Eighteen thousand feet of welded steel HVAC piping; 30,000 weld inches; 60 tractor-trailer loads of piping delivered to the jobsite: truly, building out a mechanical system for a large-scale data center can be a mammoth undertaking.
Couple the design, coordination, equipment, and logistical challenges of a data center buildout to an aggressive completion schedule, and the construction project team will find itself with little-to-no room for error.
In light of these factors, what are the keys to a successful mechanical systems buildout for an enterprise-class data center? For us the formula is brief, there are five key components:
Hit the ground running with the team
Anticipate logistical hurdles
Develop a strategic plan
Tap into the latest technology to pre-plan and coordinate design and layout of mechanical systems
Maximize pre-fabrication to expedite installation of system components on the jobsite
The above-mentioned Goliath data center buildout included 240,000 sq ft of raised flooring in four independent computer room environments incorporating redundant backup for the building’s HVAC systems. (To see a five-minute video capturing the highlights of this project, visit http://bit.ly/2eQNFtI.)
The first key to success on a large-scale data center mechanical systems buildout on a tight timeframe 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.
On our Goliath project, the schedule mandated five months (January 22, 2016 to June 22, 2016) from project award to
completion of the commissioning 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 specialized equipment submittals by the engineer of record. The sooner that approval process is initiated, the better.
On any job site, site logistics and coordination are often a challenge. When it comes to a large-scale data center located on a small site footprint, logistics can be an even bigger hurdle. The solution must include efficient staging of equipment deliveries to ensure there is enough room to lay down materials so that system components align properly with each other without getting tangled up with deliveries of concrete, structural steel, and equipment and supplies needed by other trades. This 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 pre-planned and coordinated through the general contractor and site engineer to avoid congestion, delays, and safety issues while off-loading materials. For the most part, deliveries of mechanical equipment and piping were made in the evenings 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 is essential to configure these documents in anticipation of specific site requirements and constraints.
Then, project managers need to 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 in teams to tackle the project in a building block approach. This approach was essential in order to facilitate coordination, design, fabrication, delivery, and placement of approximately 18,000 ft of welded steel and copper chilled water piping ranging in sizes from 10 in. to 3 in. in diameter.
In addition to more than three miles of piping, what else is included in an enterprise-class data center mechanical solution? 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
Three packaged rooftop air handling units
Forty-seven variable air volume boxes
Two chilled water fancoil 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 piping systems for domestic water, sanitary, and storm water
Given a tight data center construction schedule, there is only going to be enough time to do it once. There is no time for rework. Not just mechanical systems, but also 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 is 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 (BIM)/virtual design coordination (VDC) process was put to the test in troubleshooting mechanical and plumbing designs in conjunction with other trades. Job-specific project documentation was assembled working double-shifts in order 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-sq-ft 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 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 3-ft high pedestals mounted on a grid pattern. This raised floor was a critical element to take into consideration in coordination because our BIM/VDC system had to model the 3-ft 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 prior to placement of rooftop steel dunnage and the 20 air cooled chillers.
PREFABBING TO THE MAX
In building out a data center mechanical solution, prefabrication is most likely going to 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 Goliath 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 in anticipation of delivery to the jobsite. 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 ft in length — were pre-manufactured, numbered, and truck-loaded in a sequence corresponding with the general contractor’s schedule. There were over 60 tractor-trailer loads of piping 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, with the piping then lifted to connect to the underside of the steel. This approach eliminated the need to man-handle large pumps and piping under the steel after it was erected, thus 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 ft of pre-engineered custom leak detection systems were installed beneath the various runs of underfloor chilled water piping.
DID WE MENTION SAFETY?
Without a comprehensive safety plan that is 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, must 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 needs to set an example for good communication by encouraging open lines of communication and unhindered dialogue between all team players. In this spirit, everyone can work together while the individual needs of all team players are accommodated.
On the Goliath project, perhaps the best example of the importance of effective on-the-job communication was the quick-turnaround response our team was able to obtain from the design team engineer. On most construction projects, engineering approval on drawings and other project documentation normally takes two to four weeks. Thanks to the communication environment our team created, we achieved three-day turnaround.
Additional best practices related to project communication include daily meetings of key players, which help 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. This helps avoid unforeseen scheduling snags.
The following factors all need to come together in order to achieve success on a large-scale data center mechanical solution constructed under an aggressive schedule and amid difficult site conditions:
Hitting the ground running
Timeliness of deliveries
Ingenuity of pre-construction
Smooth coordination and precise design of piping systems
Meticulous prefabrication sequencing in concert with project schedule and the work of other trades
Superior quality of workmanship, done right the first time
When you have an exceptionally strong team, starting with the mechanical contractor’s own personnel and extending to subcontractors, the general contractor and owner, that is the secret weapon. Goliath doesn’t stand a chance.