With the increasing demand for high-density IT equipment, data center cooling systems face a critical need for both high energy efficiency and effective thermal management. This study addresses this challenge by focusing on liquid cooling methods, specifically cold plate and immersion cooling, which offer superior heat transfer and support for higher coolant supply temperatures. We conducted a matrix-based analysis of 15 different system configurations to evaluate their energy performance. Our analysis considered key factors like coolant supply temperature (S-class), coolant properties, and system design. Our findings reveal that the S-class standard, originally for cold plate cooling, can also be applied to immersion cooling systems. We showed that several dielectric fluids performed stably between 40°C and 50°C. As S-class levels rise, conventional chillers are replaced by cooling towers, which cuts system power by up to 75%. Pump energy consumption is heavily influenced by the coolant's density and thermal properties; low-viscosity, high-conductivity fluids significantly reduce energy use. Under a 6 MW IT load, higher S-class configurations achieved a design cooling PUE below 1.04. This research underscores the critical importance of selecting optimal temperature set-points, coolant types, and system architecture from the initial design phase to achieve maximum cooling efficiency.
Cho et al. (Tue,) studied this question.