Architectural Lighting Design PDF

Module 2: Artificial Illumination and Daylighting Topic 3: Architectural Lighting Design Standard Lighting Design vs Architectural Lighting Design Standard Lighting Design is to allow us to see clearly and without discomfort while Architectural Lighting Design goes above and beyond standard lighti...

Module 2: Artificial Illumination and Daylighting Topic 3: Architectural Lighting Design Standard Lighting Design vs Architectural Lighting Design Standard Lighting Design is to allow us to see clearly and without discomfort while Architectural Lighting Design goes above and beyond standard lighting design that focuses on enhancing the design of buildings and other physical structures using light. This can be done with natural light, electric light or the combination of both. Architectural lighting design relies on three fields in order to produce superior lighting solutions, and all three are equally as important. Architecture, interior design, and electrical engineering. What is architectural lighting design? Architectural lighting design is a field of work or study that is concerned with the design of lighting systems within the built environment, both interior and exterior. It can include manipulation and design of both daylight and electric light or both, to serve human needs. Why is architectural lighting design important? Lighting can bring an emotional value to architecture and plays a vital role in the way people experience buildings and structures. Whether it’s natural or artificial lighting, light draws attention to features, textures, colors and shapes to help architecture reach its true purpose. The Concept of Architectural Lighting Design In order to create a successful balance between lighting and architecture, there are three main aspects involved. The aesthetics, function, and efficiency. Aesthetics The aesthetics of architectural lighting design is where designers and architects focus on the visual impact the balance of lighting and architecture will have on people. They determine how they want individuals to feel when they enter and move around a given space. The aesthetics are extremely important when it comes to hospitality lighting, such as restaurants, bars and leisure complexes. Function The function of lighting cannot be ignored. Of course, we want architectural light ing to look fantastic, but we need to ensure it serves its main purpose – to help us see. The floors and walls should be illuminated properly to allow safe navigation through a room or when entering a building. This creates the feeling of reassurance. Efficiency With the ever-growing concern for the health of our environment, sustainability must be considered when designing architectural lighting. This can be achieved using energy-efficient LEDs, making sure light is reaching its target for minimum wasted light, and remembering that the quality of light is more important than quantity. Color Rendition of Light Sources Introduction The color quality of a light source relates to its ability to faithfully reproduce the colors of objects, effectively render colors that humans prefer, and efficiently aid in color discrimination. White light produced by an artificial light source is a mixture of various or several monochromatic colors from the visible portion of the electromagnetic spectrum from approximately 400 nm (nanometer) to 700 nm. The relative amount of radiation at each wavelength of the visible radiation spectrum is known as spectral power distribution (SPD). The SPD of a light source determines its color characteristics: the color appearance of a light source itself and its color reproduction performance. Importance of Color in Lighting Artificial lighting is a versatile tool that can be utilized to transform a space. It can be used in public areas to enhance performance and worship productions or within private establishments as functional or decorative lighting solutions. A survey of lighting professionals concluded that color is a critical consideration in all lighting applications and that it is typically more important than light efficacy. Why is this? Similar to the way physical color influences psychology, the color of lighting also has a physiological effect on humans. DEFINING COLOR REGARDING LIGHTING APPLICATION Those who plan on installing a new lighting design-build should make themselves familiar with the relevant color terminology:  Lumens, Watts & Kelvins: Lumens are measurements of light brightness while watts are measurements of energy consumption. Efficacy is  the measurement of lumens per watt. A Kelvin is a unit of thermodynamic temperature used in depicting correlated color temperature.  Color Mixing: Color mixing in light can be additive or subtractive. Individual light wavelengths are processed through cones within the eye. As several wavelengths enter the eye, they are processed via additive mixing. The cones then combine, for instance, the primary colors of blue and yellow to form green. In subtractive color mixing, colored filters only allow less intense wavelengths of their own primary colors to pass through, reducing the output of the source.  Chromatic & Achromatic Colors: White, grey and black possess no saturation or hue and are considered achromatic colors. The three attributes of color — hue, saturation and lightness — are found in colors characterized as chromatic.  Primary, Secondary & Complementary Colors: Primary colors are those that cannot be derived from another color and secondary colors are mixtures of two primary colors. Complementary colors are two colors that, when combined, either produce black or white light.  Color Modification: Color modification occurs when a colored surface is struck by a different colored light. Depending on the color of the surface, it will selectively filter wavelengths of light and reflect the others.  Color Interaction: Color wavelengths interact with surrounding colors by either acceding or receding. Depending on the contrast or complimentary colors present, our eyes will perceive these colors differently.  Color Rendering Index: The CRI measures the color characteristics of a light source, describing the source’s ability to display object colors realistically compared to a natural light source’s ability to do the same.  Correlated Color Temperature: The CCT describes the color output of the light source, measured in Kelvin. In regards to LED bulbs, though a bulb may glow with the same color as a black body heated to 5000K, the bulb itself will produce the same color without reaching that temperature. In the consumer world, two metrics are used to describe the color characteristics of a light source: correlated color temperature (CCT) and color rendering index (CRI). These metrics allow lighting designers and end-users to control and predict the color impact of different light sources. Color Rendering Index (CRI) Correlated Color Temperature Importance of Good Color Rendition The importance of a light source's color rendition is manifested in every aspect of life and work. Before the emergence of fluorescent lamps, the color reproduction performance of a light source had never been a concern. Halogen bulbs, incandescent bulbs and candle light all have a spectral power distribution that exhibits qualities considerably close to natural daylight, which has a perfect color rendition. This means the human visual system had been comfortable with perfectly rendered environments in both indoors and outdoors ever since our apelike ancestors began to evolve. Visually demanding tasks or color-critical applications at home, offices or studios, be it reading, writing, drawing, painting, photographing or makeup, require accurate color rendering in order to improve task performance, ensure color matching, and/or prevent eye fatigue. In industrial facilities such as textile factories, food processing plants, printing facilities, car painting workshops and microelectronics assembly lines, high color fidelity lighting allows workers to see colors accurately for performing precision tasks and quality checks while contributing to a safe, productive work environment. Color rendering is a critical factor to take into account in museum, gallery and exhibition hall lighting. The quality of light has a significant impact on visitor engagement. Accent light with a superior color rendition helps bring out the best in displayed artworks. White light abundant in long wavelengths in the spectrum of visible light can be used to boost the color saturation of the artwork or exhibits. The Color Science of LED Lighting The advent of LED technology renders the old color science of artificial light sources obsolete. Despite having a narrow spectral line width and producing monochromatic light such as red, blue or green, LEDs can be packaged to produce white light in any spectral power distribution and thus yield the desired chromaticity and color rendition. There are essentially two ways to produce white light with LEDs. White light can be created through additive color mixing by combining the three primary color diodes of red (R), green (G) and blue (B). However, this method is impracticable because 1) the spiked spectrum lacks spectral content in cyan, yellow and orange, which leads to an inadequate color rendition; 2) poor luminous efficacy due to the inefficiencies of green and red direct emission; and 3) high cost from both the use of multiple-colored diodes and the need for adequate control of these diodes. LEDs produced using wavelength conversion is called phosphor-converted LEDs (PC- LEDs) and are broken into two categories: blue-pump LEDs and violet-pump LEDs. Blue-pump LEDs consist of a blue LED chip which is coated with an organic polymer containing a yellow phosphor. The phosphor down-converts part of the higher energy, short wavelength blue light into lower energy, longer wavelength light which mixes with the remaining blue light to produce the desired white light. Violet-pump LEDs combine a violet LED and three phosphors (blue, green and red). The blue, green, and red phosphor emissions allow the LED package to distribute spectral energy across the entire visible spectrum, which results in an excellent color rendition. The color rendition features of LED lights have been divided into color fidelity and color quality. The color fidelity of LED lights quantifies the accuracy with which the color of illuminated objects appears. Color quality quantifies the appearance of different psychological weights according to the differences in color or brightness. Examples of Good Architectural Lighting Design