Energy-Efficient Data Center Cooling System
Starting in the ESIF HPC data center (1), IT equipment produces heat as a byproduct. The target is for 90% or more of the heat produced to be acquired via a liquid cooling approach. Learn more about how—and why—we use warm-water liquid cooling in our data center.
Most liquid cooling approaches involve a cooling distribution unit or CDU (2), which interfaces with the facility cooling loop and provides cooling liquid at the appropriate temperature, pressure, and chemistry for the IT equipment. The ten CDUs that cool the Peregrine HPC system are depicted on the dashboard.
For equipment that is not liquid cooled, IT equipment heat is dissipated to air, where it travels through the ceiling plenum (3) and is cooled by a set of fan walls (4), which are analogous to a computer room air handler (CRAH) in a typical data center. The dashboard provides detailed information about the input and output water and air temperatures and flow through the fan walls.
All heat energy from the IT equipment is captured to the energy recovery water (ERW) loop (5) – which is a closed loop system. There are three heat rejection options for this IT load, which operate in the following hierarchy:
- When possible, heat energy from the energy recovery loop is transferred to the building process hot water (PHW) loop, which provides heat for the office and laboratory spaces within the building. The energy recovery heat exchanger (6) transfers heat from the ERW loop to the PHW loop. The dashboard provides detailed information about input/output temperatures and water flow through both sides of the heat exchanger.
- After re-use potential is exhausted, warm ERW water flows to the 4th floor mechanical room. When temperatures permit, heat is dissipated through a thermosyphon (7), which is an advanced dry cooler that uses refrigerant in a passive cycle to dissipate heat. The dashboard provides detailed information about input/output water and temperatures and flows. Learn more about how this thermosyphon is reducing water usage by the data center.
- Remaining heat is transferred from the ERW loop to a tower water (TW) open loop via the cooling tower heat exchanger (8). The dashboard provides detailed information about input/output temperatures and water flow through both sides of the heat exchanger. Cooling towers (9) cool the TW loop by cascading that water across fill material while drawing ambient air across the fill material. This provides a very energy efficient way of cooling water via sensible (heat dissipated to air without evaporation) and latent (heat dissipated with evaporation) heat transfer. However, this evaporative cooling process requires a continuous source of water.