Hearst Tower
Parking Garage

214 North Tryon Street
Charlotte, NC 28202

The 46-story Hearst Tower is currently Charlotte’s second tallest building.  The building includes a 1400-space parking garage which needed to be more efficiently lit. Facilities managers of the garage were having to replace the lamps in the old 175W metal halide system every 6 months to provide the bright and safe environment needed for users.

Wide-body Zumtobel Chiaro luminaires were used to provide high vertical illuminance with excellent uniformity.  Each luminaire has two 54W high-output T5 lamps.  The Chiaro has a transparent high-impact resistant polycarbonate housing and a perforated reflector that allows for 20% uplight for a soft glow on the ceiling.  The prismatic lens offers excellent glare control and high efficiency.  The product is IP65 rated to protect against ingress of particulates and moisture.

The 2-per-bay installation provides a 2fc minimum illuminance with less than a 4:1 average-to-minimum ratio, thus exceeding recommendations from the IESNA.  While providing more light, the design falls well below power density requirements in that it requires only 0.19 Watts per square foot, 37% less than the limit dictated by ASHRAE 90.1, and half of the power used with the old system.  All this, and the lamps now only need to be replaced every 3 years.

www.hearsttower.info