Mechanical, Electrical, Plumbing Series: Tips on Scanning MEP Sites from HH Angus



Guest Blog Written by: Melissa Parry, HH Angus

At HH Angus, we’ve worked with thousands of clients, providing consulting engineering services in the institutional, commercial and industrial sectors, along with a deep portfolio of work in both energy generation/distribution and technology. 
This three-part post explores our multi-year project at Toronto Western Hospital, where we are refurbishing and replacing mechanical, electrical, and plumbing (MEP) systems in the central powerhouse, including the central steam, chilled water, and emergency power serving the facility's operating rooms and general campus.
Think of these posts as a three-part guide that explains our 3D scanning and modeling strategy to expedite our workflow and exceed client goals. First, we’ll give you techniques to scanning existing MEP sites using the Matterport Pro 2 Camera and Matterport Cloud.  The second post is chocked full of tips on importing Matterport 3D spaces into Autodesk Recap, where you’ll prepare your point cloud for modeling in Autodesk Revit.  The third post helps you transform MEP modeling with Matterport and Autodesk Revit. We also invite you to view our on-demand webinar on these topics.

Ready to get started?  Here’s how we do it: 

To provide Toronto Western Hospital with a record of the existing facility systems they needed, we used the Matterport Pro 2 camera to capture 3D scans of the mechanical and electrical rooms with enough detail for our team to reference in Autodesk Revit for modeling. 
Capture 3D scans of the mechanical & electrical facilities with the Pro2 Camera.
We documented systems at Toronto Western Hospital, scanning 17,500 square feet of the site

Choose the right 3D scanner

We use the Matterport Pro 2 camera based on affordability and value.  Our investment, including the Pro2 camera, iPad, hard case, three tripods, the Matterport Cloud subscription, and staff training time totaled $13,500. These combined expenses were less than the cost of a laser scanner alone, which retails around $20,000 or more. 
With the Matterport Cloud offerings ranging from rapid processing, access to 3D models and obj files, measurement toolkits, and the ability to document equipment information using Mattertag Posts, it serves as one of our primary collaboration platforms for our BIM specialists, engineers, contractors, and stakeholders. 

Key principles to improve scanning for MEP sites 

1. What the camera sees, is what you get

Verify each scan has a line-of-sight to the previous scan, approximately 8 feet (Note: the camera’s depth sensors have a range of .5 meters to 5 meters and require sufficient overlap between scans to stitch the point cloud and model together). This way, the camera uses the depth data, as well as the visual alignment tags from the previous scan, to identify the correct location of the next scan.  
Confirm the scanner has a ‘line-of-sight’ to the previous can, approximately 8 feet. 
Capturing every surface, high and low, ensures the data exists in your model.

2. Mechanical rooms require more scanning for greater accuracy

Model accurately by capturing more scans. Mechanical rooms are clustered with a lot of piping and ductwork. Therefore, we thoroughly scan all sides of a surface to capture highly reliable data. If you want to see an object in your BIM software, the camera needs to scan the area of interest in the field! Remember, redundancy in data is a good thing.
Scanning all sides of surfaces, particularly in clustered mechanical rooms, ensures that you're capturing highly reliable data for modeling.

3. Use LED lights for darker areas, like exhaust plenums

The Pro 2 camera uses a structured light sensor to deliver optimal results in low-light, as-built conditions.  For dark areas, like the inside of plenums, we find it is helpful to illuminate the space with portable LED lights.  
Illuminate dark areas, like the inside of exhaust plenums, with portable LED lights.

4. Align scans with April Tags

Improve the visual quality of the space you are scanning by using visual alignment markers, also known as AprilTags.  Tape AprilTags to flat vertical surfaces, like walls and equipment, so the camera can place the scan in the correct location.  This depth information fine-tunes alignment.
Align scans with April Tags
Tape April Tags to flat vertical surfaces, like walls and equipment,  so the camera can use depth information to fine-tune alignment. 

5. Plan your scans - then, scan your plans

Scan in a grid pattern of side-to-side, or back-and-forth. Later, this helps you navigate the 3D model with ease.
Plan your scans - then, scan your plans
Create a plan to scan in a grid pattern of side to side or back and forth.

6. Verify accuracy with the Matterport Capture App

Use the Matterport Capture App, verifying you’ve captured each scan location before proceeding to the next.  This helps ensure you’ve scanned each point accurately before leaving the site.

7. Transition tripods

Identify locations to change tripods, or switch to a higher elevation. Scan an area at a lower height for approximately 8 scans. Then, switch to the taller tripod, scanning that same area at a higher elevation.  Lastly, switch back to the smaller tripod and repeat the process. This ensures you’ve captured all the areas of interest for a mechanical site from top to bottom, no problem.

8. Adopt a buddy system to train new employees

Train new employees for success. Pair novices with someone experienced in using the camera for their first site scans. Following these easy scanning techniques ensures we captured the most reliable data for MEP projects. Ready for the next step? In part two of this post, we’ll explore how to import Matterport 3D spaces into Autodesk Recap to prepare your point cloud for BIM modeling in Autodesk Revit.
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