Investigation of the Mechanism of Temperature Rise in a Data Center With Cold Aisle Containment

Abstract

This paper theoretically investigates the relationships among factors that affect the temperature rise of server racks and experimentally tests the influence of variable space contained arrangements on the thermal performance. To express the flow and heat transfer process of cold air in servers and analyze the critical factors affecting the temperature rise, a simplified mathematical model representing servers is developed using experimental results. An experiment is conducted within a modular data center in which cold air is supplied from a raised floor. The experiment employed a variable space of cold aisle containment and measured the resulting temperature rise, as well as pressure difference of racks and other parameters, in the simplified mathematical model. By comparing the experimental results and theoretical calculation, the theoretical model is proved to be reasonable and valid. The model predicts that the critical factors affecting the temperature rise of racks consist of static and dynamic pressure difference, total pressure of the fans, geometric structure, power consumption, resistance of doors, and opening area of servers. The result shows that the factor affected by the cold aisle contained system is the static pressure, while for the dynamic pressure difference, the contained architecture has a slight positive effect. Although the average temperature rise is quite decreased in the contained system, the static pressure distribution is nonuniform. A half-contained system which reduced contained space ratio to 50% is measured to cause a 22% increase of the static pressure difference, making a more uniform temperature distribution.