By Caryn Turrel, NEED Staff and Mother of a Future Architect
If you’ve ever had the opportunity to build a new home, whether a custom home or with a builder in a planned development, there are many things to think about. How large will the home be? Will it be two stories or one? What kind of foundation will support the house? There are choices to make at every turn, and a lot of thought goes into each one. Granite counter tops? Painted or stained cabinets? Wall colors? Brick, stone, siding, or stucco exterior? Fireplace? To wallpaper or not to wallpaper? (My suggestion is don’t do it. In a few years you’ll regret it. TRUST me.)
How much thought should we give to lighting? We shop for light fixtures, but do we think much about the placement of those fixtures, or the types of bulbs they will need? NEED’s materials talk a lot about the kind of lighting that is in our schools and homes, and how changing the light bulbs we use can save energy. But rarely do we discuss retrofitting these spaces with new fixtures. Energy use should be a major factor in choosing the fixtures we install.
When it comes to commercial buildings, however, it’s not as easy as just going to the lighting store and choosing our fixtures, or reaching for a particular light bulb on the shelf at our home improvement warehouse. Architects designing commercial buildings have to take into account a number of factors, such as the size of the space, the reflectivity of the surfaces within that space, how the spaces inside will be used, and how the use of the building might change in the future. Students at Ball State University’s College of Architecture and Planning (CAP) are taught to consider all of these factors when deciding the number, type, and placement of light fixtures in a commercial space.
However, Ball State CAP students are taught more than that. Sustainability is becoming an important component of architecture programs across the country, and is a major component of the BSU CAP program. Several courses focus on sustainability and energy use and a student organization, Ball State Energy Action Team (BEAT), is tasked with promoting energy awareness and showcasing opportunities for reducing energy use on campus. Third-year students in a course entitled Environmental Systems 2 were assigned to develop a plan for upgrading the lights in the CAP building studio spaces as part of BSU’s overall plan to remodel the current Architecture Building to be more sustainable and reduce its carbon footprint.
To successfully complete the assignment, the students needed to make a number of calculations. One was the proportion of the room above the light fixture, below the work surfaces, and between the work surface and light fixture. This assists in choosing an appropriately bright light that will illuminate the workspace adequately. Another was a calculation of the number of lumens per Watt the existing lights were producing, with the intent of increasing this ratio with the new light system. Knowing the lumens per Watt provides the lighting density in lumens per square foot, which determines whether the brightness of the light source is sufficient for the tasks being performed in the space.
Light “temperature” was an important factor as well. The temperature of light is a reference to the colors, or wavelengths, of light being produced, and is expressed in Kelvins. Warm white light is the lowest temperature, rated below 3000K. Cool white is between 3100 and 4500K, and daylight is 4600 to 6500K. Having the right temperature of light is important; while we don’t consciously react one way or another to a particular color of light, it has great influence on our mood and productivity. The warmer the light (lower Kelvin rating), the more calm and soothing the light is. The higher the color temperature, the more energized and alert we feel. Consider the bright lights of an airport vs. the warmer lights in a hotel room. Airports are bright, lively, alert spaces, while hotel rooms are usually calm, soothing, relaxing environments. Bathroom lighting is cooler while bedroom lighting is warmer. Thus, the students needed to choose lighting in a temperature range that would encourage productivity for their work space.
In developing a plan for the studio lighting, students needed to also consider aesthetics and feasibility. If a calculation determined 14.5 fixtures met the requirements, at least 15 fixtures would need to be installed. However, 15 might not work well in terms of wiring and the overall look of the space. Further considerations included justification as to how the fixtures selected and the number needed, would make for a truly green retrofit and meet the overall requirements for decreasing the building’s environmental impact. Fortunately for the students, there are now many commercially available light fixtures that use significantly less energy than fluorescent tube lights, produce an appropriate light temperature, and are aesthetically pleasing as well. Most of these are light-emitting diode, or LED, lights, and as LED technology continues to improve, they will continue to be installed in more commercial applications.
Turning on the lights in a classroom is something we don’t think much about; it’s a good thing someone else has thought about it. The architects of today and tomorrow are planning to make existing and future buildings much more energy efficient while keeping the lights on.