Fabric Ductwork Solves Data Center’s Air Distribution Challenges While Providing Adjustability For Future Expansion
Lansing, MI -- After exploring standard air dispersion and air flow-based solutions to this problem, international data center provider Liquid Web decided to use a more innovative approach when retrofitting its multi-server Michigan location. Rather than using traditional metal ductwork, Liquid Web opted for a first-ofits- kind air-distribution system for rack cooling, using fabric ductwork with directional diffusers.
The project began in 2016. Working with a team of outside engineers as well as internal data center managers, the company developed plans and then betatested a fabric ductwork system to cool the center’s cold aisles. After initial trial success, Liquid Web’s data managers proposed using the new system for a comprehensive redesign of the company’s 75,000 sq. ft. Michigan facility.
As in most data center facilities, Liquid Web’s data centers had long deployed an open-air area strategy for controlling server temperatures. Multiple server rows were spread throughout the vast facility and collectively cooled by a network of traditional metal ducts with air diffusers placed several feet apart along each duct. However, this set-up created hot and cold spots between the spaced diffusers, rather than then consistent, cool environment that each server rack required for peak performance.
Liquid Web facility managers were forced to fully utilize the 39 up flow air conditioning units in order to distribute the necessary airflow throughout the space. Unfortunately, this approach wasted energy and was not effective in cooling the server racks, as airflow was rarely focused towards the load.
“While our existing infrastructure was able to effectively cool the data centers heat load, our facility was not operating efficiently when it came to air distribution and server rack cooling,” said Aaron Reif, data center project manager at Liquid Web. “After the initial focused-air distribution tests, our team was ready to retrofit the entire air distribution process with fabric ducts.”
As digital data usage grows exponentially every year, the costs to operate and cool numerous server racks is proportionally rising. Fortunately, Liquid Web was able to utilize the Property Assessed Clean Energy (PACE) program to partially finance the cost-savings retrofitting project. The PACE program allows for private lenders to fund energy efficient upgrades for buildings in a variety of categories, including heating, ventilation, and air conditioning.
A Retrofitted Layout
The first challenge was converting the open-air facility to a series of directed-air areas. The facility is divided into 8 sections of 12 server rows, each using clear curtain walls. These dedicated sections create focused micro-climates, which allowed for the targeted, controlled cooling of server racks.
Liquid Web’s engineers then turned their attention to air conditioning (A/C). Each of the original 39 A/C units, which ranged from 64KW-90KW, were removed. In their place, 22 A/C units each operating at 165 KW of cooling capacity were installed in the facility. Improving on the outdated loosely balanced A/C system, the retrofitted design operates as an N+1 redundancy environment, covering the 8 server sections seamlessly.
In this setup, the network is built to have at least one independent backup A/C unit in the case of component failure. As the facility’s servers house and protect various company’s essential data, ensuring consistent temperature control and air distribution is paramount.
Air And Data Distribution
With layout and air-cooling concerns addressed, Liquid Web looked to DuctSox to solve one of the most complicated challenges: air distribution.
As part of the new layout, a raised plenum surface was built at the end of each row. Fitted with a customized adapter the fabric ducts extend vertically towards the ceiling. At that point, a 90-degree turn extends the duct horizontally across the length of each narrow server row. In addition to a porous strip of material on the underside of each duct that distributes air throughout the server space, adjustable nozzles force air in targeted directions at the server racks. Each directional diffuser can be adjusted or shutoff depending on the evolving needs of a given row.
“The customization of the fabric duct nozzles solved our air distribution challenges,” said Reif. “Combined with the flexibility to decide the frequency of nozzles along each duct, the fabric ductwork system gave our team the ability to tailor the airflow for each server section.”
Mounting of the duct was another key consideration in this project. Unlike heavy metal ductwork options, the light-weight fabric makeup of DuctSox made ceiling suspension possible. Using a custom hanging system, the fabric ducts are connected to the celling grid and positioned above the cold aisles in each server section allowing for air distribution as close to the load as possible.
“The fact that DuctSox were less expensive than alternatives and incredibly lightweight made this project installation possible,” continued Reif, “As our server demands continue to grow, we’re confident that this air distribution layout can adapt and expand with us.”
The Liquid Web retrofitting project is set to be completed in early 2020.