by Norman Russell LC, Principal Consultant, The Sextant Group
If you know that pedagogies and learning environments have significantly changed in the last ten years, go to the head of the class.
That is, if in fact there is a head of the class.
Yes, we all know that learning environments are changing. Rapidly replacing traditional classrooms with fixed instructor-oriented configurations, active learning spaces now include multi-form rooms that are flexible, small-group oriented configurations. The education process itself is not limited to the traditional classroom, but now includes informal learning locations anywhere on campus, both private and social, at virtually any time of the day or night.
In response to these trends (and in some cases, actually leading them), audiovisual and information technology systems have become mission-critical elements. Similarly, the planning and implementation of lighting systems for these spaces have become equally sophisticated and essential.
Within the last decade, the art and science of lighting design have progressed far beyond simple illumination. The science of visual processes has given us a new understanding of how light affects our ability to perform tasks, our comfort and sense of wellbeing, and the part that light plays in biological rhythms directly affecting our health.
Numerous studies have indicated a direct connection between lighting and our ability to learn. As a result of this new understanding there has been development of new lighting technologies. These advances offer vastly improved dimming capabilities, more precise metrics for the measurement of color production and color rendering, and the ability to design sophisticated lighting control systems. Of equal importance is the essential contribution made by the inclusion of daylight.
More Productive, Feel Better
The typical educational facility encompasses a wide variety of spaces representing specific application types: lecture hall, science lab, collaborative space, study hall, library, traditional classroom, computer lab, video teleconference and distance learning rooms, food service and recreational areas, etc. Learning occurs in varying ways in all of these spaces. Each space requires specific learning-related tasks. In some spaces, several tasks are present.
A primary function of lighting design is to plan for the most effective lighting in relation to each task. It is essential for the lighting designer to understand all tasks to be supported and the illuminance requirements for each.
For example, reading and writing on paper may require a high level of lighting intensity, but for tasks that require working at a computer, lower illuminance levels will make it easier to view a video display. Accurate rendering of color values is critical for some medical tasks and for artwork, but is not so important for a discussion of classical literature. A high level of contrast ratio between the brightest and the darkest areas in a space is important if accurate perception of large projected images is the task. A high contrast ratio may be inappropriate and even fatiguing in a collaborative classroom with smaller emissive video displays.
Some tasks involving manipulation of small intricate parts or very detailed work may require very high levels of illuminance, but glare and reflections may reduce productivity if incident angles and work surfaces are not carefully coordinated. Where the task is observing a presentation and taking notes, the lighting design must balance the task of reading and writing that require horizontal illuminance for the audience, in conjunction with vertical illuminance on the presenter/presentation, and little or no illumination on the projection surface.
By completing a thorough analysis of all space types and tasks requirements in a project, the lighting designer develops illuminance criteria for each, balancing required illuminance levels, color rendering, contrast ratios, glare control, veiling reflections, and balancing horizontal and vertical illuminance values. Supporting each task exactly, lighting promotes productivity while maintaining visual comfort.**
Lightening the Energy Bill
Lighting has a profound relationship with energy use and sustainability goals. In the typical educational facility, lighting accounts for approximately 30% of the total building energy use. Reduced energy demand and sustainability have become our reality and are a necessary component of any rational approach. Moreover, LEED® certification requirements, ASHRAE-IES building energy targets, and stringent building codes exert pressure on lighting design to reduce total lighting loads while planning lighting systems that provide productive, pleasing, and safe lighting. Currently, there is a vast range of highly efficient light sources, luminaires, and control systems. The key to selection of the right equipment for each application within the project budget, is precise design. Modern light sources such as LED, fluorescent, induction, and HID offer far superior efficacy in their ability to transform electrical energy into visible light. The use of these light sources is becoming more prevalent as the costs of initial research and development are amortized and the scale of production reduces unit costs.
The Ideal Light Source
Illuminance from daylight, even on cloudy or overcast days, has become an important part of lighting the learning environment. We know that exposure to daylight during our waking hours helps our bodies maintain the circadian rhythm alternating between darkness and light over a 24-hour period. Our coordination with this rhythm has a direct effect on our health and psychological sense of wellbeing.
Daylight includes all visible light wavelengths and reveals the full spectrum of color: it is our model for a perfect Color Rendering Index (CRI) of 100. This is especially important in laboratory classrooms where color identification is essential.
Moreover, daylight is free. At some level it is present all day, every day, around the globe. So, apart from its other advantages, planning for daylight in the learning environment can greatly reduce dependence on electric light. In fact, by employing a daylight harvesting strategy within the building design, a significant reduction in energy use can be achieved with no sacrifice in task illuminance.
It is a basic truth that the most efficient light is the one that is turned off. The lighting equipment industry has developed many means of controlling light: photo sensors to modulate luminaires in relation to available daylight, reliable occupancy sensors , and multi-scene programmable controls that make changes in the lighting a simple, easy task. There are several systems available specifically designed for the learning environment that allow the presenter’s attention to be focused on the presentation rather than trying to get the lighting right.
The Bottom Line
Effective lighting design for educational environment is more than just foot-candles and energy costs. It is also about providing an ideal space for human interaction, revealing architecture in a rich and pleasing way, and aiding in the search for meaning and understanding. This is lighting that reveals, that allows analysis and consideration of task, and that heightens awareness. This is lighting for learning.
The IES says…
To plan and design lighting systems effectively, good lighting designers consider the qualitative and the quantitative aspects of lighting for the educational environment by properly
- Defining project type and status
- Identifying application types
- Developing illuminance criteria
The formal process establishes a shared understanding of the project scope – new construction, adaptive reuse, addition – and an awareness of the client’s expectations. Once the varieties of learning environments are adequately examined, illuminance criteria for each type of space can be developed. The foundation of effective and efficient designs comes through informed choices.
The Illuminating Engineering Society’s IES Lighting Handbook, 10th Edition
About the Author
Principal Norman Russell is accredited as Lighting Certified (LC) by the NCQLP, the National Council on Qualifications for the Lighting Professions. The founder of Norman Russell Design in 1980 (now of one of The Sextant Group of companies), he is an industry leader in lighting for theatre, television, and architectural lighting.
Brain Bulb photo courtesy Solovyov Design. For more information, visit http://www.solovyovdesign.by