ASHRAE Journal - May 2021 - 24

INDUSTRY 4.0

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 schedule and they've put more in than you expected them to
at that point, all of those things become glaringly obvious 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

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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 prefabricated 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 assemblers 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 walking the project.
" Within 10 minutes, there were three different locations 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

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