CHALLENGE Far from the sterile environment of a conventional supermarket, the inviting atmosphere of the Whole Foods Markets encourages shoppers to explore and linger. While retailers favor bright lights to lure customers to displays, general concerns over the use of traditional lamps, specifically the ultraviolet and infrared wavelengths they emit, have prompted stores to rethink their lighting approach. Owing to this and other issues like energy usage, the Whole Foods Markets' lighting standards, while store specific, 'have been in continual development,' says Mike O'Leary, principal at CTA, the architecture and engineering firm that has worked with the store for the past five years. The defining challenge found in developing a lighting concept for the new 80,000-square-foot landmark store in Austin, Texas, was efficiency.
Architectural and lighting SOLUTION In keeping with the personal yet theatrical ambiance common to all Whole Foods Markets, the design team (Whole Foods Market consruction, decor, and department specialists; CTA; Lighting Design Lab; Legacy Lighting; and Koncept Lighting) used a variety of fixtures to complement each aspect of the store. Brightly colored walls and inward curving departments with theme-park-like monikers-Fifth Street Seafood, Candy Island, and Lamar Street Greens-provided opportunities to transition from heavy use of incandescent sources to ceramic metal halide on track and other specialty fixtures, like fiber optics and case-specific lamps.
To maintain a comfortable ambient light level, hovering around 50 foot candles, the team used a variety of sources throughout the store. Minimal linear fluorescent direct/indirect fixtures illuminate the aisles, while additional light is supplied by high-bay compact fluorescents, aluminum-reflector pendants, fiber optics, wall sconces, and MR16 and adjustable ceramic metal halide track lighting.
The fiber optic system in particular helped lower the watts per square foot, as well as provided a heat-free source to illuminate food cases. With adjustable accent lights and multi-beam fixtures installed in 11 departments, the system of 54 lamps lighting 408 individual fixtures (each source can light up to 8 endpoints), has the capability to replace 400 watts with 68 watts.
Enclosed cases, such as those used for desserts, gelato, and charcuterie, are illuminated from above with recessed fiber optic fixtures and frequently also include internal fluorescent case lights. Open cases of seafood on beds of ice also use the fiber optics above; however are also accented with metal halide and MR16 track lighting.
The designers addressed issues of discoloration and acceleration of bacterial growth and decomposition in the aged beef department (a result of ultraviolet and infrared wavelengths) with ultraviolet-free 'natural color' 3800K fluorescent lamps lining the inside perimeter of the cooler window. With traditional lamps, yellow and green portions of the visible light spectrum dulled the shades of red in the meat, but with the specialty lamps, meat is stored safely and remains visually appealing.
While metal halides and MR16s will be phased out in the future to make way for more efficient light sources, CTA's O'Leary 'would still like a warmer color rendition in some areas.' With every store, the lighting method continues to evolve. sallie moffat