iWorx® Building Management: Case Study in Real World Technology Tanque Verde Apartments RETROFIT CONSTRUCTION, TUSCON, AZ -2- iWorx® Building Management: Case Study in Real World Technology Tucson Commercial Firm Keeps it all In-House When the owners of Tanque Verde Apartments in Tucson decided to upgrade mechanical systems, they made it clear that they wanted a dramatic shift from old to new. Until recently, the 15 acre, 428-unit complex has met the heating and cooling needs of the tenants, but with little regard for the amount of energy consumed in the process. When the apartments were built 30 years ago, energy efficiency wasn’t exactly the main focus. After all, the price for gas and electricity was a fraction of today’s rate. At Tanque Verde, an enormous At the source district system heated and cooled “We have 20 technicians,” said Mo all the apartments. Last year, the Forrey, owner of Oracle Control hydronic system began leaking Systems, Inc. (OCSI). “Though underground. Tenants com- the name suggests it, we’re not plained about lack of controllabil- just a controls company. We’re ity while repair bills accumulated. a start-to-finish, design-build, Making matters worse, the equip- commercially-focused mechanical ment was outdated, bandaged contracting firm.” and in desperate need of replace- To meet Scotia Group’s needs, ment. OCSI designed and installed all Scotia Group Management, LLC, is new hydronic heating and cool- an Arizona-based firm that super- ing equipment, solar-thermal vises 25 large apartment com- DHW system, modular building plexes in the Phoenix and Tucson automation controls, and large areas, including Tanque Verde photovoltaic arrays to bring Apartments. Rob Aronoff, owner Tanque Verde out of the mechani- of Scotia, is actively involved with cal Stone Age. all projects going on at his facili- Between March and December ties, so when a retrofit was first of 2011, OCSI crews tore out and considered at Tanque Verde, he replaced boilers, chillers, and was quick to embrace the idea. underground hydronic lines. The The Tanque Verde Apartment complex covers 15 acres and includes 428-units. When it comes to overhauling two original mechanical build- colossal mechanical systems, this ings were kept; the smaller on wasn’t Scotia Group’s first rodeo. the north side of the complex, Same goes for their mechanical and the larger on the south. Since contractor. Oracle Control Sys- none of the tenants could be tems and Scotia Group have been displaced, OCSI installed parallel working together for more than piping throughout the property 15 years. while keeping the existing system -3- iWorx® Building Management: Case Study in Real World Technology control module (BLMC). Each module can monitor and control up to four boilers, as long as the boilers are serving a common load. Six years ago, Trane 30HXC water-cooled screw chillers were installed in both of the mechani- cal buildings. When it came time for the retrofit, both units were on-line. Temporary chillers, boil- two Carrier chillers, each with a ers and piping were employed to cooling capacity of 160 tons. The maintain service. south side of the complex calls for 840 GPM of 44˚F water. Outside, “We removed an old Cleaver the cooling towers stand nearly as Brooks Model 4 boiler from the high as the building itself. south mechanical building,” said Forrey. “It was probably the last On the north side of the complex, one in Tucson!” Like the sur- a similar approach was used. The rounding apartment buildings, mechanical building had a large the 1,700 square-foot south atmospheric boiler and three in good shape and were kept in mechanical building simulates vertical water heaters for DHW, all service. Each of the three chillers traditional adobe architecture. of which were removed. Now the on the job are remotely moni- building houses two, 1,000 MBH tored and controlled by an iWorx The flat roof and stucco exterior gas boilers and one large chiller. chiller control (CCU2). This allows are deceiving. The mechanical Hydronic demands for the smaller maintenance or service personnel building now houses two, 2,000 system are 140 GPM on the heat- to observe or make changes from MBH, gas-fired boilers that supply ing side, and 280 GPM for cooling. the local control interface within the 420 GPM at 120°F demand. the mechanical building or from In addition to the heating equip- Each mechanical building is any web-enabled device. ment, the building includes outfitted with a Taco iWorx boiler -4- iWorx® Building Management: Case Study in Real World Technology Distribution “We’ve re-piped several prop- erties in the dead of summer without displacing tenants,” said Forrey. “Once the new piping was live, we could switch over four apartments at a time with mini- mal interruption to tenants.” System fluids leave the mechani- cal rooms in a six-inch, super-in- sulated pipe. At their shop, OCSI personnel made the large mani- folds for the job. Two 25-horse- power Taco frame-mounted end-suction pumps provide flow in each mechanical room. The system also incorporates high- The 428 apartments (studios, one nine return lines. One return velocity 4900 series air and dirt and two-bedroom units) use fan pump per mechanical building separators. coils that range from 400 to 1,000 uses balancing valves to keep Heating and cooling distribu- CFM. Once inside the building, fluid moving in multiple return tion piping is shared. Each zone water passes through what Forrey lines. includes three or four apartment refers to as ‘wild coils.’ Controls buildings. The zones are piped “There’s no control structure on “As we’ve done with our other in a home-run configuration the water lines to the fan coils,” iWorx projects, we monitor this from the mechanical building to said Forrey. “Water flows through facility,” said Forrey. “Since we isolation valves at each building. the coil at all times. If the tenant know the job inside-out, and we During installation the new pipe wants heating or cooling, they have the service contract, there’s paralleled the old pipe, but they simply turn the fan on.” really no reason for anyone else parted ways at the building’s to keep an eye on it. We watch foundation. Each apartment has a thermal everything back at the office.” switch to change thermostat to While the old pipe entered heating or cooling. “We used to be a rep for a apartment buildings from under- controls manufacturer and, as a ground and came up through the Domestic hot water uses a similar sub-contractor, we’d install their floors, the new pipe rises up to piping layout, but with more products on other jobs,” said For- the roof, and supplies the fan coil zones. DHW is supplied to seven rey. “Now we only do controls for units from above. This unique ap- zones; each three-inch line is our jobs. We’ve settled on Taco’s proach allowed OCSI to keep the connected to a large solar-heated iWorx controls because they’re original system in play for as long buffer tank. Because of building easy to install and require minimal as possible. layouts, the DHW system uses -5- iWorx® Building Management: Case Study in Real World Technology programming. There was virtu- easily-scalable, open-protocol nated, and installation costs drop ally no learning curve when we building management, monitor- significantly. started using the product. We’ve ing and control system designed “Once a controller is wired into been looking for specifically for the system, you just push a but- a controls plat- the commercial “ Not only is iWorx a ton, and it identifies itself on the form just like it.” market. great product, but network,” continued Polansky. “Not only is it a our rep stands “What makes “No control sequences to write; behind it entirely”. great product, iWorx different no website to build.” but our rep from other sys- — Mo Forrey An ALM2 alarm module in each stands behind it Owner of OSCI tems,” explains mechanical room monitors all entirely,” said For- Tom Polansky, key facets of the mechanical rey. “Brian Traub, at Flow Products technical service engineer at Taco, systems. OCSI is alerted by email is great to work with. He was “is that you don’t need special if there’s a problem with one of very enthusiastic about the new tools, software or computers to their systems. If the chilled water controls platform.” do the installation or commis- loop starts running a little warm, sioning.” Once wired, programs Traub is the president of Tempe, OCSI techs can get to the job to are resident in the controller. By AZ-based Flow Products. The solve a problem before tenants or manipulating control parameters firm represents a wide range of the building owner even become for the specific HVAC equipment HVAC equipment, and helped aware of it. on the LCI (Local Control Inter- throughout the design phase. face), engineering time is elimi- The iWorx system is a web-based, The Local Controller Interface has resident programs so engineering time is eliminated and installation costs drop significantly. -6- iWorx® Building Management: Case Study in Real World Technology The BTU3 controller monitors the BTUs produced by two solar thermal arrays. The two solar-thermal arrays are “By doing our engineering, hours. We usually come in 50 to always under the watchful eye controls work, and fabrication 60 percent below replacement of a BTU3 module. This device in-house, we keep our guys busy, cost, and have them running the monitors BTUs produced by the and get a better product in the same day.