By: Galina Zbrizher
The newly built 16,000 square metre Campus Centre of the British Columbia Institute of Technology (architect: Architectura, Waisman, Dewar, Grout, Carter Inc.; electrical consultant: M.D. Stanley Engineering) is an eight-storey building that consists of street level retail, a conference/seminar centre, offices, and over 40 classrooms and teaching spaces, including state-of-the-art laboratory facilities.
The lighting system complements the modern glass and steel architectural elements (see photo) and provides the comfortable visual environment required for the educational facility.
One of the key components of the building’s lighting is daylight. The design team developed strategies for the daylighting/artificial lighting integrated systems to ensure balanced light distribution across the building.
The building envelope has shading devices to reduce solar gain and at the same time to allow desired visible light transmission and penetration. The project architect Reiner Fessler and project electrical engineers Harry Dowhan and Dean Kaardal collaborated in solving interaction of the electrical and the daylight.
To identify the best combination of the daylighting/electrical lighting package, a research study made possible by an Energy Efficiency Incentive Program offered by the Power Smart Division of BC Hydro was conducted at the Lighting Design Lab in Seattle, Washington. The study used computer modelling and simulated daylight testing on a reduced scale model of a typical classroom.
For classrooms facing southeast and southwest, side lighting is used. The study identified the benefits of using interior light shelves and suggested the best dimensions, position and orientation for these, thus increasing the quantity of usable daylight.
The simulation showed that, without the light shelves, the sunlight would penetrate directly into the classroom and light one-third of the room to an illuminance level of about 700 lux, while further into the room the illuminance levels would decrease dramatically. The interior light shelves were designed to redirect the sunlight on the ceiling and into the space so that luminance is better balanced and the illuminance is levelled to about 300 lux throughout the room.
The study concluded also that while sunlight glare exposure can be dramatically reduced by exterior architectural glass fins, direct sunlight entering the upper glazing and bypassing the light shelf can be controlled by vertical louvered blinds.
bc campus In the early stage of the electrical lighting design, it was predicted that three evenly spaced, continuous rows of indirect luminaires would be required to provide control flexibility and a maintained illuminance level of 600 lux in the classroom. The study suggested that the luminaires would perform better if placed parallel to the glazing and calculated the best mounting height and location considering the daylighting aspect. To provide task lighting, the closest segment in each indirect lighting row is controlled separately.
The study outlined that by using a combination of daylight photo sensors and occupancy sensors, increased flexibility and energy savings could be obtained by utilizing dimming control rather than controlling the lighting system with switches.
In addition, the study also showed that, due to the particular orientation of the building, it would be more effective to use one daylight photo sensor for the luminaire row adjacent to the window and another sensor for the remaining two luminaire rows, rather than using one sensor per row.
The installed indirect lighting system provides well balanced luminance and illuminance on the space and work surfaces. The system is both cost effective and flexible enough to accommodate every eventuality concerning the instructions that are presented either on task illuminated blackboards or by the overhead projector.
Use of the daylight control system, controls such as occupancy sensors, preset dimmers and use of energy efficient light sources dramatically reduced maintenance costs and exceeded requirements set by the IES/ASHRAE 90.1 standard.
The BCIT Downtown Campus Centre exemplifies human creativity sustained by the computer resources and modelling techniques, and is in perfect harmony with the character of the building.