AREN 4813 Building Illumination PDF

AREN 4813 Building Illumination Topic-2 Electric Lights Dr. Saleh Al-Saadi, [email protected] Civil & Architectural Engineering Department Sultan Qaboos University AREN 4813 Building Illumination 2 AREN 4813 Building Illumination 3 AREN 4813 Building Illumination 4 AREN 4813 Building...

AREN 4813 Building Illumination Topic-2 Electric Lights Dr. Saleh Al-Saadi, [email protected] Civil & Architectural Engineering Department Sultan Qaboos University AREN 4813 Building Illumination 2 AREN 4813 Building Illumination 3 AREN 4813 Building Illumination 4 AREN 4813 Building Illumination Incandescent lamps 5 AREN 4813 Building Illumination 6 AREN 4813 Building Illumination • Incandescent: In an incandescent lamp, light is emitted by electrically heating a tungsten filament until it is reddish-white hot. By increasing the current, the filament gets hotter and the light gets whiter (higher color temperature) Tungsten has a melting point of 3422 C. For a typical incandescent light bulb, the Tungsten filament operates at approximately 2500 C. Incandescent lamps wear out as the tungsten filament evaporates and condenses on the inside of the bulb, which causes the darkening of the glass. Eventually, as the filament gets thinner, it breaks. 7 AREN 4813 Building Illumination Electric Lights: Incandescent • Forms of Incandescent lamps: General Lighting Service (GLS) lamp 8 AREN 4813 Building Illumination • Incandescent: 9 AREN 4813 Building Illumination • Incandescent: 10 AREN 4813 Building Illumination Electric Lights • Incandescent: Example: 60A19 60: Wattage (60 W) A: Bulb shape 19: Maximum bulb diameter, in eighths of an inch. (19 ÷ 8 = 2.38 in) 11 AREN 4813 Building Illumination Electric Lights: Halogen Incandescent, Halogen: The evaporation of the filament can be reduced by adding halogen elements to the inert gases inside the lamp. These types of incandescent lamps can, therefore, be operated at higher temperatures without shortening lamp life excessively. This variation of the incandescent lamp is known as the tungsten halogen. Because of their intense light and small size, they are very popular as automobile headlights, projector lamps, and spotlights for accent lighting. 12 AREN 4813 Building Illumination Electric Lights Forms of Halogen lamps 13 AREN 4813 Building Illumination Discharge lamps 14 AREN 4813 Building Illumination • A major improvement in electric lighting came first with the development of the fluorescent lamp and then again with the development of high-intensity discharge lamps (mercury, metal halide, high pressure sodium). • All of these lamps are based on a phenomenon known as discharge, in which an ionized gas rather than a glowing hot solid tungsten filament emits the light. 15 AREN 4813 Building Illumination Electric Lights • Discharge lamps: All discharge lamps require an extra device known as a ballast, which first ignites the lamp with a high voltage and then limits the electric current to the proper operating level. Traditional ballasts that were made of copper coils are being replaced by electronic ballasts, which are more efficient and less noisy. 16 AREN 4813 Building Illumination Discharge lamps: Fluorescent 17 AREN 4813 Building Illumination • Discharge lamps: Fluorescent lamp Fluorescent lamps work by generating ultraviolet radiation in a discharge in low pressure mercury vapor. This is then converted into visible light by a phosphor coating on the inside of the tube. By using different kinds of phosphors, fluorescent lamps can be designed to emit various types of white light. The phosphor coating: there are a wide variety of phosphors available. The electrodes: generally coils of tungsten wire that are coated in a material that when heated will give off electrons readily. The gas fill: the lamp fill is made up of two components; a noble gas mixture and the mercury vapor. 18 AREN 4813 Building Illumination • Discharge lamps: Fluorescent lamp Fluorescent lamp was first introduced in the 1930s, it is still one of the best light sources. It is available in a wide variety of sizes, colors, wattages, and shapes The main diameters of lamp are the T12 lamps which are 38 mm in diameter, T8 lamps which are 25 mm and the T5 types which are 16 mm. T12= 12/8 inch= 12/8 inch*25.4 mm/inch= 38 mm Compact Fluorescent Lamps (CFL) 19 AREN 4813 Building Illumination • Fluorescent lamp designation : 20 AREN 4813 Building Illumination Discharge lamps: High Intensity Discharge (HID) 21 AREN 4813 Building Illumination • Discharge lamps: high intensity discharge (HID) In all of the high intensity discharge (HID) lamps, the light is emitted from a small arc tube located inside a protective outer bulb. 22 AREN 4813 Building Illumination High Intensity Discharge (HID): Metal Halide Lamps 23 AREN 4813 Building Illumination • Discharge lamps: high intensity discharge (HID) Metal Halide Lamps: can be quartz or ceramic Metal halide lamps were developed as a way of improving the performance of high pressure mercury lamps in terms of their color appearance and light output. They work by introducing the salts of other metals into the arc tube. 24 AREN 4813 Building Illumination • High Intensity Discharge designation : 25 AREN 4813 Building Illumination 26 AREN 4813 Building Illumination Solid State: Light Emitting Diode (LED) AREN 4813 Building Illumination • Solid State Light: Light Emitting Diode (LED) An LED is like a PV (solar) cell operating backward. Instead of light generating electricity, electricity generates light. It is a basic pn-junction diode, which emits light when activated. current flows easily from the p-side, or anode, to the n-side, or cathode Because the light is generated at a specific wavelength (color), LEDs are great for producing pure colored light that is appropriate for decorative or communication purposes such as traffic lights and building decoration. 28 AREN 4813 Building Illumination Comparison of lamp groups AREN 4813 Building Illumination Comparison of lamp groups AREN 4813 Building Illumination Comparison of lamp groups 31 AREN 4813 Building Illumination Luminaire: Lighting fixtures AREN 4813 Building Illumination Luminaires have three major functions: • supporting the lamp with some kind of socket, • Supplying power to the lamp, and • Modifying the light from the lamp to achieve a desired light pattern and to reduce glare. 33 AREN 4813 Building Illumination Luminaire 34 AREN 4813 Building Illumination Luminaire • Typical luminaires are divided into the following categories by the way they distribute light up or down: 35 AREN 4813 Building Illumination Luminaire • Typical luminaires are divided into the following categories by the way they distribute light up or down: 36 36 AREN 4813 Building Illumination Luminaire • Typical luminaires are divided into the following categories by the way they distribute light up or down: 37 AREN 4813 Building Illumination Mounting 38 AREN 4813 Building Illumination Mounting 39 AREN 4813 Building Illumination Mounting 40 AREN 4813 Building Illumination Mounting 41 AREN 4813 Building Illumination Mounting 42 AREN 4813 Building Illumination Mounting 43 AREN 4813 Building Illumination Mounting 44 AREN 4813 Building Illumination Control of Light distribution • Luminaires with a sizable direct component are most appropriate when high illumination levels are required over a large area or when the ceiling and walls have a low reflectance factor. • However, the quality of light might be poor (i.e., glare). For a better lighting quality, the light should be shielded from the human vision. For a standing man, the cut-off angle should not be less than 45° and for a setting man, the cut-off angle should not be less than 30°. 45 AREN 4813 Building Illumination Control of Light distribution • The quality of the lighting from direct fixtures can be significantly improved by the design of the fixtures. • There are several techniques used to improve these types of luminaires. 46 AREN 4813 Building Illumination Control of Light distribution • Baffles, Louvers, and Eggcrate Devices: louvers 47 AREN 4813 Building Illumination Control of Light distribution • Baffles, Louvers, and Eggcrate Devices: 48 AREN 4813 Building Illumination Control of Light distribution Parabolic Louvers • This type of louver is made of parabolic wedges with a specular finish. • These devices are extremely effective in preventing direct glare because the light distribution is almost straight down • However, they do not solve the problem of veiling reflections on horizontal surfaces. 49 AREN 4813 Building Illumination Control of Light distribution Lenses and Prisms on Clear Sheets • When the surface of clear sheets of glass or plastic is formed into small lenses or prisms, good optical control is possible. • The light is refracted so that more of the distribution is down and direct glare is reduced. • Round fixtures can use Fresnel lenses that can either concentrate the light like a convex lens or disperse the light like a concave lens. • Fresnel lenses are much less expensive than regular lenses because they consist of flat sheets with beveled grooves 50 AREN 4813 Building Illumination Control of Light distribution Reflectors No reflectors 51 AREN 4813 Building Illumination Lighting Systems Lighting systems can be divided into six generic types. In many applications, a combination of these basic systems is used: 1. 2. 3. 4. 5. 6. General Lighting Localized Lighting Ambient Lighting Task Lighting Highlighting (Accent) Lighting Decorative Lighting 52 AREN 4813 Building Illumination Lighting System General Lighting: this usually consists of more or less uniformly spaced, ceiling-mounted direct lighting fixtures. • • • It is a very popular system because of the flexibility in arranging and rearranging work areas. Since the illumination is roughly equal everywhere, furniture placement is relatively easy. The energy efficiency is usually low because noncritical work areas receive as much light as task areas. 53 AREN 4813 Building Illumination Lighting System General Lighting: Light quality, especially veiling reflections, is also a problem, since it is hard to find a work area that does not have a lighting fixture in the offending zone 54 AREN 4813 Building Illumination Lighting System • • • • Localized Lighting: is a non-uniform arrangement in which the lighting fixtures are concentrated over the work areas. Fairly high energy efficiency is possible since non-work areas are not illuminated to the same degree as work areas. Veiling reflections and direct glare can be reduced because this system affords some freedom in fixture placement. Flexibility in rearranging the furniture, however, is reduced. 55 55 AREN 4813 Building Illumination Lighting System Ambient Lighting: is indirect lighting reflected off the ceiling and walls. • It is a diffused, low-illumination, level lighting that is sufficient for easy visual tasks and circulation. • It is usually used in conjunction with task lighting and is then known as task/ambient lighting. • Direct glare and veiling reflections can be almost completely avoided with this approach. • The luminaires creating the ambient lighting can be suspended from the ceiling, mounted on walls, supported by pedestals, or integrated into the furniture. • If used with task/ambient lighting strategy, the ambient illumination level should be about one-third of the task. 56 AREN 4813 Building Illumination Lighting System Examples of Ambient Lighting: 57 AREN 4813 Building Illumination Lighting System Task Lighting: usually attached to or resting on the furniture • It has the greatest flexibility, better light quality, and high energy efficiency. • Direct glare and veiling reflections can be completely prevented when the fixtures are placed properly. • The individual control is possible with this personal lighting system. • Task lighting is complemented with ambient lighting. This is called task/ambient lighting. • Not only is task/ambient lighting the most sustainable by using less energy than standard lighting, it is also the highest- quality lighting. 58 AREN 4813 Building Illumination Lighting System Highlighting (Accent) Lighting: is used whenever an object or a part of the building is to be highlighted • Accent illumination should be about ten times higher than the surrounding light level. • Since this type of lighting is very variable and is a very powerful generator of the visual experience, designers should give it careful attention. 59 AREN 4813 Building Illumination Lighting System Examples of Highlighting (Accent) Lighting: spot lights 60 AREN 4813 Building Illumination Lighting System Examples of Highlighting (Accent) Lighting: wall-washers Wall-washer light 61 AREN 4813 Building Illumination Lighting System Decorative Lighting: the lamps and fixtures themselves are the object to be viewed (e.g., chandeliers) • In most cases, the decorative lighting also supplies some of the functional lighting. 62 AREN 4813 Building Illumination Lighting System Decorative Lighting: 63 AREN 4813 Building Illumination Lighting System Common Design misconceptions: 2-Narrow spot light create shadows and 1-Too many spot and ceiling lights hinder the details of human face AREN 4813 Building Illumination Lighting Design Applications Common Design misconceptions: 3- the use of the same lighting level regardless of the activity and function inside the space 4- not using enough accent lights on important objects No accent light to the paintings on top of the bed 65 AREN 4813 Building Illumination Lighting Design Applications Common Design misconceptions: 5- using lights that have high probability of creating glare 66 AREN 4813 Building Illumination Lighting Design Applications Common Design misconceptions: 6- overuse of decorative lights 67 AREN 4813 Building Illumination END