Turner Construction Company is the largest general builder in the United States, with 5,000 employees and 2011 revenues of more than $8 billion. Turner’s Columbus, Ohio, office opened in 1964 and has been responsible for constructing some of the most notable buildings in Central Ohio including the Nationwide Arena, Greater Columbus Convention Center, The Ohio State University Stadium renovation, the new patient tower of Nationwide Children’s Hospital and the Hilton Columbus Downtown.
After 14 years in the northern suburb of Worthington, the company decided in 2010 to move its offices to downtown Columbus. “We wanted a headquarters presence close to our many Columbus clients,” said Kurt Smith, Turner’s regional preconstruction manager.
M+A Architects in Columbus was hired to design Turner’s new office, after evaluating several options in downtown Columbus. “We looked at three options,” said M+A Associate Ryan Ware. Of those, Turner decided on a 30,000-square-foot historic structure — a factory built in 1910 to manufacture mattress box springs. The old building is located just south of the Arena District, next to Huntington Park, home of the Columbus Clippers (Triple-A affiliate of the Cleveland Indians) and Nationwide Arena, home to the NHL’s Columbus Blue Jackets; both the stadium and the arena were projects completed by Turner.
Interior to Showcase Turner Expertise
For its new headquarters, Turner envisioned a space that would showcase its distinguished construction signature. The interior would be an open space showing off the fine old bones of the original building — the layered brick walls, the sturdy columns and trusses cut from 19th-century oaks, and the refinished old timber floors. The exposed ceilings would highlight the circuitry of lighting, HVAC linesets and indoor fan coils.
“Turner’s landlord tore down part of the building to make way for a parking lot, keeping the best-looking section of the old factory and leaving us with 13,000 square feet for our design work,” Ware said. “Turner then leveled the first floor slab, cut out several columns and removed three floor trusses to open up space for meeting rooms, and built a new entry feature. When it comes to aesthetics, Turner knows exactly what it wants.”
Selecting an Indoor Comfort System for a Century-old Building
For this major restoration, Turner wanted LEED® certification. “In our planning and design work, they asked us to aim for LEED Silver as a minimum,” said Ware.
To match this vision for exposed, natural interior spaces, Turner brought in Columbus-based Dynamix Engineering Ltd. Frank Hartley was the project manager for the Turner job: “When we first looked at this extraordinary interior, with very old conveyor belts running through the ceiling to the second floor, I thought to myself, forget all about plenums and space for mechanical rooms and systems.”
Hartley understood that he was dealing with an exceptional owner that understands the construction process. Dynamix needed to select the HVAC system carefully. Hartley sat down with Ryan Ware, Kurt Smith and Turner’s Mechanical Estimator Scott Blair to discuss the attributes of four possible systems from which to select:
1. A Variable Air Volume (VAV) system with hot water reheat
2. A VAV system with electrical reheat
3. Water-source heat pumps
4. Variable Refrigerant Flow (VRF) zoning systems
The Dynamix MEP team rated the benefits of each system. The Turner team selected the VRF zoning system from Mitsubishi Electric US Cooling & Heating Division, Suwanee, Ga.
Why VRF Systems Work So Well for Adaptive Reuse
In Hartley’s opinion, this VRF technology and equipment design are a perfect match for buildings constructed before air conditioning was invented. Because VRF zoning systems require little or no ductwork, Turner would avoid the huge energy loss associated with central forced-air systems. Up to 30 percent of the energy in ducted systems is lost in the ductwork itself, through leaks and other inefficiencies. With a VRF zoning system, the compact compressors and components can be installed in smaller indoor and outdoor spaces. These systems require less piping and duct space. Because the VRF zoning system uses smaller VRF refrigerant piping, it gives back space in the form of higher ceilings.
“As a design engineer, I felt this VRF zoning system was a great match for Turner’s aesthetic goal of keeping the interior spaces’ natural look of brick and timber,” Hartley said. “In this old factory, there was no option for the typical mechanical room, and with this Mitsubishi Electric system there was no need. The ingenious central controller, about the size of a large suitcase, can be conveniently tucked away in a small closet. The outdoor units are small and lightweight, and are easily positioned on the roof without needing added support.”
Hartley went on to explain that VRF zoning systems are 31 percent lighter than chilled-water systems, making them easier to handle and less expensive to install.
“Turner managers were especially impressed with the sound attenuation of the interior units and the connecting piping and wiring,” Hartley continued. “They were surprised that someone could stand a few feet beneath an indoor unit and not hear it operating. The contractor did a beautiful job of installing the insulated indoor units, piping and wiring, and Turner liked the clean, uncovered weaving of the exposed VRF zoning system hardware. Next to the wooden trusses and interior columns, it was attractive.”
VRF for LEED Certification
“The selection of this VRF zoning system made me a believer,” said Blair. “At Turner, we are recognized for our pioneering work in the green building movement. The thing that makes me happy is we proved that it is possible to bring century-old spaces up to 21st-century standards. This state-of-the-art VRF technology is ideal for an office environment.”
The installation of the VRF zoning system allowed Turner to pursue and achieve LEED Gold certification.