Largest Pedestrian Bridge in Utah Will get Radiant Snowmelt System

The brand new 1,000-foot pedestrian bridge connecting college students to the Utah Valley College (UVU) campus was in want of a constant, dependable snow and ice removing resolution that didn’t require salting or sanding surfaces or transferring gear throughout the construction. Aron Frailey, proprietor and chief mechanical engineer of Thermal Engineering, LLC, has a long time of expertise in hydronic radiant snow-melt programs, however he had by no means designed or put in a system for a 15-foot-wide (4.6-meter-wide) elevated expanse, suspended as much as 35 ft (10.7 m) within the air.

To satisfy the problem, Frailey wanted piping options that may be sturdy sufficient for the tough circumstances, but in addition viable for his building crew. As a longtime buyer, Frailey regarded to REHAU for the snow-melt loops of PEX piping embedded within the concrete pathway, deciding on RAUPEX® O₂ barrier pipe for the job. As the primary element in hydronic programs, this PEXa piping gives long-term power, enhanced temperature capabilities and an additional layer of safety towards oxygen permeability with its co-extruded ethylene-vinyl alcohol (EVOH) oxygen diffusion barrier.

“We’ve used REHAU pipe for a very long time and by no means had any points. It’s like second nature,” he stated. “We all know it. We all know what to anticipate from it. We have now had a lot technical assist and expertise with REHAU.”

Design Components

Whereas Frailey has a few years of profitable tasks utilizing PEX for each radiant heating and snow and ice melting (SIM), this was Thermal Engineering’s first main venture utilizing polymer piping for distribution piping to the SIM loops, attributable to its huge advantages in comparison with working with metal pipe on this elevated software.

He collaborated with REHAU producers’ rep Rocky Mountain Built-in Options, Inc. (RMIS) on the venture design and materials choice. Moreover, engineering consulting firm WSP supplied design experience in session with the Utah Division of Transportation for the high-efficiency boiler plant and management programs serving the bridge, together with NTI Hearth Tube Giants (FTG) Boilers with a 2.2 million Btu capability, Grundfos CR pumps and a Tekmar 680 management.

The design used 34,500 ft (10,516 m) of 5/8 in. REHAU RAUPEX O₂ barrier PEX piping for the SIM loops. The PEX piping was mounted on to the 6 x 6 bridge deck rebar at 6 in (16 cm) on-center spacing earlier than being encased inside concrete. The piping was related to pre-fabricated manifolds that have been put in throughout the bridge deck and accessible by way of entry panels. The manifolds are provided with a heated antifreeze resolution by 1,900 ft (579 m) of two 1/2 to 4 in (6 1/2 to 11 cm) provide and return piping.

Frailey helped design the manifolds and oversaw their modification and placement throughout set up. In complete, Frailey fabricated seven 2 in (6 cm) {custom} copper manifold vaults to deal with distribution piping, utilizing F1960 fittings for connections to SIM loops.

Distinctive Challenges

For the reason that bridge has open sides subjected to blowing snow within the wintertime, the homeowners needed a heated concrete walkway to extend pedestrian security. “Having a completely melted walkway throughout the bridge was a venture requirement for UVU and the Utah Division of Transportation,” defined Ben Weerts, PE, representing WSP because the lead mechanical engineer for the venture. “It was essential to supply the general public with protected passage throughout the a number of lanes of I-15 and railroad tracks all through all the yr, together with the center of winter.”

The primary problem with the UVU bridge venture was the construction’s peak, spanning an interstate freeway. For hydronic provide and return piping, the unique specification known as for 4 in (11 cm) metal pipe. Attributable to its heavy weight, metal piping would require quite a few installers, heavy lifts and a number of welding. Frailey was involved about jobsite security of welding that prime off the bottom below the bridge deck.

Moreover, Frailey was involved concerning the perform of metal piping by way of its lack of ability to face up to bridge motion with temperature adjustments and ease of corrosion. After investigating piping alternate options, Frailey discovered that PP-RCT offered advantages the place metal piping fell brief. PP-RCT supplied a better set up with its mild weight, eradicated open-flame welding, might flex with the bridge’s motion and will stand up to the salt and magnesium chloride Utah makes use of to soften snow and ice on its highways. 

The power of PP-RCT to maneuver in unison with the bridge was one of many greatest promoting factors for Frailey. In line with him, “The construction is meant to maneuver in each course on a regular basis—left to proper, backwards and forwards, up and down,” he stated. “I used to be involved concerning the joint integrity of a metal piping system with all that motion, and I actually preferred the pliability of PP-RCT to deal with it.”

The radiant loops have been additionally designed with the motion of the bridge in thoughts. “We designed to match the way in which they needed to pour the bridge, so the radiant loops would by no means cross an growth joint. Every loop connects to its personal custom-built manifold within the slab of that part of the bridge, which then connects to the provision and return piping. REHAU provided {custom} 400 ft (183 m) coil lengths to attenuate the variety of circuits and optimize the radiant design,” defined Frailey.

Making Historical past

Upon completion, the UVU bridge venture turned Utah’s largest pedestrian bridge. The 15-foot-wide bridge spans greater than 1,000 ft (greater than three soccer fields) throughout I-15. Elevators on all sides of the bridge accommodate pedestrians, bikes and scooters. It’s estimated that 4,000 to five,000 college students will use the pedestrian bridge day by day.

A pedestrian bridge has been a part of the UVU grasp plan since 1993 as a means to supply entry between the Intermodal Heart in Orem and the UVU campus. Funding for the $30.7 million bridge was authorized in 2016 and building started in 2018. The UVU Bridge formally opened in February 2021.

Because the SIM system will function by its first full winter within the 2021-2022 season, Weerts is assured about its future efficiency. “In-slab hydronic snow-melt programs are some of the environment friendly and efficient strategies for sustaining snow-free surfaces,” Weerts stated.

The SIM system is a testomony to the teamwork between Thermal Engineering, WSP and REHAU producers’ rep RMIS. Because of their collaboration and dedication to high quality, college students can cross the bridge safely all year long with out the necessity for UVU to rearrange snow removing companies. Frailey concluded, “This bridge is a really efficient software for hydronic SIM. I can’t think about some other sensible means of eradicating the snow, and it operates very affordably as nicely.”

Undertaking at a Look

Undertaking: Utah Valley College (UVU) Pedestrian Bridge, Orem, UT

Sort of building: Infrastructure for academic facility, opened 2021

Scope of venture: 15,000 sq ft (1,394 sq m) of heated walkways at 15 ft (5 m) vast and almost 1,000 ft (305 m) lengthy

Normal contractor: Kraemer North America

Civil and mechanical engineer: WSP USA Inc.

Mechanical contractor: Thermal Engineering, LLC

Producer’s rep: Rocky Mountain Built-in Options, Inc. (RMIS)

Distributor: Mountainland Provide

REHAU programs used: Snow and ice melting, RAUPEX^® O₂ barrier pipe