May 8 2013
Symmes Maini & McKee Associates’ (SMMA) design for the EMC Durham Center of Excellence data center, Phases I and II, in Durham, NC has received LEED Commercial Interiors (CI) Gold Certification from the United States Green Building Council (USGBC).
SMMA’s concept and design of the facility achieves multiple advantages for the owner, including qualifying for $660,000 in power company rebates and reduction of EMC’s overall carbon footprint by 100 million pounds of CO©ü. The building also represents the most ambitious completed data center in SMMA’s Mission Critical design practice.
There were three main sources for LEED points at the EMC facility: Energy savings, water use reduction and sustainable materials and resources, including building reuse.
“Sustainability is embedded into every facet of our practice, and this is an example of a building that fulfills stringent Mission Critical criteria while also being environmentally responsible,” said Dana Watts, AIA, principal in charge of SMMA’s Chapel Hill office and project director for the Center of Excellence. “In addition, in keeping with the motto ‘the greenest building is the one you don’t have to build in the first place,’ the EMC Durham Center of Excellence is the retrofit of a 450,000 sf warehouse facility.” Several existing building components were repurposed as part of the project, Watts added: New materials contained up to 85% recycled content; more than 20% of the materials used were locally-sourced; and 95% of construction waste was diverted from landfills and incineration facilities and recycled back into the manufacturing process.
The primary challenge facing data center designers is to arrange the space and provide systems that keep computer equipment cool. Each design decision for the facility was made to achieve an optimum Power Use Effectiveness (PUE). (PUE is a measure of how efficiently a computer data center uses its power; PUE is the ratio of total amount of power used by a facility to the power delivered to computing equipment.) The Center of Excellence is currently running at 1.26 PUE.
Overall the facility is generating energy savings of more than 34%. SMMA designers focused on ways to cool the space that went beyond reliance on energy-hungry air conditioning equipment. Energy-efficient cooling measures include cold-aisle containment, and high-efficiency humidification, a non-fossil-fuel based high-pressure reverse osmosis system. Even with the warm climate of North Carolina, through innovative HVAC design the EMC Center of Excellence provides over 5,500 hours (approximately 62.8%) of free cooling per year. The qualification for $660,000 in energy rebates is based on the power company’s desire to optimize the electricity delivered commensurate with its available infrastructure. (So, in effect, a power company offers an incentive to a large customer to use less electricity to avoid overwhelming its infrastructure during peak hours.)
The design team also achieved dynamic and uniform airflow throughout the space. Design components, such as large vertical and horizontal plenums, function as extensions of the mechanical system and provide unobstructed airflow paths serving the whitespace. Other airflow design solutions included: High performance floor supply grills, perforated plates to uniformly distribute airflow, minimized differential pressure between under floor and data center and custom Air Handling Units (AHUs) utilizing a multiple fan array approach, thereby reducing connected motor horsepower.
Water use reduction was another major source of points for the LEED certification. One inch of rain on the 450,000 square-foot roof results in 280,000 gallons of potential water reuse. Mindful of this, the team proposed and implemented a system that captures, stores and reuses this water. The end result is a reduction in the use of potable water by 78%. This total is comprised of a 40% decrease owing to the rainwater collection system and an additional 38% decrease through use of low-water flow toilets, waterless urinals and no permanent irrigation system.