The Time Warner Center completed construction in 2003. The building’s original booster pumps were constant speed, horizontal split case pumps that provided water to potable fixtures. Over the course of 10 years, the building paid high maintenance costs due to frequent replacement of the Pressure Reducing Valves (PRVs) on the discharge of the pumps. A new federal code requirement, NSF/ANSI 61, also called for different materials of construction to reduce lead in drinking water.
The engineering team recommended QuantumFlo’s WisperFlo variable speed booster pump package. The WisperFlo does not use a PRV, but rather a variable frequency drive (VFD) and control logic to maintain system pressure based on demand. A submersible vertical multistage pump type is used on the WisperFlo instead of a horizontal split case type. The submersible pump is surrounded by water within a stainless steel canister.
Providing the same output, the motor horsepower required was decreased from 60HP to 30HP. The lower horsepower, variable speed capability, and removal of the PRV will allow for substantial operating and maintenance savings. The new booster system complies with NSF/ANSI 61 and the submersible pump design also greatly reduced the noise that was formerly caused by the old pumps.
Jaga customized fin tube elements to meet project demands
Design specifications required the museum’s viewing area, with its floor-to-ceiling glass windows, to maintain clear views onto the memorial site and its fountains. Given the space constraint, we needed to devise customized piping size units for arrangement within the concrete sub-floor. Heating such a space without baseboard on the wall informed this particular complexity.
Wales-Darby, Inc. recommended that the engineer, Buro Happold, work with Jaga mini canal trench type in-floor fin tube radiators. Functionally, this trench heating method design allows easy access for cleaning and maintenance. Aesthetically, the sub-floor placement allows for a grill to complement the interior design.
The installation of customized Jaga fin tube radiators along the perimeter prevents condensation on the floor-to-ceiling windows and assures unobstructed views of the memorial. Utilizing low-temperature water, the system also provides energy efficiency and reduced operating costs.
For this ground-up new construction, the client requested a high-efficiency boiler system with more than 90% energy efficiency. With design plans requiring the boiler room to reside in a tight space, our particular challenge was to provide an extremely efficient system within the room’s constraints.
Wales-Darby, Inc. worked with GKA to find the most efficient boiler system. We chose three HydroTherm KN-20 modular condensing boilers, with each boiler producing two million BTUs per hour. For ease of service, we installed a Taco 4900 high velocity air separator with PALL ring technology and detachable covers to remove air, dirt and microbubbles from the system.
The system maintains a small footprint, with all maintenance conducted from the front so that the boilers can be placed tightly. Every pump has a standby, firing in parallel to ramp up and slow down in concert, based on the heating demand. The boilers modulate based on outdoor air temperature to meet the current heating demands of the building—including 177 rooms and suites, kitchen facilities and a rooftop bar—and increasing efficiency of the system to heat water to a certain temperature, which is then supplied to terminal units throughout the hotel.
Architectural plans called for a 46-story Diagrid tower to rise above the original six-story Landmark site of the Hearst Corporation headquarters in Midtown Manhattan. Air conditioning the dramatic six-story lobby—with its 70-foot-high ceiling—provided a particular set of challenges.
Concrete flooring and displacement ventilation perfectly conduct the radiant heating and cooling system—a matrix of water circulating through embedded pipes that removes heat from sunlight coming through the windows. With energy efficiency in mind, Uponor employed a stepped water fountain on both sides of the central escalators to cool and dehumidify the lobby space.
The lobby’s radiant cooling system—the first of its kind in the United States for a commercial high rise—maintains year-round comfort, with no condensation on the floor. As the first “green” high-rise in New York City, Hearst Tower uses 25% less energy than the minimum requirements of prevailing codes for buildings. The building also received the city’s first U.S. Green Building Council’s LEED Gold rating.