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3D Scanning: Adding another dimension to your toolbox

Steve Tredinnick, PE, CEM, Senior Project Manager, OnSite Energy & Power Group, Burns & McDonnell

Editor’s Note: “Inside Insights” is a a three-dimensional XYZ coordinate sys- your computer are not too extreme either. column designed to address ongoing tem. The resultant scan is called a “point With an upgraded graphics card, more issues of interest to building owners, cloud.” This cloud is not the same place RAM and a solid-state hard drive, I could managers and operating engineers who where your iPhone pictures reside; rather, actually run the software from my laptop; use district energy services. it refers to a cloud of geometric shapes but the more powerful the computer, the or points on the surface of the scanned faster the effort. t is time to put your camera and object. These points are then used to ex- measuring tape at the bottom of your trapolate the shape of the scanned item Why Would You Use It? Itool box and learn about something in- and reconstruct them in an image file. You would use 3D to novative – 3D laser scanning. I know this There are several types of scanners make life easier, of course! It eliminates column is supposed to focus on customer that are used in different industries. In our the sore necks and backs from looking up building-side topics, but I thought that business, the stationary 3D laser scanner all the time while using a measuring tape. the readership might find this technol- is the most common type. Once located I always had the measuring tape fold in ogy interesting and potentially useful. in the subject space – i.e., chiller room, on itself, getting “the bends” at the most are not a new technology, since we boiler room, pump room, etc. – the scan- inopportune time as I was measuring the have been exposed to laser/CD/Blu-ray ner spins 360 degrees in place, capturing underside of a pipe or duct. Extremely discs, far-out laser shows, , laser all surface data within the laser’s effective annoying. About a decade ago, we gradu- range finders, laser pointers (awesome range. The number of scans made and the ated to a laser distance finder, which for tormenting your pets) distance between the scans depend on greatly improved the speed of obtaining and now laser scanning in 3D. Yep, just the level of detailed information required. measurements, but those measurements like today’s latest technology in TVs, site The closer together the scan locations are, still had to be written on paper and the surveys are now available economically the more detail there is; the farther apart dimensions input into a computer-aided in 3D, and you don’t even need special they are, the less detail there is design drawing once back at the office. glasses to see them! Each scan uses several reference Very time-intensive. In contrast, today 3D targets that “ground” the image into the laser scanning provides a quicker, safer What Is it? base coordinate system as the scan- and more accurate method of collecting 3D scanning is often called “,” ner is moved through the space. The data on existing site conditions. which some say is a combination of the scanned point cloud files are then input words “light” and “radar,” and others into software that manages the data Who Would Use the Information? say is derived from “light detection and using automatic object recognition, scan Project managers, engineers and ranging.” Either way, LIDAR was actually registration and positioning. The software designers can navigate through the point developed in the 1960s and used on the stitches several scans together to give the cloud data to analyze the existing condi- Apollo 15 mission in 1971 for mapping big picture. Each scan is extremely accu- tions and measure distances with confi- the surface of the moon. A 3D laser scan- rate and provides precise measurements, dence knowing the information is accurate. ner provides an accurate measurement of either indoors or out, to within +/- 2 mm. The benefits of 3D laser scanning go far be- the distance from an object’s surface to The subsequent image file actually yond just viewing and measuring. The point the scanner position. The scan of the ob- looks like a picture, except you can actu- clouds are referenced into design applica- ject’s surface comprises many thousands ally maneuver through the image in vir- tions like AutoCAD to improve the overall of individual points that are mapped in tual reality. The system requirements for quality of the design documents. With the

District Energy / First Quarter 2015 59 exact existing conditions referenced into existing architectural, equipment, piping How Much Does It Cost? the AutoCAD design model, your new de- and conduit information. Sixty-five high- The cost to purchase a good-quality sign is more accurate than is possible using definition color scans were collected that 1,000-ft-range scanner, tripod, battery the old of a tape measure and cam- averaged 12 minutes per scan with three charger, reference spheres and training to- era. Furthermore, the contractor could use minutes between scanner relocations. taled around $67,000; however, the cost to the model during construction to provide That amounted to a total of 24 hours of my chiller project was only around $7,000 the owner with precise record drawings. on-site labor for the scanning. Then it plus travel expenses. Well worth the price, took around another 18 hours to process, considering the benefits to the project, and What Projects Are Good clean up and convert the scans for use. now I am totally sold on those benefits. Candidates? See figure 1 for a 3D slice through the The technology is advancing quickly, and This technology is well-suited for any entire facility involved in this project. most mainstream engineering and design project with existing construction that What astounded me was that the application software can read the 3D point needs to be documented – e.g., structures, scanning took place at the beginning of cloud data and provide tools to leverage equipment, piping, etc. – and that has criti- the week, and by Friday morning for the the data to enhance the design. Each time cal connection or penetration locations. kickoff meeting with the client, there was we use the scanner, we discover new ways This especially includes older projects that already an adequate level of detail for to harness the point cloud information and were designed prior to 3D CAD model- a 3D virtual tour of the facility. I was a provide a better engineering product for ing. Scanning is becoming the standard believer after that. our customer. method for capturing existing conditions Furthermore, during the project In closing: Documenting “as-built” due to its accuracy and low cost. It’s not a design, we referred to the scans quite conditions has often been a tedious, pain- matter of if you will be using laser scans often and imported the data into our ful and inaccurate process, and bringing on your projects but rather a matter of CAD models. The architect and structural a tape measure to the job site is quickly when. I can personally vouch for this, engineer used the scans to ensure the becoming obsolete. Data collection using since I was a nonbeliever prior to using building addition matched correctly to 3D scanning essentially allows one to laser scanning in designing a chiller plant the existing building components and bring the job site to the office for the ben- addition; but now I am totally sold on its structure, and the mechanical/electrical/ efit of the entire team. Popcorn and funky benefits. It saves time and still provides plumbing engineers were able to use glasses are always optional. valuable information to the project even them to accurately locate the connec- after the documents have gone out to bid. tions for new pipe, duct and conduit. In- Author’s Note: I thank Jim Smith, build- terference detection could be run against ing information modeling (BIM) services How Long Does It Take? other engineering disciplines and against manager with Burns & McDonnell, for his On the project mentioned above, ap- the 3D point cloud to confirm that all assistance in providing content, including proximately 13,000 sq ft of chiller, pump, components can be installed as intended. costs, for this article. electrical and boiler rooms on multiple We also have added confidence that floors were scanned to capture the critical what was designed will fit. Steve Tredinnick, PE, CEM, is senior project Figure 1. Virtual Slice Through a Chiller Plant Design Project. This combines the image, manager with Burns & composed of 65 laser scans, of an existing chiller plant (left two-thirds of the slice) plus McDonnell’s OnSite the interface of an AutoCAD Revit design of a new plant addition (right one-third). Energy & Power Group. He has more than 30 years’ experience related to building heating, ventilation and air-conditioning systems. The past 20 years of his work have been focused on district energy systems. Tredinnick is a graduate of Pennsylvania State University with a degree in architectural engineer- ing. A past IDEA board member and a member of ASHRAE, he is past chair and current handbook chair of ASHRAE TC 6.2 District Energy and current chair of the Chilled Water Plant Subcommittee of ASHRAE TC 6.1 Hydronic and Steam Equipment and Systems. He may be Source: Jim Smith, Burns & McDonnell. reached at [email protected].

60 District Energy / First Quarter 2015