When the Hearst Tower was completed in 2006, it became the first office tower in New York City to be certified LEED Gold by the U.S. Green Building Council for both its core and shell as well as its interior fit out. In part, it garnered this distinction for its use of daylighting controls, which mitigate the amount of power used for electric lighting. And while the project's employment of this natural resource to achieve energy efficiency certainly is admirable, a closer examination of Hearst's systems reveals that its implementation conserved capital expenditures more so than electricity.
“Hearst took advantage of daylighting basically for a LEED point,” says Jackson Ning, principal of Kugler Ning Lighting Design, the firm responsible for the office tower's interior lighting scheme. “They evaluated it and decided that they wanted to have the green aspect and the LEED point, but it was cost prohibitive, so they did daylighting where they could.”
Of the tower's 46 floors, only two—the executive levels—employ daylight dimming systems at all perimeter spaces. The rest of the office floors were outfitted with daylight switching systems only on the east face, where there is a 5-foot-wide circulation corridor abutted by open workstations. Unlike dimming systems, which use sensors to adjust electric light levels in balance with the amount of natural ambient light, switching systems keep the electric lights off when sunlight is present, and turn them on when sunlight disappears.
One might assume that the east face was chosen for the switching system because it receives the greatest amount of daylight, but this was not the rationale. “The east side was the easiest one to implement,” Ning says. “They only had to run one extra circuit to those sensors.”
The electric lighting itself is as energy efficient as any commercial project these days. Most of the office floors utilize recessed 17W T8 high-quality color-rendering fluorescent fixtures. On the executive floors, where more art is on display, the fluorescent lamps were used in tandem with 37W halogen downlights. Hearst was able to use these more energy-intensive fixtures in the building by averaging the energy usage of all of the floors: “Workers get high-quality color rendering fluorescent lights, and executives get halogen art lighting and dimmers,” Ning explains. “When it's two floors versus the rest of the building, and you're saving 4,000W per floor, you get quite a trade-off.”
Of course, Hearst can't be entirely denounced for pinching pennies in its quest for sustainability. The company has gone further than most in the green direction. But the story told here does illuminate a particular failing of the LEED system: That the accumulation of points does not necessarily equal the smartest or more energy-efficient design.
Project Hearst Tower, New York
Client Hearst Corp., New York
Architect Foster + Partners, London
Associate Architect (base building) Adamson Architects, Toronto
Interior Architect (tenant floors) Gensler, New York
Lighting Designer (base building) George Sexton Associates, Washington, D.C.
Lighting Designer (tenant floors) Kugler Ning Lighting Design, New York
Watts per Square Foot 1.09 (offices)
Project Size 1 million square feet
Photographer Chuck Choi, Brooklyn, N.Y.
B-Light: 10W xenon wallwashing system at façade
Edison Price: 250W PAR38 tungsten halogen adjustable downlights at entrances; 150W PAR38 tungsten halogen wall grazer at lobby desk
Elliptipar: 150W metal halide uplights at atrium skylight; 1000W PAR64 tungsten halogen wallwasher at atrium core;250W T4 tungsten halogen uplight at main entrance
Erco: 500W PAR56 tungsten halogen adjustable downlights and wallwashers at lobby atrium skylights
Nulux: 250W PAR38 tungsten halogen linear slot/trough system at entrance lobby
We-ef: 100W T3 tungsten halogen accent luminaires at exterior façade
Zumtobel: T5HO linear fluorescent luminaire at main elevator lobby
Hearst office floors
A&L: Linear fluorescent strip covelights
Alkco: Undercabinet T8 linear fluorescent tasklights
Baldinger: Custom low-voltage decorative pendant on executive floors
Creative Light Source: Linear lighting system, and low-voltage MR16 tungsten halogen accent fi xture on executive floors
Danalite: Undercabinet low-voltage G4 halogen striplight on executive floors
Edison Price: Recessed compact fluorescent downlights, PAR56 wallwashers, low-voltage AR111 accent lights on executive floors
Leviton: 120V, 20-amp, 2-pole, 3-wire clockhanger receptacle for picture lights on executive floors
Litecontrol: Pendant-mounted continuous linear T8 fluorescent stacklight on office floors
Lucifer: MR16 downlights on executive floors
Lutron: Dimming ballasts
National Cathode: Cold cathode system for uplight cove on executive floors
Neoray: Linear T8 fluorescent fixtures at office floor restrooms
Osram Sylvania: Lamps throughout
Specialty Lighting: MR16 linear wallwashers and downlights on fitness level
Targetti: Low-voltage AR111 tungsten halogen accent fixture on executive floors
Tivoli: Cove-mounted low-voltage xenon quartz striplights on executive floors
Zumtobel: Ceiling-mounted T8 linear fluorescent luminaires on office floors