshop Item
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Computer science and engineering::Hardware::Performance and reliability; Data Center; Temperature
• Online Access: https://hdl.handle.net/10356/137780
• Institution: Nanyang Technological University

Singapore is a data center (DC) hub in Southeast Asia. However, Singapore's year-round high temperatures and humidity levels introduce significant challenges for the local DC operators in improving the energy efficiency of their infrastructures. As Singapore's DCs spend more energy in cooling, their average power usage effectiveness (PUE), which is 2.07, is higher than the global average of 1.7. In the United States, the DC sector accounted for 1.8% of the country's total electricity consumption in 2014. In Singapore, this percentage is up to 7%. Thus, technologies that can improve DC energy efficiency in the tropics will further enhance Singapore's attractiveness as a regional data center hub. They are also important to Singapore's energy sustainability and commitment to Paris Agreement. Air-side free cooling that utilizes outside cold air to cool the information technology (IT) equipment has been increasingly used to improve the energy efficiency of DCs. However, air-side free cooling in the tropics has been long thought infeasible from the intuition that the high temperature and relative humidity (RH) of the air supplied to the servers will undermine their performance and reliability. On the other hand, the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) has been working for years on expanding its suggested allowable temperature and RH ranges for IT equipment. For instance, the servers compliant with ASHRAE's Class A3 can operate continuously and reliably when the temperature and RH of the supply air are up to 40 degree Celsius and 90%. This sheds light on the possibility of air-side free-cooled DCs in Singapore, since the record temperature in Singapore is 37 degree Celsius only and the ambient RH is in general lower than 90%. To investigate the feasibility of air-side free cooling in Singapore, together with multiple partners in DC industry and research, we designed, constructed, and experimented with an air-side free-cooled DC testbed consisting of three server rooms located in two local DC operators' premises. The testbed hosts 12 server racks with 60kW total power rating. This technical report holistically introduces this project, presents the measurement results, discusses the experiences and learned lessons obtained from the project.