Pedestrian walkway gets lighting upgrade

A pedestrian area uses primarily LEDs to light the way between two Chicago buildings.

By Shanna Olson, LC, MIES, KJWW Engineering Consultants, Chicago July 15, 2014

This 22,000-sq-ft lobby renovation in the heart of Chicago connects two buildings and a hotel; about 60,000 pedestrians walk through its doors each day. Programmatic requirements included creating a clean, contemporary aesthetic that enhances pedestrians’ wayfinding. Energy and maintenance reduction as well as long-term flexibility were equally essential. Rich, mahogany-toned wood and live bamboo planters balance the broad spans of warm white stone. A wood screen wall provides a visual separation and subtle wayfinding between the hotel and office lobbies.

The lighting design uses only LED lamp sources, with the exception of linear high performance T8 (HPT8) fluorescent wall washers and ceramic metal halide (CMH) adjustable heads for plant lighting. Square LED downlights with varying lumen output provide cohesion and exemplify the clean aesthetic of the space. After a mockup, 3000 K color temperature was selected to amplify the perception of warmth and comfort. The bamboo, however, required 4000 K to maximize growth, and the design team chose to use both color temperatures. This differential also allows the planters to pop. LED multi-head luminaires demarcate seating areas, while LED linear grazing and cove luminaires enhance the wood screen wall and heighten columns.

At the coffee kiosk, lower-lumen square downlights and LED edge-lit signage create a composition of elements. Continuing this theme, LED decorative-lensed downlights and mini LED cove lights are used in conjunction with wood paneling to wrap the escalators.

The lighting power density is less than 0.75 W/sq ft and beats IECC 2012 by more than 30%.

This project used a DALI-based intelligent control system, which was augmented with daylight and occupancy sensors. By providing an advanced lighting system, the project will not only save significant energy, but will minimize maintenance and increase flexibility and long-term functionality. The addressable nature of the selected control system enables the creation of various lighting scenes, which allows this multifunctional space to be used in several ways and enables the building owner to reprogram as needs change. During commissioning, this flexibility was used at several stages, modifying scenes and adjusting the light levels. In the long run, this system will serve to reduce energy while adding wayfinding, flexibility, and functionality.  

Shanna Olson is Senior Lighting Designer for KJWW Engineering Consultants. She is NCQLP certified and experienced in creating lighting designs for municipal, health care, educational, commercial, and residential clients.