HVAC, Plumbing Prefabrication at its Best

For this look at commercial HVAC and plumbing prefabrication, we spoke with experts from one of the best in the business, TDIndustries of Dallas, Tex. Since 1946, TDIndustries has provided innovative engineering, construction and facilities services that optimize the performance of world-class mechanical systems which includes healthcare, hotels, schools, sports arenas, mission critical and industrial complexes.

TDIndustries has prefabrication and assembly facilities in its Texas cities, that are unrivaled by firms of equal size: Dallas, Austin, Fort Worth, Richardson, San Antonio, as well as Phoenix, Ariz.

This leading mechanical systems firm provided the HVAC duct and plumbing piping systems for the Atlanta Falcons Mercedes-Benz arena, and the Dallas Cowboys AT&T Stadium, now in their second and 10th years, respectively. Among TDIndustries’ most recent projects that integrated state of the art prefabrication assemblies, is the new, 14,000 seat Dickies Arena in Fort Worth, which will host rodeo shows and hockey and NCAA basketball. For the project, TD contributed to 41 miles of plumbing, 10 miles of HVAC work, and 14 miles of air duct in the building. 

Among other recent projects, TDIndustries has been commissioned by the Charles Schwab investment firm, for a new campus in Westlake, Texas. The project includes plumbing and mechanical systems installation for approximately one million square feet of office space between two phases of construction.

Dan Weir, senior project manager for the Charles Schwab project, and Ken Luong, project manager at Dickies Arena, provided insight into some of the basics of prefab, as well as advanced methods practiced regularly by TDIndustries.

The ideal prefabrication projects involve any piping or ductwork assembly that’s repeatable, such as throughout an office building or hospital, but it’s a strategy that can be scaled to the project. 

“Multiple floors or patient rooms that are basically identical are some of the best-case projects, as well as backflow prevention stations, pressure reducing stations, and plumbing batteries for restrooms. And for ductwork, we can prefab basically anything whether it’s repetitive or not. That’s what we do,” Weir said.

TDIndustries has always had some form of a sheet metal prefabrication shop. In 1980, it incorporated larger prefabrication projects, like plumbing batteries and central utility piping. When the company moved to its new Dallas headquarters in 1989, the manufacturing center was expanded, and now occupies 80,000 sq.ft.

Old Shop Keeps Up With What’s New
Ken Luong said prefabrication has always been a part of TDIndustries’ culture, and it has evolved through the years to keep in step with industry best practices. 

“We’ve always looked for additional things to prefabricate, and for ways we can be more efficient and productive; areas where we can build off of it ahead of time in a controlled environment rather than at a hectic jobsite, with many subcontractors working around you,” Luong said.

“As virtual design becomes more defined, and software becomes smarter, those two innovations continue to help us in the modeling and coordinating ahead of time. As far as In addition to new prefabrication opportunities, there are vendors and manufacturers that come to us with ideas to help us do our jobs easier,” Luong continued. “Whether it’s a new type of grooved system or fitting or material, these improvements are ongoing, because everyone wants to get better and find a better, less costly product.”

Helpful Design Programs
Among the new prefabrication innovations that have impressed Weir is ESTmep , by Autodesk, a relatively new program that is combined with a Building Information Modeling (BIM) model. 

“It’s one model and one database, so that every piece of pipe or duct have attributes recorded within that model, that tell you how much it’s worth and how much labor is required to install it,” Weir explains. “We’re right on the edge of implementing some really cool technology that enables us to take pieces of a model out and it will spit out exactly how long it should take to install a particular section of pipe or an entire area of ductwork. We’ve been working on this to help with tracking and improving both project planning and productivity. And under Autodesk there’s a multitude of software we utilize, including Revit in fabrication.” 

“There have been huge advances made in BIM over the past 10 years. We can now publish the model to where project foremen and superintendents in the field can pull up the model on iPad tablets. That’s not necessarily new, but each year, BIM becomes easier to view and use,” Luong said. 

TDIndustries uses Iris Prospect virtual reality software and HTC Vive viewing devices.

“Building Information Modeling allows us to virtually build the job in a 3D model, which greatly improves our capacity for fabrication,” said Wesley Baker, vice president of TDIndustries’ manufacturing and prefabrication facility. “The biggest key component is a ‘clash detection’ component which allows us to see all the different systems — fire protection/sprinkler, the large electrical conduit, ductwork, hydronic piping and plumbing systems and the structural systems — all in a 3D model. If they’re bumping into each other, the system will show us that. We can then remove those ‘clashes,’ which makes fabrication much more accurate and efficient.”

‘Plug-n-Play’ Plumbing
Luong added that plumbing batteries are probably the most common assembly that TD teams will prefabricate in the shop. 

“We have a lot of gang restrooms at Dickies Arena, so every single plumbing battery we created in the shop was shipped and set in place at the Arena. 

“The Dickies Arena’s central plant is one large prefabrication. We had all of the pipe, valve and fittings welded or coupled together in our shop before shipping it to the jobsite.”

TDIndustries fabricates and manufactures each and every piece of ductwork, it installs on any project, to the tune of five million pounds each year.

“The technology and equipment used to build ductwork assemblies has continued to evolve, and we’re using much more automated equipment in the shop, including CNC (computer numerical control) computerized manufacturing-driven equipment,” Baker said.

“We utilize a coil line, to fabricate straight runs of rectangular ductwork. This is an automated line that’s computer fed, driven by CNC. The information for the pieces of ductwork that are to be fabricated are fed directly to the machine controller, from our BIM model designs. It’s a very automated process. We do the same thing on the plasma tables, where we cut the patterns to make our fittings. We have an automated table to cut the duct liners to match the fittings.” 

Baker said a new trend called “multi-trade” fabrication is gaining in popularity. The method involves building a rack framework and installing the ductwork, chilled water piping, cable trays and conduit, all in 20-foot sections. “It’s the next future trend,” he said.

TDIndustries’ door is always open for visitors with
legitimate interest in advancing their own prefabrication skills. That includes manufacturers and contractors. On the day I  spoke with Baker, a team from Arizona was visiting. 

“We believe supporting prefabrication is the right thing to do. It will help us all with our labor shortage, with safety, and with meeting the demands of the industry. And, we can learn from each other,” he stated. A serious prefabrication shop requires a serious investment, one that small or mid-size contracting businesses find impossible to meet. Baker said less-capitalized firms will struggle with the investment that’s required for a quality prefab shop. 

“Then, once you build a facility like this, you must have consistent work. We have a seven-figure inventory right now, and much more invested in equipment. It makes sense for our operational size, but it will cost you if you don’t keep the lines running. I would say most companies outsource this until they become large enough. If you don’t have a coil line you can’t be competitive.”