NREL Energy Systems Integration Facility
The mechanical systems for the NREL-ESIF datacenter meet the goals of reliability, energy efficiency, affordability and maintainability with thoughtful, whole-system design and the use of standard equipment, applied in a unique, yet straightforward manner. Our design incorporates equipment in an innovative way that substantially reduces building cooling and heating energy, rather than simply installing more costly equipment in typical configurations, which usually results in small incremental reductions in energy use.
Principle energy efficiency strategies include: compressor-free cooling in data rooms 100% of year; high-efficiency fan systems; variable speed primary-only pumping for hydronic; distribution loops to reduce pumping energy; and low pressure drop design to reduce fan and pump energy. Because the supercomputers can be cooled with 71°F water, cooling towers designed for a low approach eliminate the need for chiller operation. Likewise for air-cooled equipment, 77°F supply air with hot-aisle containment allows “medium temperature” chilled water to be used.
Though the office and lab portion of the building use significantly less energy than supercomputers, they are still a concrete demonstration of real-world energy savings to the many annual visitors to the building. Envelope loads are significantly reduced by triple-element windows; moderate window-to-wall ratio; and increased floor, wall and roof insulation. Consequently, the office requires significantly less heating energy than minimum energy code standards: office heat is supplied by energy recovery heat pumps transferring heat from the chilled water return into the hot water supply, which simultaneously pre-cools the chilled water. The office’s thermal comfort is dramatically improved through elimination of drafts and the use of cold radiant heat absorbing windows, among other strategies.