TCO Modeling for Immersion: Unlocking Cost Savings and Efficiency in Data Centers

Author: Allison Bowen, Alitex Data Center Design Services; Eddie Reidman, Intel Collection: 2023 Global Summit - Cooling Environments

Summary

This presentation introduces the OCP Immersion TCO Workstream and its in-development Excel-based TCO modeling tool, targeting Rev 1.0 release by end of Q4 2023. The workstream was launched in late January 2023 and is producing the first vendor-agnostic, community-built open TCO model for immersion cooling. The fundamental driver: the most common adoption objection to immersion cooling is "tanks and fluid are more expensive overall" — and the industry needed a credible, transparent, multi-contributor model to address this.

The model's design premise is comparing equivalent IT digital capacity (IT power stripped of fan and power supply overhead) between an air-cooled facility and an immersion-cooled facility. The tool is built in Excel with full transparency of all assumptions, pre-populated defaults from domain experts, and user-overridable parameters across three levels of expertise (beginner: 3 variables; intermediate; expert: variables tab with 20+ parameters). Outputs include CAPEX/OPEX/TCO comparisons, floor space analysis, energy KPIs (PUE, DUE, ERF), and cooling/power infrastructure breakdowns.

Model outputs from an example scenario show immersion CAPEX at €5.01/W vs air €6.05/W (17% reduction), OPEX 9–12% lower, total TCO 13–18% lower. Floor space total decreases from 5068 m² to 4776–4062 m². Cooling/power ratio drops from 7.72% (air) to 4.07% (immersion). PUE: air 1.20 vs immersion 1.16. The TCO basis: CAPEX savings of at least 30% on infrastructure (eliminating CRAC units, chillers, air handlers, UPS/switchgear downsizing) and OPEX savings up to 33% from removing server fans and chilled water systems.

Rev 2.0 planned additions include: cold plate TCO, Brownfield retrofit modeling, broader climate options, pre-populated energy cost data for US/Canada/Western Europe, and modeling of power reduction from lower Tjunction/reduced leakage in liquid-cooled silicon.