Warm-Water Liquid Cooling
Liquid cooling technology offers a more energy-efficient solution that also allows for effective reuse of the heat rejected by the computer. The ESIF data center takes advantage of the fact that liquid has approximately 1,000 times the cooling capacity of air and pumps circulating liquid cooling are much more efficient than fans circulating air. Rack power densities of upwards of 60 kilowatts (kW) per rack are achievable using warm-water liquid cooling requiring less floor space (where air-cooled racks struggle to reach 20 kW per rack power densities).
The ESIF HPC data center is cooled without mechanical refrigeration. Indirect evaporative cooling takes advantage of NREL’s semi-arid climate with 60°F design wet bulb temperature. The relatively warm (up to 75°F) water used for computer cooling allows the data center to use highly efficient evaporative cooling towers. It circulates through heat exchangers in the HPC systems to efficiently capture waste heat. The water is heated to around 100°F by the HPC systems and utilized as a source of heating for laboratory and office spaces in the ESIF.
Key Design Parameters
- IT cooling supply – the ESIF can produce 75°F on the hottest day of the year through the use of cooling towers
- IT return water – require 95°F to heat the facility on the coldest day of the year