Data meets Goliath. It’s no exaggeration that the buildout of the mechanical system for a large-scale data center can include 18,000 feet of welded-steel HVAC piping, 30,000 weld inches and 60 tractor-trailer loads of piping delivered to the job site. Couple these design, construction and logistical challenges with an aggressive completion schedule, and the mechanical construction team could be facing a nearly overwhelming challenge.
In light of these factors, what are the keys to a successful mechanical-systems buildout for an enterprise-class data center? In our experience, which includes several successful data center buildouts (the most recent of which is a 291,000-square-foot facility in Northern Virginia), there are five keys:
- Hitting the ground running.
- Anticipating logistical hurdles.
- Developing a strategic plan.
- Tapping the latest technology to preplan and coordinate design and layout of mechanical systems.
- Maximizing prefabrication to expedite installation of system components on the job site.
The above-mentioned Goliath data center includes 240,000 square feet of raised floor space housing four independent computer-room environments that incorporate redundant backup for the building’s HVAC systems. (See a five-minute video capturing the highlights of this project.)
The first key to success on a large-scale data center mechanical-systems buildout on a tight schedule is to get the project team up to speed as quickly as possible so that design, planning and coordination technology can be applied in the most time-efficient and cost-effective manner.
For our Goliath project, the schedule mandated five months (January 22, 2016 to June 22, 2016) from preconstruction to completion of functional systems. Our team began coordination and project documentation the day after the contract was awarded. All personnel and other resources provided by Shapiro & Duncan and our subcontractors had to be structured for a 24/7 work schedule, including fabrication operations.
Once schedule requirements are established, another best practice is to expedite approval of any equipment that requires special clearance by the site engineer. The sooner that approval process is initiated, the better.
Job-site logistics and coordination are often a challenge. When it comes to a large-scale data center located at a small site, logistics can be an even bigger hurdle. The solution must include efficient staging of equipment deliveries to ensure enough room to lay down materials so that system components line up properly with each other, without getting tangled with deliveries of concrete, structural steel, and equipment and supplies needed by other trades. This approach means a critical path must be followed when it comes to planning and implementing site logistics.
On the Goliath data center project, space for equipment storage and staging was extremely tight. As a result, all deliveries of prefabricated piping assemblies and specialized equipment were carefully preplanned and coordinated through the general contractor and site engineer to avoid congestion, delays and safety issues while unloading materials. For the most part, deliveries of mechanical equipment and piping took place in the evening and over weekends, often during inclement weather.
Strategic planning of the mechanical solution for a data center project must begin with development of requests for information (RFIs) and other design documents. It’s essential to configure these documents in anticipation of specific site requirements and constraints.
Then, project managers must tap both their critical- and creative-thinking skills to fashion the right strategic implementation plan. For the Goliath project, Shapiro & Duncan’s project-management team swiftly implemented a strategic plan that assembled personnel to tackle the project in a building-block approach. This approach was essential to facilitate coordination, design, fabrication, delivery and placement of approximately 18,000 feet of welded steel and copper chilled-water piping ranging in sizes from 10" to 3" in diameter.
In addition to more than three miles of piping, what else does an enterprise-class data center mechanical solution include? Here is the complete inventory of installed equipment for Project Goliath:
- Twenty 553-ton roof-mounted air-cooled chillers
- Twenty 50-HP in-line pumps with variable-frequency drives
- Sixty 154-ton computer-room air handlers
- Sixteen humidifiers
- Three packaged rooftop air-handling units
- Forty-seven variable air-volume boxes
- Two chilled-water fan-coil units
- Water-treatment systems
- Sump-pump systems for dewatering and condensate removal
- Leak-detection systems
- Pipe-freeze protection systems
- Automated temperature-control systems
- Custom spiral ductwork serving office and corridor spaces
- Custom pipe covering (insulation) and duct-insulation systems
- Plumbing fixtures serving office restrooms, breakrooms and janitor rooms
- Plumbing systems for domestic water, sanitary and storm water
Given a tight data center construction schedule, there is only enough time to do it once. There is no time for rework, and that constraint applies not just to mechanical systems, but also to the work done by other trades—concrete, electrical, carpentry, drywall and so on. To make sure all of the work is done right the first time, it’s imperative that things be checked and double-checked in advance, so that quality is not compromised.
Troubleshooting With the Latest Technology
When it comes to coordinating the design and layout of a data center’s mechanical system, the right technology is essential. With advanced computer-assisted design (CAD) software, project designers can create digital representations of the physical and functional characteristics of a building and take the coordination process to a new level of efficiency and effectiveness.
For example, on the Goliath project, Shapiro & Duncan’s Building Information Management/Virtual Design Coordination (BIM/VDC) system was put to the test in troubleshooting mechanical and plumbing designs in conjunction with other trades. Job-specific project documentation was double-shifted to provide needed product information to the BIM/VDC team. As segments of the BIM/VDC process were completed and the coordination drawings approved by all trades, designs were forwarded to Shapiro & Duncan’s procurement team and our 51,000-square-foot fabrication facility in Landover, Md. When you are keeping to a tight schedule, it’s a big help if everybody involved can sign off as various sections of the building are modeled.
At the risk of sounding clichéd, all players on our project team had to think outside the box to arrive at the most effective configuration of the systems that would need to be prefabbed in order to minimize the number of field joints. By taking a comprehensive approach to the planning and coordination of all building elements as they apply to the installed systems, the right technology tools can look at clash detection from all angles and remove the element of surprise from the construction process.
For example, the data center floor sits on an array of three-foot high pedestals mounted on a grid pattern. This raised floor was critical to take into consideration when coordinating, because our BIM/VDC system had to model the two- to three-foot cavity below the floor to make sure mechanical components would avoid the forest of pedestals and fit properly in this tight space.
Shapiro & Duncan’s coordination solution extended beyond piping assemblies to include layout and placement of computer-room air handling (CRAH) units, corresponding to the logistics of sharing limited laydown space. In addition, intricate coordination was required for staging and placement of piping, pumps and related equipment on the unfinished roof before placement of rooftop steel dunnage and the 20 air-cooled chillers.
Prefabbing to the Max
In building out a data center mechanical solution, prefabrication will most likely be the make-or-break component in ensuring swift installation of equipment and staying on schedule. Faced with the installation challenges of the Goliath project, our key question was, How far can we take prefabbing to minimize on-site assembly time? As it turned out, of the 30,000 weld inches required on the project, 25,000 were done inside our fabrication shop.
Approximately one week following contract award, fabrication of piping systems for the Goliath project commenced on a 24/7 schedule so that they could be completed and loaded on flat-bed trailers for delivery to the job site. Piping assemblies including both supply and return lines—complete with pipe supports, insulation inserts, valves, fittings, specialties, pumps and air separators, in sections up to 40 feet long—were premanufactured, numbered and truck-loaded in a sequence corresponding with the general contractor’s schedule. Over 60 tractor-trailer loads of piping were delivered in this fashion. Piping and equipment deliveries were staged so that the material went into the building and quickly came together in Erector Set fashion, expediting final welded connections as well as testing and insulation of piping systems.
In addition, prefabricated piping/pump assemblies were strategically positioned on the roof so that the steel dunnage could be erected above the piping. The piping was then lifted to connect to the underside of the steel. This approach eliminated the need to manhandle large pumps and piping under the steel after it was erected, saving time and eliminating the potential for damaging the roof substrate.
Following erection of the steel dunnage platforms by subcontractors, the air-cooled chillers were craned into place on top of the dunnage using a 460-ton crawler crane. The pre-engineered piping was then connected to each chiller and tied into the piping extending into the building. Inside the building, meanwhile, over 5,000 feet of pre-engineered custom leak-detection systems were installed beneath the various runs of underfloor chilled-water piping.
Safety: Never an Afterthought
Without a comprehensive safety plan that’s tailored to the job site, all of the technology-driven planning, coordination and prefabrication can be compromised by needless injuries and lost labor hours. An effective safety plan must include excavation safety, fall protection, rigging/handling of heavy loads and provision of protective devices such as welding screens. In addition, safety is often a function of training and equipment testing. Welders, for example, should be certified and their equipment should be in tip-top condition.
As the saying goes, success or failure starts at the top. To ensure success on the buildout of a large-scale data center solution, the general contractor must set an example for good communication by encouraging open and unhindered dialogue between all team players. In this spirit, everyone can work together while the individual needs of all team players are accommodated.
Best practices related to project communication include daily meetings of key players, which helps maintain buy-in by all trades, and comprehensive commissioning plans to put system components through their paces as soon as this equipment is ready to be activated. Doing so helps avoid unforeseen scheduling snags.
With an exceptionally strong team, starting with the mechanical contractor’s own personnel and extending to subcontractors, the general contractor and owner, Goliath doesn’t stand a chance.
About the Authors
John Hoke is a Senior Project Manager and Chris Canter is the Director of Virtual Design Coordination (VDC) and Fabrication at Shapiro & Duncan, Inc., a third-generation family-owned mechanical-contracting business serving customers in the Washington, D.C., area since 1976. Shapiro & Duncan is the “provider of choice” for complex commercial, government and institutional design-build projects that require first-rate performance, work quality and customer service.