Salt Lake City/City Creek Center
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Urban Renewal Utah-Style Snowmelt in Downtown Salt Lake City By John Vastyan here’s a new and shimmering upscale tourism and retail variety of water features developed by Property Reserve, Inc., destination in the heart of Salt Lake City that’s won the the commercial real estate division of the Church of Latter Day attention of city planners worldwide. Some call it urban Saints, and managed by Taubman Company and City Creek renewal on steroids. Others regard it as just one more reserve, Inc. Textension of the buoyant and optimistic resource that Utah is. The center encompasses nearly 20 acres of downtown Salt Lake When Salt Lake City planners looked at many options for a revital- City and is part of an estimated $5 billion sustainable design proj- ization of their downtown area, they wanted ambitious ideas. Today, ect to revitalize the downtown area. the mixed-use City Creek Center is the realization of that dream. City Creek Center is an 800,000 sq. ft. space, covering two The $1.5 billion development is an upscale, open-air shop- entire city blocks that now serves as the economic driver for the ping center that includes office and residential buildings and a city’s Renaissance. 30 JANUARY 2014 | REEVES JOURNAL RADIANT BONANZA Smart by Design At City Creek Center, mechanical sys- tems were integrated smartly, by design. The mechanical plan was put into action by the 250-person firm, CCI Mechani- cal, Inc., based in Salt Lake City. The firm (with revenues of about $60 million annu- ally) is involved in the design, installation, and maintenance of mechanical systems for commercial and industrial facilities throughout the Western United States. To give you a sense of the enormity of the project, all exterior walkways, stairs and common areas in both of the project’s city blocks feature snowmelt systems. These areas cozy up to the large open or enclosed space of both malls, fully served with in- floor heating and cooling. Planners set out to provide environmen- tal control and comfort for two 160,000 sq. ft. retail mall spaces, each connected by an enclosed, environmentally-controlled sky bridge. Each of the malls can be opened to the elements and fresh air, or closed to provide CCI Mechanical supervisor Seth Roth said, "If I never see another zip tie, I won't mind at all" after his optimal comfort inside, thanks to the auto- crews used the most cautious means of connecting PEX tubing to rewire in the upper levels of the malls matically retractable roof and wall systems. at City Creek Center. Yet, as substantial as the mechani- to 60 CCI craftsmen at City Creek Center. According to CCI’s Nathan Gover, CCI cal infrastructure is, a key attribute of the “There are three large closed-circuit fluid HVAC technician, who supervises all ongo- plan was the effort to simplify all facets coolers and two smaller open-circuit cool- ing mechanical system service and main- of the design so that the overall system’s ing towers, all raised on eight-foot pedes- tenance needs at City Creek, the open-cir- many mechanical parts n’ pieces wouldn’t tals on a rooftop – with raised work plat- cuit “UT” Evapco cooling towers are of an be strewn across the two city-block-sized forms for access to the cooling towers [also induced-draft, counter-flow design. One is space. Fluid systems integrate immense supplied by Evapco] – a smart arrange- rated at 1,400 gpm; the other at 2,800 gpm; heating and cooling functions, connected ment that provides space for mechanical both with 90 F in/80 F out and 65 F wet through the efficient exchange of BTUs at systems below them, including a bank of bulb. They serve the heat rejection needs for many levels. large pumps.” five, 280-ton Daikin Magnitude magnetic Though there are thousands of inter- “The low-noise Evapco cooling tow- bearing centrifugal chillers. connected components, and many key ers were chosen for their suitability for an The key challenge in connecting these mechanical stations, there are arguably urban environment,” said Roger Johnson, large systems was how to orchestrate the two main elements of the vast mechani- sales engineer for Salt Lake City-based movement of fluids between the cooling cal systems at City Creek Center. First, manufacturer’s rep firm, TMS, Inc. towers, water-sourced heat pumps and the there’s the evaporative cooling towers and The closed-circuit “ESWA” induced- fluid cooler heat exchangers. the water-sourced heat pumps connected draft hybrid cooling towers – connected Five Taco “TA” horizontal split-case, 60 to them. And there’s the interior, in-slab to large water-to-water heat pump systems HP pumps rated at 2,026 gpm at 75 head/FT radiant heating and cooling systems, and – have stainless steel heat exchangers to serve the fluid coolers and water source heat much larger exterior areas with snow- reject heat. “The cold water basins are also pump system. Five more TA’s – sized at 25 melting capability. made of stainless for durability,” added HP and 840 gpm at 75 head/FT – and four Johnson. “Two of closed-circuit towers are “FI” base-mounted, end-suction pumps, Evap/Condenser System rated at 4,052 gmp [w/40 percent glycol, each rated at 125 HP and 2,375 gpm at 130 “The cooling tower arrangement is unique,” 90 degrees F in/80 F out with 65 F entering head/FT – serve the condenser water loop. said CCI’s Seth Roth who, for 36 months, wet bulb], and one is a 2,038 gpm system,” “The TA pumps can be mounted hori- supervised and coordinated the work of up Johnson added. zontally, so this was especially useful for WWW.REEVESJOURNAL.COM 31 RADIANT BONANZA More than 102,000 lineal feet of 5/8" Watts Radiant PEX+ tubing was installed in throughout both of the City Creek Center malls, providing warmth in the winter and cooling in the summer. installation in the space that was created Center are five Watts backflow assemblies. There All Things Radiant under the cooling towers,” continued John- are three three-inch 909 reduced pressure prin- CCI craftsmen installed 18.5miles of son. “The FI pumps were installed inside ciple assemblies (“RPZ”s), one each to serve ¾-inch Watts Radiant PEX+ tubing for the building.” makeup water for the cooling towers, the glycol the 84,365 sq. ft. snow melt systems alone. All of the large, multi-horsepower side of the water-source heat pump condenser According to Gover, there’s another 102,600 pumps connected to the heating and chilled loop, and another connected to the makeup lineal feet of Watts Radiant PEX+ (5/8-inch water systems are connected to variable fre- water for the water-source heat pumps. in size) to circulate fluids within the 25 quency drives. Also, there are two two-inch 909 RPZs. indoor radiant heating and cooling zones For the radiant and snowmelt systems, One serves the makeup water for the boil- (for a total of 47,656 sq. ft.). the VFDs modulate flow to track heating or ers; the other is connected to makeup water “We chose Watts Radiant tubing for the snowmelting demand precisely as ambient for the chillers. project for a couple of reasons,” said CCI’s temperatures change. On the cooling side, The heat exchanger-separated glycol/ Roth. “The design reports or tubing layouts the VFDs adjust flow based on the need to water mix circulates between the water- provided by [the Salt Lake City-based rep transport and reject heat. Naturally, during source heat pumps and the radiant tubing firm] Lundquist Sales are very detailed and the evening hours, as the load diminishes, below the retail stores, lobbies, and walk- accurate. Their service is excellent. We also flow and electricity usage are reduced. ways. Essentially, this circulatory system appreciate the 1,200-foor rolls of tubing; Condenser water loop fluid cooler conditions the huge spaces in both of the only a few suppliers offer that. At City Creek, spray pumps were not connected to VFDs controlled-environment malls. And if the we had the giant rolls on wheeled uncoilers because the cooling towers require a set, expansive snowmelt system is thrown in for and simply cut off four 300-foot rolls from consistent flow during operation to avoid good measure – involving about 30 acres of each. We could cover a lot of ground quickly. fouling of the evaporative media. space through tubing embedded in the con- The tubing is easy to work with and reliable.” Protecting the domestic water supplies crete slabs and under pavers – the job takes In “Block 75,” CCI technicians installed in the main mechanical areas at City Creek on extraterrestrial proportions. 15 snowmelt zones, and 12 radiant heating 32 JANUARY 2014 | REEVES JOURNAL RADIANT BONANZA or cooling zones. In “Block 76,” 13 snowmelt zones and 13 radiant zones were installed. Each zone is served with a tekmar 090 snow and ice sensor; each is nestled into an 091 socket. The 090 is an in-ground sensor which automatically detects snow or ice on solid exterior surfaces. The sensors are set up to activate the vast snowmelt systems when snow or ice is present, while also providing slab temperature feedback to the control. CCI installers also used 2,400 lineal feet of 5/8-inch Onix EPDM synthetic rubber tubing to provide snowmelting capability for several exterior stairways. “CCI requested that they be allowed to buy the tubing specifically for the stair- ways because of its superb flexibility – a valuable attribute when doing stairs and risers,” said Mike Lundquist, president of Lundquist Sales, Inc.