Sandia LabNews

Colorado national lab cuts water use in half, thanks in part to Sandia

DOE honors Martinez for help at data center

A Sandia engineer shared a DOE environmental award for halving the amount of water used last year to cool a high-performance computer data center at the National Renewable Energy Laboratory in Golden, Colorado.

David Martinez, engineering project lead for Sandia’s infrastructure computing services, received the DOE’s Federal Energy and Water Management Award for contributions to a water-saving technique that substitutes a reusable liquid refrigerant in place of evaporative-water cooling towers when outside temperatures are low enough to make that feasible.

David J. Martinez examines the cooling system at Sandia’s supercomputing center
KEEPING HIS COOL — Sandia engineer David J. Martinez examines the cooling system at Sandia’s supercomputing center.

Sandia plans in 2019 to complete installation of a similar system using the technique, David said. The advance is credited with saving NREL 1.15 million gallons of water last year, and he anticipates even more savings at Sandia, which has more high-performance computers.

The refrigerant’s cooling process doesn’t require an electrically powered pump. Instead, it relies upon simple convection for the fluid to rise to a location where it can give up heat to water enclosed in a tube of its own. The water rises to give up heat to the outside air, then drops as it cools and absorbs more heat from the returning refrigerant in a continuous shuttling cycle.

Unlike water cooling towers, no water evaporates during the process, which works when the outside temperature is at most a few degrees warmer than the heat being given off by the water. If the air is warmer than that, the evaporative cooling towers kick in. The combined process is called hybrid thermosyphon cooling.

More efficient facility designs also are employed to cool down the rooms housing the computers, said David. Improvements such as smart fans that self-adjust to blow only the air needed, without creating air whorls that themselves require more cooling, mean a syphon can cool even hotter rooms without need for the evaporative cooling tower.

The environmental awards recognize people and organizations who have made significant contributions to energy and water efficiency within the federal government.

“l like those guys. They’re like me: they push the envelope in saving energy and water.”

David, who travels monthly to NREL to work on energy efficiency, shares the award with NREL scientists David Sickinger and Kevin Regimbal, along with Tom Carter of Johnson Controls and DOE’s Matt Graham. 

“I helped as a consultant on the design of NREL’s data-cooling center for their first high-performance computing system,” said David, who has 30 years of experience putting together heating, cooling and power systems. “I work with them on different systems. I collaborate on fuel cells, liquid cooling and other improvements. l like those guys. They’re like me: they push the envelope in saving energy and water.”

The victors will receive their awards on Oct. 23 at a ceremony at the United States Institute of Peace in Washington, D.C.