Case Study: Banner MD Anderson Cancer Center, Gilbert, Ariz.
Challenge: Provide exceptional illumination within energy-consumption limits and dark-sky guidelines.
A glowing vertical prism more than 60 ft tall anchors a prominent corner of the 3-story MD Anderson Banner Cancer Center, projecting the outpatient center’s image as a beacon of hope in the fight against all forms of cancer. To make this iconic “lantern” a reality, a special lighting solution was required. Many factors guided the lighting and control system design of this feature: the color of the lantern’s light needed to change periodically to represent each of the different colors of cancer awareness, the illumination needed to be precisely and evenly controlled, the solution needed to be achievable within energy-consumption limits and Arizona dark-sky guidelines, and it had to have minimal maintenance requirements. A combination of RGB color-changing LEDs and Digital multiplexing (DMX) controllers coordinated to light the lantern structure proved to be the ideal strategy to achieve all these goals.
Lighting the interior of the cancer center posed challenges as well. For increased safety, requested levels of illuminance exceeded the Illumination Engineering Society’s recommendations in a number of areas including patient toilets and medication rooms. The client also prescribed high ceiling heights with fully recessed fixtures in these areas, making compliance with ASHRAE 90.1-2007 lighting-power density allowances complex. A highly efficient lighting strategy was needed to meet the code and client-driven criteria. Public circulation areas are predominately daylit, and lighting fixtures with integrated daylight sensors were specified to avoid the need to locate, install, and wire separate daylight-sensing elements.
The timing of this project put construction before the tipping point of the LED cost/benefit revolution, so T5HO (high-output T5 fluorescent) lighting—narrower in diameter than standard T8 fixtures but providing twice the light output and using 30% less electricity—enabled the desired luminance with smaller, slimmer luminaires leveraging fixture efficiency in many interior spaces. The result is a facility that went beyond code compliance to provide a lighting and control system design that is energy-efficient, easy to use, and straightforward to maintain.