How to design data centers: Energy efficiency and sustainability
An expert panel provides engineering and design tips to design energy-efficient data centers in this Q&A
- Peter Czerwinski, PE, Uptime ATD, Mechanical Engineer/Mission Critical Technologist, Jacobs, Pittsburgh
- Garr Di Salvo, PE, LEED AP, Associate Principal – Americas Data Center Leader, Arup, New York
- Scott Gatewood, PE, Electrical Engineer/Project Manager, Regional Energy Sector Leader, DLR Group, Omaha, Neb.
- Brian Rener, PE, LEED AP, Mission Critical Leader, SmithGroup, Chicago
What level of performance are you being asked to achieve, such as Uptime Institute tier guidelines, WELL Building Standards, U.S. Green Building Council LEED certification, net zero energy, Passive House or other guidelines?
Scott Gatewood: Building performance measurements and achievements continue the march toward lower net energy consumption and emissions. This is true in the mission critical space. Along with concurrently maintainable measures for resilience first established by the Uptime Institute consortium organizations like The Green Grid have expanded the important sustainability measurement systems to include useful measures such as, water use efficiency in volume/unit energy. Additionally, both waterside and increasingly air-side economization practices have advanced in acceptance.
One notable approach that DLR Group has fostered in the Midwest is the symbiotic integration of a detention cell and effluent facilities discharge waters as a primary heat rejection system to achieve a WUE of zero. Combining digestor gas generation, for energy storage production and effectively creating a microgrid, the water-energy cycle and waste recycling are a part of the net energy reduction.
What types of sustainable features or concerns might you encounter for these buildings that you wouldn’t on other projects?
Scott Gatewood: Sustainability features and concerns are a part of the practice of design. However, educating clients is of increasing utility for mission critical facilities design. Teaching and fostering best practice is key. Simple educational modeling of selecting Energy Star rated IT equipment pay huge benefits to the energy use profiles and the organization’s bottom line. On this educational stewardship theme, whether our team drive cabinet implementations or not, we foster air management implementations from the rack unit level all the way to the maximizing optimal return temperatures for the greatest energy efficiency. In other building types, design does not commonly have these levels of influence and control over equipment selections
What types of renewable or alternative energy systems have you recently specified to provide power?
Brian Rener: With the significant demand for conventional diesel generators there has been a push to explore natural gas and alternative fuel sources such as fuel cells. In addition, some major data center clients are starting to deploy large scale utility interactive lithium ion batteries in place of fossil fuel generators where utility power is very reliable. Lastly the power needed to run conventual chiller systems is being replaced by “free cooling” using outside air and even alternative waste heat water rejection sources such as sea water.
How has the demand for heat recovery technology influenced the design for these kinds of projects?
Peter Czerwinski: Generally, heat recovery technology implemented into data center projects is difficult to justify financially. Data center waste heat is low-grade despite its abundance. Heat can be recovered using various heat exchangers and supporting utilities, but oftentimes it shows a longer payback period than the customer is willing to accept. Heat recovery is usually on the list of items to analyze early in a data center design project, but is rarely implemented.
Brian Rener: Heat recovery is a major opportunity where a data center or high-performance computing center can be paired with other multiuse spaces or buildings such as office or laboratories. We have successfully used data center waste heat in multiuse buildings and on large campuses with other buildings.