“Historically, these supplemental access structures don’t seem to get as much attention as the main facilities they support. A great deal of coordination has to happen between many different trades to ensure all of the project needs are met,” says Althouse. “Ultimately, these structures require careful consideration too.”
Keeping It Cool
Application: Cooling Towers
Mathu Solo, president of Tower Tech in Oklahoma City, calls the company an American success story. Founder Harold Curtis graduated from high school and began working as a field laborer in cooling tower service, repair and rebuilds. Cooling towers are a simple, but critical, piece of equipment that serve as a heat exchanger. Hot water comes into the tower from an industrial process, mixes with air to lower the temperature, then the cold water circulates back into the industrial process.
“Our founder soon realized that all the problems with cooling towers, no matter who manufactured them, had the same main issue – the construction materials,” says Solo. In the late 1980s, most cooling towers were made from wood, which degraded over time. So, Curtis set out to design a better tower. In 1992, Tower Tech marketed the first GFRP cooling tower made via hand lay-up.
“FRP was non-corrosive, but hand lay-up was very time-consuming and we couldn’t maintain strict tolerances, which are critical to create a complete wet-dry barrier,” says Solo. “To grow our business and increase production capacity, we had to be a lot more efficient.”
The company considered several other manufacturing processes, including vacuum infusion and rotational molding, and moved to pultrusion in 1994 because of the strength and durability the process provides. In the early 2000s, Creative Composites Group (CCG) became its sole provider of pultruded profiles. Creative Pultrusions, a subsidiary of CCG’s holding company, purchased Tower Tech in 2017.
All of the structural components of the cooling towers are made from GFRP, while the motor, fan supports and fasteners are stainless steel. Some components, such as top and corner caps, are molded. There are seven custom pultruded profiles, including a 12 x 12-foot box to house the fans and a bottom basin panel with a channel for water to run through. In addition, the cooling towers incorporate four standard shapes internally for mounting brackets, dividers and structural bracing.
“Cooling towers typically operate outside, so they have to be certified for structural, wind and seismic loads,” says Solo. “It was critical to have the strongest components possible.” The components also need to be corrosion and UV resistant. The ply layout for the pultruded shapes consists of a 10-mil polyester surface veil, continuous filament mat, stitched fabrics and unidirectional fiber.
Collaboration between Tower Tech and CCG is vital.
“We are a cooling tower company, not a fiberglass company,” says Solo. “It’s been beneficial having a partner that is always ahead of what’s going on in the industry and looking at new technologies to improve their processes.” For instance, CCG and Tower Tech collaborated on storm-hardening technology, developing StrongStorm® modular cooling towers rated for 200 mph winds.
With more than 5,000 installations worldwide, Tower Tech is the only company of its size to offer pultruded cooling towers, says Solo. That puts it in a good position in a market valued at $3.82 billion in 2021, according to a report by Fortune Business Insights. The report predicts the cooling tower market will grow to $5.29 billion by 2029.
“We are without a doubt the most advanced product on the market, and we don’t sell on price,” says Solo. “We sell on the added value of our FRP design, and the payback in terms of operational savings. That’s where our success story starts.”
Enabling Energy Efficiency
Vaisala, a Finnish company specializing in industrial measurement equipment, opened a 38,000-square-foot North American headquarters in Louisville, Colo., in 2020. Designed by OZ Architecture, the cross-laminated, timber hybrid structure is designed for net-zero functionality. Curtainwalls featuring pultruded composite pressure plates help contribute to the company’s energy efficiency objectives.
The two-story building includes more than 3,400 square feet of curtainwall enclosing a daylit atrium and reception area. The curtainwall uses a 2.5-inch-wide profile system that integrates Deceuninck’s Innergy AP® thermal pressure plates, which were customized by its customer Tubelite Inc for Vaisala. Combined with warm edge spacers, the GFRP thermal pressure plates achieve a system U-Factor of 0.32 and 7,500K psi flexural modulus. (U-Factor refers to the energy efficiency of window systems, with lower U-Factors providing better insulation.)
Deceuninck North America’s main line of business is PVC extrusion. A decade ago, the company began designing a window system with an eye on energy performance requirements.
“With PVC window and door systems, metal reinforcements are commonly used inside certain system parts to add strength, and this metal naturally short circuits the thermal performance,” says Greg Koch, vice president of sales and marketing for Deceuninck North America in Monroe, Ohio. “We started looking at options to replace the metal reinforcement, and our team came up with a fiber-reinforced polymer material that is almost as strong as aluminum and has the thermal properties of glass.”
The company markets its thermal reinforcements under the brand name Innergy – a combination of ‘in’ (inside products) and ‘energy.’ A few years ago, Deceuninck branched into other building envelope products, including thermal pressure plates for curtain walls and Z-girts, calling the product line Innergy AP – architectural products.
Manufacturing thermal pressure plates was challenging at the outset.
“This is a really dynamic material. Even though it’s made from polyurethane, it’s 80% glass fiber,” says Koch. “And processing glass is very abrasive.” Deceuninck designs proprietary pultrusion tools and processes to overcome the abrasion.
Koch says composites are gaining traction in architecture, and Deceuninck has just begun to infiltrate the building envelope end of its business.
“There are so many different pultruded shapes we are looking at and working to design. But you can’t just put in some glass fiber and polyurethane and pull it through the machine,” he says. “Various shapes are needed to achieve different levels of performance, so designing for that may call for additional materials, such as mats or veils.”
While Deceuninck expands its reach in pultruded products, Koch encourages others in the industry to pursue innovations and share their stories, too.
“We wanted to develop something different and come up with an option to aluminum, and it turned into something very cool,” says Koch.
Susan Keen Flynn is managing editor of Composites Manufacturing magazine. Email comments to email@example.com.