The central modernization factory on Microsoft’s East Campus is proof of the tech giant’s commitment to sustainability. Heels and other apparatus were prefabricated. Photo via Sean Airhart/NBBJ
Microsoft’s Thermal Energy Center, a revolutionary geothermal heating and cooling formula that serves the tech giant’s East Campus buildings spanning 72 modernized acres outside Seattle, was actually two exotic projects combined into one. However, through the synergy of collaboration, virtual design and construction, modular delivery, and carbon emission reduction, the TEC team has led by example in delivering smart, sustainable projects that can be implemented in many types of buildings.
At the heart of the TEC is the two-story central application plant, permanently on display as a symbol of Microsoft’s global commitment to sustainability. Seventy-five percent of the plant’s mechanical and electrical appliances were prefabricated off-site in controlled environments.
The TEC’s radically different and most intimidating component is its 6. 5-acre geothermal well, comprised of some 900 wells drilled blindly into uncharted territory, many of them as high as 550 feet. Think of the well box as “a giant buried heat exchanger,” says Robvia Oylear, mechanical and electrical engineering task manager for Affiliated Engineers Inc. Of the 15 geothermal systems built through AEI, Microsoft’s is the largest.
The teams built the application plant layout around their mechanical equipment. Photo via GLY Construction
The pit field presented obstacles as the base ground is covered with the remains of buildings beyond and rocks, pebbles, and boulders, none of which are documented. The formula will also be built around existing and long-term lines of application for other campus assignments. The underground situations were challenging,” says Ben Hamm, task manager at general contractor GLY Construction.
The TEC plant was built from August 2020 to the end of June 2022; the geothermal system from February 2020 to March 2022. In spite of the obstacles, the team completed the project on time and under budget, reports GLY. Microsoft is not releasing the cost or any related details.
The closed-loop geothermal heating and cooling formula sends hot or cold water to exchange energy with the deep earth. The box features 6-inch-diameter wells that contain a circuit of water-filled pipes that absorb energy from the Earth. The wells are connected at their top, at least 6 feet underground, via transverse pipes to the 63,726-square-foot application plant.
In addition to the effort, everyone characterizes the project’s good fortune as due to a thoughtfully choreographed effort that relied on the collaboration and cooperation of the entire team. This included a pre-construction phase for GLY and design assistance contracts for MacDonald Miller Facility Solutions for mechanical and Valley systems. Electric. Savings of about $15 million were achieved by upgrading redundant mechanical equipment, which most likely would not have been imaginable without design assistance, says AEI’s Oylear.
The virtual design and structure supported the activities. This included a detailed 256-inch three-dimensional style that became a virtual twin, says Mike Green, director of building systems for OAC Services Inc. , the owner’s representative. A consolidated BIM execution plan, setting the criteria of the project, is essential, he adds.
“BIM was the single source of truth for design and construction,” agrees Chris Beza, a principal for the architect NBBJ. “It was a game-changer for us,” adds Tim Brockway, a principal for the project’s civil engineer, Coughlin Porter Lundeen, also the structural engineer.
The external structure improved quality and protection and minimized box paintings. For example, the steel-framed elevator accounted for six weeks of painting in the box, but only required 10 days of painting in a controlled environment, says GLY’s Hamm.
At TEC, mechanical and electrical systems have taken priority, which represents a radical change. For example, the metal arrangement built around the equipment. The metal rigger had two 30-square-foot clearances at the moment point and on the roof of the two-story building to allow the cranes to fly toward the pumping platforms. The installer then returned to complete the design. Steel contractors prefer to mobilize and demobilize only once.
The geothermal system exchanges energy from the earth’s depths through looped piping in wells. Illustration by Hannah Olson
The combined methods resulted in only 247 requests for information, from the issuance of structural documents to commissioning, Green says. “There can easily be 2,000 queries for a task this size,” adds Green, who says the queries cost $1,080.
The TEC’s heating capacity is 28 million BTUs per hour. Its nine chillers can supply 9,000 tons of refrigeration. The formula is sized to cover 3 million square feet of space and amenities in 17 new buildings, four of which have yet to be built. constructed; two existing buildings; and an underground garage on the Redmond, Washington, campus.
Lately the field is covered with cricket and softball fields, basketball and pickle courts, paths and landscaping. Other contractors on campus “have effectively installed all of the [surface] elements after us, without damaging the geothermal formula so far,” GLY says. Ham.
Work on the 6. 5-acre geothermal well can be done simply segment by segment, in small spaces borrowed from other campus modernization contractors. This reduced productivity. Photo courtesy of Dan DeLong for Microsoft
The TEC’s plant, which in addition to chillers, pumps, risers and electrical equipment for the geothermal system, includes emergency generators and other components, is paired with 280,000 gallons of thermal energy storage at maximum capacity, in seven tanks alongside the building. The water is distributed across four hot- and three cold-water storage tanks, each 65 ft tall and trucked in from across the country. A distribution system connects to the buildings to complete the heating and cooling system.
According to the AEI, the primary function of the tanks is to enable TEC’s heating and cooling appliances to operate as successfully as possible, rather than having to satisfy the rapid conversion desires of the campus.
Each of the seven 65-foot-tall thermal power tanks were trucked to the site from across the country and airlifted next to the central power plant. GLY Construction Photo
The closed-loop geothermal formula is made up of 24,000 linear feet of water-filled plastic pipe in deep geothermal wells. The pipes in the well are looped: one side for the feed water and the other for the return water (see diagram, opposite page).
The rationale for geothermal energy exchange as the main component of the heating system was based on the campus’ open green space, says Oylear. Though not the least cost solution up front, geothermal does ease the burden on the electrical utility, which saves on operating expenses, he adds. It is “very durable and resilient” and is highly efficient when compared to the base option of electric resistance heat/hot water boilers, says Oylear.
The project’s thermal energy storage tanks, four for hot water and three for cold water, contain a total of 280,000 gallons at their maximum capacity.Photo by Sean Airhart/NBBJ
Operationally carbon neutral through renewable energy sources, the TEC aligns with Microsoft’s global sustainability goals, which include a carbon negative and water positive adjustment through 2030. The project also integrates approximately a portion of the embodied carbon in the structure initially planned by the team, through use of the embodied carbon in the structure (EC3) calculator, published in 2019 and which can be downloaded for free on the Building Transparency website.
An example of reducing carbon emissions in transportation is the fuel used in TEC’s waste trucks: renewable biodiesel, made from recycled fats, used cooking oils, and non-edible oils. GLY bulk the fuel from Oregon and stored it in a tank on-site.
Pipe riser on its way into position was among 75% of the plant’s prefabbed components. Photo by GLY Construction
Microsoft is using all the campus modernization projects as a coordinated pilot project to improve EC3, which allows teams to compare the embodied carbon in major construction materials and systems, from mining through construction. So far, the campus-wide EC3 pilot has been “a resounding success,” said Jeff Rovegno, senior development manager for Microsoft Real Estate & Facilities, in an email to ENR. “We integrated the tool into the modernization project’s core strategy with the five architects, three general contractors and multiple structural engineers, and are on track to reduce our embodied carbon footprint by a targeted 30%,” Rovegno added.
Microsoft hopes the EC3 pilot will make it less difficult for groups around the world to use EC3 to reduce embodied carbon. “We, EC3, can drive great innovations throughout the structural industry,” says Rovegno.
Offsite construction also reduces embodied carbon, in part because there is less waste in a factory environment, fewer deliveries and crew trips to the site and a shorter site schedule.
For owner’s rep Green, the TEC plant presented a rare opportunity to “set the table” to realize the potential of modular delivery for mechanical and electrical equipment. At an early team meeting on modular, “I saw the eyeballs of the design-assist ME trade partners get really big” with excitement, says the 40-year construction veteran, with a strong penchant for prefab because he came up through the trades as a pipe fitter. ME subs, eager to prefabricate, are often frustrated by a reluctance on the part of designers and contractors to embrace modular, especially in commercial development, Green has learned.
A validated BIM also empowered the ME trade partners to commit to more prefab than is usual, says Green. For modular to work, the TEC “had to be built first virtually, to perfection, and then followed up by verification,” in the physical world, adds Green. On the TEC, “QA-QC was not just lip service.”
GLY built its BIM structure by layering it on top of the most sensitive part of the highly subtle design model. At the end of the design progression and at the beginning of the CDs, MacDonald Miller took over the spatial coordination of the model. Conflict detection was performed on a weekly basis.
The strategy worked. The first prefabricated module placed within a permissible radius of 1/8″ of the BIM, says Green.
The TEC also serves as a living exhibit to see the operation of the Green Force plant from the outside. Photo via Sean Airhart/NBBJ
Delicate geolocation paintings have also benefited from BIM. The style included existing and planned well positions, distribution pipelines and utilities outside of the GLY contract.
AEI developed the initial plan for preconstruction of potential geowell sites. GLY and MacDonald Miller then used the plan to conduct initial underground surveys and developed the initial BIM to identify potential geothermal well sites included in the geothermal contractor’s request for proposal. When the contract was awarded to GeoTility, MacDonald Miller and GeoTility had number one custody of the model, with oversight and coordination with GLY.
Creating the style was not easy. To expand an excavation protocol for each well domain, the team carried out a “caving” study, which consisted of hydroexcavating issues around the perimeter of a domain to identify whether there were active publics, before connecting the dots to create an excavation. map.
A significant challenge in making plans for the geothermal formula was locating the area for all geothermal drilling below the congested field. “The campus is huge in terms of surface area, but to achieve a green area would have required installing an excessive amount of pipes throughout the site,” says AEI’s Oylear.
Bores were spaced 15 ft on center instead of the more common 20 ft. In addition, the depth was typically 550 ft, not the more common 300 ft. Through a design-construction optimization process, the team determined that the quantity of bores could be reduced by about 25% through a combination of increasing bore depth by 10% and the addition of electric hot water boilers to offset about 30% of the peak heating demand.
Electric boilers are a much smaller initial investment than geothermal drilling capacity and would only be used on the coldest days of the year, Oylear says. This has only resulted in a slight reduction in the overall energy output of the campus, he adds.
The optimization charts highlighted a vital facet of all-electric formulation design that AEI has brought to other projects. Heat pump formulas are more expensive, especially when combined with a geothermal source, than non-heat pump formulas. The way to compensate for this is to extend the heat pump component of the formula based on the majority of operating hours of the year, and extend an additional formula to work in combination with the heat pump formula the few hours of the year in which requires full loading of the formula, Oylear explains.
Geowell’s drilling lasted two years. GLY had permanent custody of part of an acre of land. The other well spaces had to be “borrowed” from other contractors on campus.
“Instead of drilling the whole box at once, which is preferable, we had to place these paintings in series in seven separate areas,” about 40,000 square feet, says GLY’s Hamm.
The small zones were a consequence of many factors, including existing building demolition and the areas controlled by other general contractors for materials storage, crew tents or new utility installations, which included electrical service, sewers, domestic water, site lighting, data and more, says GLY.
The goal was for these utilities to be installed after the geowells in the 6-ft-deep area between the geowell system and the surface, but in some cases they were below or parallel. That required extra coordination, says Hamm.
GLY used drone flights to assess and plan for future drilling areas prior to getting those spaces turned over temporarily by the other contractors. “We would assess” visible obstructions, elevations, square footage and slope via the drone, says Hamm.
After excavating 6 ft and leveling a section for drill rig stability, crews would bore a hole, using mud rotary drilling, insert the 1.25-in.-dia looped piping and fill the bore with grout. “The magic was keeping the hole open to insert the loop,” says Stuart Yanow, GeoTility’s president. Collections or groups of geowells were then pipe-manifolded together to a vault and distributed via larger-diameter pipes back to the central plant.
There were workarounds caused by the geology, including abandoning and relocating some bores. “Most of the time, you drill through an obstruction, but it takes longer, wears down drill bits and generally slows overall productivity,” says Yanow. In some cases, “we tried and tried but couldn’t get to the 550-foot depth,” adds Ben Leventer, MacDonald Miller’s senior project manager.
Hamm remembers being in “panic mode” when the drilling rig hit rock it couldn’t drill, usually deep in. In those cases, which accounted for 25 of the 900 wells, the team drilled up to 400 feet and then discovered other gaps to fill the wells while still meeting design goals. “We redesigned the construction of the formula,” explains Leventer. “If we were 150 feet short in one well, we had to make up the shortfall somewhere else,” he adds.
TEC’s task also resisted external forces, adding a carpenters’ strike and a truckers’ strike that halted concrete deliveries. Although most of the concrete work, which GLY did itself, during the time the strike began, GLY had to combine 33 cubic yards.
COVID-19 and bad weather also had impacts, during a total of 26 days of closure. “We lost 11 days because of the weather,” six of them because of snow, one because of excessive heat and four because of poor air quality, Hamm says. The remaining lost days were due to a delay in the approval of civilian permits.
Looking back, CAO Green emphasizes the importance of setting expectations from the start of the work and communicating goals regularly. “Hold team members accountable for the process,” he advises owners, and first create the task according to the style. “If you can’t build it perfectly in the style,” which has the same XYZ coordinates as the physical world, “there’s little chance you’ll be able to build it properly in the genuine world,” Green says.
An elaborate BIM execution plan is critical to success. “The time spent on modeling and collision detection is equivalent to pennies on the dollar to locate a wrong construction,” he says. Trust the equipment but “check the paints in the opposite position to the model,” he advises.
Microsoft’s Rovegno also advises owners: “Choose highly collaborative companies” with a track record of executing complex jobs with tight deadlines.
AEI’s Oylear summarizes the work: The TEC “was a professional undertaking for everyone involved. We believe this task was ahead of its time [and yet] regulations are beginning to catch up, so most likely is that we will see more allocations in pursuit of similar strategies.
Nadine M. Post, ENR’s editor-at-large for buildings, is an award-winning journalist with 45 years of experience covering trends, issues, innovations, controversies and challenging projects. Post has written about many industry giants, including 10 ENR Award of Excellence winners. And she has covered disasters, failures and attacks, including the 1993 bombing and the 2001 destruction of the World Trade Center. Project stories include the redevelopment of the World Trade Center; the 828-meter-tall Burj Khalifa; Los Angeles’ Disney Concert Hall; and Seattle’s Bullitt Center and Rainier Square Tower. In 1985, Post wrote McGraw-Hill’s book Restoring the Statue of Liberty (1986) for the restoration’s architects—Richard S. Hayden and Thierry W. Despont.
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