Because laboratory buildings can consume up to 10 times more energy than office buildings, Arizona State University needed efficient systems to achieve its sustainability goals for the new seven-story Interdisciplinary Science and Technology Building IV on its Tempe, Ariz., campus.
Using strategies such as variable exhaust and intelligent sensors, the structure, now under construction, is modeled to use 41% less energy than a typical research lab, says Mohammad Madjidi, ASU's senior project manager.
The university committed to LEED Silver or greater, but it also has its own set of sustainable guidelines. “They are a supplement to the LEED process to clarify those areas of construction that best reflect the university's sustainability practices, goals and desired outcomes for high-performance buildings,” Madjidi says.
The 294,000-sq-ft building will bring together the Fulton Schools of Engineering with the School of Earth and Space Exploration so that the engineers who build scientific tools can co-locate and interact on a daily basis with the scientists who use the tools for research.
In a similar spirit, members of the project team also co-located during much of the pre-construction phase beginning in early 2009. Design architect Ehrlich Architects of Los Angeles and construction manager-at-risk Sundt Construction of Tempe moved key personnel into architect-of-record HDR Inc.'s Phoenix office to share Revit and other BIM drawings. “It allowed us to collaborate, check each other's work and divvy up tasks in far more specific ways,” says Mathew Chaney, design project manager with Ehrlich.
Just as the team was wrapping up the construction documents, the state of Arizona abruptly put the project on hold due to the recession. As a result, groundbreaking didn't occur until March 2010. “While the delay didn't help ASU with its research space needs, it did help with making the project more affordable by taking advantage of the market,” Madjidi says.
The guaranteed maximum price for the building dropped by $25 million to $109 million once the project re-started. Completion is scheduled for May 2012.
Nearly 25% of the budget is for the construction of the complex mechanical systems, says Ryan Abbott, Sundt's project director. “In a typical wet lab, you get close to 15 air changes in a lab per hour, but this building seeks to reduce those down to four or five.” Air control valves on fume hoods are linked to occupancy sensors so that a hood is not needlessly running at full power when there is no researcher nearby to protect.
Enhanced air sensors also dictate whether an increase in air changes is necessary by monitoring various gases. “We also used energy heat/cool recovery systems in the building. Because you are using so much single-pass air, the cooling load of bringing desert air into the building is really an enormous expense,” says Michael Jackson, vice president with HDR.
Labs with high air usage were placed adjacent to each other and near massive air exhaust shafts that run the full height of the building on two sides of the cast-in-place concrete structure. With each air change estimated to cost $4.28 in this building, according to Abbott, these strategies will save both energy and money.
The most complex labs, including a metal-free space for experiments that involve highly corrosive acids, are located in a basement level. The first and second floors are primarily public and gallery spaces for the display of meteorites and other rocks. The remaining floors contain offices, classrooms and additional lab space.
The building requires separate exhaust strategies based on the types of chemicals used in the labs. The team devised four exhaust systems: galvanized duct, stainless steel duct, stainless with the addition of a wash-down component and, for the corrosive labs, fiberglass reinforced plastic duct, Jackson says.
Nearly 30,000 utility hangers were incorporated into the BIM model to ensure there would be space to hang the large amount of ductwork and piping needed, says Brian Wieneke, project manager with mechanical contractor Dynamic Systems Inc., Austin, Texas. These points were then transferred to a laser total station, which allowed installers to place rod anchors into the formwork prior to the deck pours. “This was a huge time saver for the install crews,” Wieneke says.
BIM also helped subcontractor crews limit construction waste by facilitating pre-assembly of large sections of sheet metal and piping, Abbott says. Subcontractors are working with BIM models to drive computer-controlled manufacturing equipment for fabrication.
The pieces are assembled in the factory into 20-ft to 30-ft subassemblies, which are then transported to the site and installed. Abbott says that offsite pre-manufacturing enhances efficiency and safety, since workers are spending less time reaching above their heads to install pipe at the jobsite.
With these strategies, the project is currently on track to receive LEED Gold certification.