Ultra-Low GWP Refrigerants to Reduce Carbon Footprint in Data Centers

The scope of the project will first include fundamental heat transfer lab evaluation of the new developmental fluids as well as the legacy fluids under different operating and surface conditions. Second, performance application type lab evaluations of new and existing fluids will be carried out in a commercially available two-phase immersion tank with servers under different ambient conditions – to simulate different climate zones. The fluids will be compared within the same immersion tank. In addition, the immersion tank performance will be compared with an actual air-cooled system either based on catalog or actual lab measurement data. Monitoring of fluid health/quality, by fluid sampling and analysis, hardware conditions and failure, fluid losses and vapors concentration around the equipment will also be part of the scope. The second phase is intended to be a real proof-of-concept of the new ultra-low GWP developmental fluid(s). In the last part of the project, the team intends to design and model – using platforms such as EnergyPlus – an entire data center to estimate its energy and water consumption, as well as its life cycle climate performance (LCCP) both using two-phase immersion and air cooling. The model will be calibrated by using performance data obtained during the testing phase. The simulations would be carried out for different climate zones in the U.S. The modeling exercise could also be extended to consider heat recovery systems that would further reduce the carbon footprint of data centers. The laboratory evaluations will be performed at Oak Ridge National Laboratory (contractor) using fully instrumented systems, allowing the detailed measurement of heat transfer properties.