FTG ENG | eBooks

A S H R A E J O U R N A L a s h r a e . o r g M A Y 2 0 2 1 2 4 Construction Because augmented reality connects the physical and digital worlds, the technology helps make design intent a reality, Lawver said. Extended reality technology can be used at any stage of the construction process, he said. "Ultimately, the primary benefit that any mixed or augmented reality technology provides to anyone on the construction site is the ability to understand their design in context," said Lawver. There, people can use AR overlays to see where certain systems will be located and how the project will be built. During construction, Messner said contractors can use AR to view future construction content on location in the field prior to its being built, or they can see "through" walls to see inside or underground if accurate utility models exist. But quality assurance and quality control (QA/QC) as well as validation and progress reporting are currently the technology's biggest use cases, said Lawver. AR can help someone on the construction site overlay the design as it's supposed to look on that given day and be able to correlate the difference between the digital model and the actual built condition on-site. "If something's missing or something has been installed in the wrong spot, or if they're ahead of sched- ule and they've put more in than you expected them to at that point, all of those things become glaringly obvi- ous when you overlay the design to the real world," he said. Ghorbani said Penn State is using AR technology for design evaluation by overlaying the digital model of a building on the actual site. In addition, AR is used for QA/QC by comparing the digital model of a building with the constructed part of the building. The Office of the Physical Plant is in the midst of its first project using AR, she said. "The project team is in the early construction stage and overlaid their digital model on the site using AR head-mounted displays. Since the project is not on the University Park campus, we are planning to join the AR review meetings remotely by connecting through remote assistance," said Ghorbani, adding the team is using software that allows them to see through the AR lenses from anywhere. Prefabrication AR can also help the prefabrication process. Some technologies have sequencing tools that walk people step-by-step through how to put a system together, said Lawver. If an HVAC&R assembly is being prefab- ricated for a project, the people assembling the system can put the pieces together in order with precision. The technology also allows people to see where systems will be placed to line up with a specific duct run or another specific, he said. This guidance can help direct assem- blers to better put together prefabricated systems, eliminating rework. Conversely, AR can guide people on the construction site how to install the systems to be more efficient, said Lawver. Lawver saw the need to precisely design prefabricated systems a few years ago on the construction site of one of Trimble's office buildings. While on-site with the general contractor and HVAC&R contractor, they uploaded the mechanical model into an AR headset and started walk- ing the project. "Within 10 minutes, there were three different loca- tions where the mechanical contractor recognized that they were due to have an HVAC run go through a very specific spot, but it wasn't going to work," he said. At that stage of construction, steel, framing and plumbing was done, and the team was getting ready to install prefabricated systems, according to Lawver. He said it seems the steel contractor made a few changes on their install and added a couple ceiling beam steel kickers. "The HVAC guys had no idea that those kickers were there, but what that meant now was that they were in the process of prefabricating all these HVAC runs off-site," he said. "They were going to show up on-site, and they weren't going to fit in a couple areas. So they were either going to have to get it redone and have guys sitting around not knowing what to do or, worst-case scenario, they would've hacked them to fit in there anyway, which would've just then snowballed the issue to the next guy." Because the HVAC&R contractor saw this issue before the material showed up, they were able to take photos with their AR technology to send the HVAC&R designer, which helped the user accurately capture the "mixed reality" view that showed their off-site team members the actual issue. "They updated the design before the prefab shop was done and before they got shipped to INDUSTRY 4.0

• Cover