Performance Analysis of IT-to-Facility Heat Exchangers

This technical report presents an analytical investigation into the performance of IT-to-facility heat exchangers (ITFHX) in the context of two-phase direct-to-chip (2PDTC) cooled AI data centers. The focus is on evaluating how various facility-side fluids, including air, a propylene glycol-water mixture (PG25), and refrigerant R515b, impact the operational efficiency and thermal management of high-performance computing systems. The study utilizes analytical models to assess the performance of different heat exchanger configurations, considering parametric variations in inlet temperatures and heat loads. The findings indicate that the choice of facility coolant plays a crucial role in the thermal performance of the cooling system, highlighting the necessity for integrated design approaches to optimize the efficiency of next-generation AI data center architectures. The report also presents a system-level operational expenditure (OpEx) estimate for various configurations, underscoring the importance of optimizing both IT and facility cooling systems to meet the growing thermal demands posed by advanced computing technologies.