Presentation on theme: "Group 7: Masaa Tom Ong’olo Martha Malack Sheila Ian Omondi Brian Mathews."— Presentation transcript:
Group 7: Masaa Tom Ong’olo Martha Malack Sheila Ian Omondi Brian Mathews
HISTORY OF LIGHTING
Daylight architecture Daylight architecture is adapting to the lighting requirements with natural light. The assize of rooms was also determined by the availability of natural lighting and ventilation. Different basic types of daylighting architecture developed in conjunction with lighting conditions in the various climatic zones of the globe.
Artificial lighting The flame which was the second light source was separated from fire, the source of warmth. Burning branches were removed from the fire and used for the specific purpose of lighting. All manner of chandeliers and scones were developed in a wide variety of styles. Light began to mark man’s night-time.
Science and lighting Francois Argand constructed a lamp that was named after him, the Argand lamp. Use of optical instruments was also evident at this time and basic theories about light originated. Development of photometrics by Boguer& Lambert at around the 18thC Street lighting and stage lighting developed in areas of signaling especially in light houses.
Gas lighting End of 18thC efficiency of gas lighting was demonstrated in a series of pilot projects. Thermo lamps were developed and with the coupling of coke recovery and gas production, gas lighting became an economic proposition as entire sections of towns could benefit from a central gas supply. Luminous efficacy and colour appearance in the process of thermo luminescence depended on the type of material.
Electrical light sources Beginning of the 19thC saw the development of arch lamps that were first operated on batteries. Mid-century self adjusting lamps were developed and later generators. Further developments: o Glass bulb o Moore lamp o Mercury vapor lamp
Quantitative light design 100 years later luminance levels similar to those of daylight could technically now be produced in interior living and working spaces or in exterior spaces. Glare problems and harsh shadows. Attempt and failure to provide comprehensive street lighting. Task lighting. Guidelines for lighting in general. Provision of uniform ambient lighting.
New kind of lighting design A new approach to designing with light related more intensely to architectural lighting and its inherent requirements was developed. It had significance for extensively glazed facades, which were not only openings to let in daylight but also to give architecture a new appearance at night through artificial lighting. Joachim Teichvnuller defined ‘lichtarchitektur’ as architecture that conceives light as a building material and incorporates it purposefully into the overall architectural design.
The influences of stage lighting Stage lighting strives to create illusions. Light alone can be applied on the same set to create the impression of different times of day, changes in weather…
Quantitative lighting design Richard Kelly broke away from the idea of uniform illuminance as the paramount criterion of lighting design. He substituted the issue of quantity with the issue of different qualities. He differentiated between three basic functions: o Ambient light o Focal glow o Play of brilliance
Lighting engineering and lighting design Differentiated lighting required specialized luminaires designed to cope with specific lighting tasks. Industry had to meet the designers’ demands for new luminaires, and further developments in the field of lamp technology and luminaire design were promoted to suit particular applications required by lighting designers. Compact light sources: o Halogen lamps o Metal halides o Fluorescent body
And its techniques
Introduction Since the beginning of habitable construction, daylighting has been a big factor in the designs of buildings. Daylighting is the practice of placing windows (and reflective surfaces) so that during the day natural light provides effective internal lighting.
Day Lighting reduces energy costs in the building while at the same time enhancing visual comfort. The presence of direct sunshine in the interior environment is also of great physiological benefit.
Techniques of daylighting Building Orientation and Geometry The orientation of the building plays a big role in the amount of daylight received in the building. A building oriented in the E-W axis will receive more daylight. The orientation of the building with regards to the site is also important. The fenestrations should be designed to face away from obstructions which will otherwise block daylight
The geometry of the buildings in terms of the walls, ceilings, floors and windows and how they relate with each other influences daylighting as well
Size and Location of Windows The larger the windows, the more daylight will be received in the illuminated room. Windows located on facades receiving more daylight will in turn have the rooms they are in with more light
Type of Window There are various types of windows that can be used on a building. Some of the most common are vertical windows, skylights and clerestories. All these types of windows bring in daylight, but of different quality in the spaces they illuminate.
Ground and wall treatment Smooth and light coloured walls will reflect daylight in the interior of the building, providing light of great quality. Up to 40% of daylight can also be reflected into the interior spaces through reflection from the ground, the percentage depending on the ground treatment.
Light shelves and light tubes Light shelves are horizontal devices on windows used to reflect daylight farther into a room. They can be completely outside or halfway in. Light tubes are tubes from the roof used to provide light to a focused area of the interior
What is artificial lighting? This is basically any lighting that is not from sunlight. It could also be referred to as light that is man made.
Light Sources Light sources are instruments of producing light. Light sources are technical devices which convert usually electric energy into radiation - partly to light. Based on the way they work, light sources are divided into two types of lamps: - 1.incandescent, and - luminescent.
Incandescent lamps In incandescent lamps, light is produced by the radiation of a filament at high temperature. The spectrum of the light generated in this way contains radiation at every wavelength and its spectrum is monotonous. A considerable amount of heat is generated at the same time as light. Incandescent lamps used in practice are - filament incandescent lamps, - tungsten halogen lamps for mains voltage, and - low voltage tungsten halogen reflector lamps.
filament incandescent Light in an incandescent lamp is produced by a tungsten filament heated by electric current. The red hot tungsten filament (about 2800 K) is in a bulb filled with a noble gas. The electric connection is made possible by a special base at one or both ends.
Types of incandescent bulbs
TUNGSTEN HALOGEN LAMPS FOR MAINS VOLTAGE Their design differs from that of standard incandescent lamps in the following ways. The light source is linear, the envelope is made from quartz glass, and the tube contains halogens - hence the name. Bases are situated at both ends of the tube. Their operation is the same as that of standard incandescent lamps
low voltage tungsten halogen reflector lamps. In these lamps, a small light source is built together with a mirror lamp, thus becoming a compact unit for further installation. They operate in essentially the same way as standard incandescent lamps.
Luminescent lamps In luminescent lamps light is generated by excited electrons. An electric arc excites light in a so- called arc tube or on the surface of the envelope, as the case may be. The spectrum of the light generated this way is not necessarily continuous, radiation is much larger in certain narrow bands than in others, and the spectrum is not monotonous. Luminescent lamp used in practice are - fluorescent lamps, - compact fluorescent lamps, - mercury lamps,
fluorescent lamps The light is produced predominantly by the fluorescent powder covering the inner wall of the tube. This powder transforms the UV radiation of the gas discharge into visible light.
COMPACT FLUORESCENT LAMPS Compact fluorescent lamps are usually relatively small fluorescent light sources that are or can be built together with the auxiliaries partly or completely. They operate the same way as standard fluorescent lamps
Mercury lamps Mercury lamps belong to the group of HID (high intensity discharge) lamps. These lamps have two envelopes. The inner quartz envelope is an arc tube. The gas discharge is started by a starting electrode. The radiation generated by the electric current through mercury vapour is only partly light, its invisible part is transformed into light by the fluorescent powder on the inside surface of the outer envelope. Mercury lamps need auxiliaries (ballast or starter-transformer) for their operation.
Gas Lighting. Gas lighting is production of artificial light from combustion of a gaseous fuel, such as hydrogen, methane, carbon monoxide, propane, butane, acetylene, ethylene, or natural gas. Before electricity became sufficiently widespread and economical to allow for general public use, gas was the most popular means of outdoor and indoor lighting in cities and suburbs. Early gas lights had to be lit manually, but many later designs are self-igniting. Gas lighting today is typically used for camping, where the high energy density of a hydrocarbon fuel, combined with the modular nature of canisters (a strong metal container) allows bright and long lasting light to be produced cheaply and without complex equipment. In addition, some urban historical districts retain gas street lighting, and gas lighting is used indoors or outdoors to create or preserve a nostalgic effect.
Light –quality and features Controlling light Light fixtures /light luminaires
Specific qualities of light create different perceptual conditions and thereby influence and control human perception. Quality is unfluenced by -Illuminance - Light distribution - beam direction - the colour of a light installation - glare limitation Quality and features
Quantity of light Much investigation has gone into lighting conditions in the working environment to establish illuminance levels for optimum visual performance. Def: Visual performance is the ability to perceive and identify objects or details, i.e. visual tasks with given contrast between the object viewed and the surrounding area Visual performance generally improves when the illuminance level is increased but decreases rapidly at extremely high illuminance levels due to glare effects
Illuminance levels recommended for various tasks Recognize facial features: 20 lux At the work place lux At the operating theater up to lux
Visual perception Visual perception is influenced by 3 factors - light -the object -the perceiving being The pattern of luminances projected to the retina forms a basis for a complex process at the end of which is the image we actually see. This involves some aspects such as -the laws of gestalt -constancy phenomena -the information content of the object that is being perceived. The image perceived is therefore not identical to the patters of luminances that fall on the retina but rather to the Eg. The formation of shadows on a spatial body. The luminance pattern is not interpreted as being unevenly lit but rather as the feature of a three dimensional form
Diffuse and directed light Diffuse light - produced by extensive areas that emit light such as luminous ceilings or reflected light from illuminated ceilings and walls. -illuminates the entire space but produces reduced shadows and reflections. Directed light- emitted from point sources ; compact light sources. - essential for production of shadows on objects and structured surfaces and reflection on specular surfaces.
Modelling The task of lighting design is therefore to create a suitabe ratio of diffuse light to directed light to meet the requirements of each individual situation Where the spatial quality or the surface structure is of prime importance, lighting that emphasises shapes and forms is required. Only in situations where spatial quality and surface structure are of no importance, or if they are disturbing factors, can completely diffuse lighting be used The shaping of our environment through light and shade is of prime importance for our perception of spatial forms and surface structures Modelling is primarily effected using directed light Too much shaping can conceal information if the shadows cast are so stark that parts of the object are concealed by the darkness
Brilliance Brilliance is produced by compact, point light sources and is most effective when applied with an extremely low proportion of diffuse light Eg. The effect of a candle light in evening light Objects that refract this light are perceived as specular, e.g. illuminated glass, polished gems or crystal chandeliers. Brilliance is also produced when light falls on highly glossy surfaces, such as porcelain, glass, paint or varnish, polished metal or wet materials Accentuates the spatial quality and surface structure because sparkling effects are mainly evident along edges and around the curves on shiny objects. Sparkling effects are generally used in practice to make objects or spaces more interesting and prestigious or precious. It is effective because it attracts our attention with the promise of Information content. If the brilliance is of no information value then it becomes disturbing glare also known as glare
Glare discomfort glare degree of which depends on the number, size, position, and luminance of the glare sources. Disability glare- visibility is reduced to zero eg. From a glossy magazine Veiling reflections- eg. Lighting fixture images on your computer screen
Luminous colour and colour rendering Def: Degree of change which occurs in the colour effects of objects through lighting with a specific light source in contrast to the lighting with a comparative reference light source eg. a thermal radiator or daylight. It is therefore a comparison of the similarity of colour effects under two types of lighting.. Different light sources have different Colour rendering indexes which is the measure of the ability of a light source to accurately render all frequencies of its color spectrum when compared to a perfect reference light of a similar type (color temperature). It is rated on a scale from The lower the CRI rating, the less accurately colors will be reproduced
CONTROLLING LIGHT Reflectors Reflectors are designed to redirect the light emitted from a lamp in order to achieve a desired distribution of light intensity outside of the luminaire. Glossy or mirrored reflectors produce direct light, while matte finish reflectors produce scattered, or diffuse light. Transmitters Transmitting materials in luminaires can be transparent. This applies to simple front glass panels, or filters that absorb certain spectral regions but transmit others, Absorbers Primarily used for shielding Light sources for visual comfort. Typical absorbing elements on a luminaire are black multigrooved baffles, anti-dazzle cylinders, barn doors or louvres in various shapes and sizes
Def: A complete lighting unit that produces and distributes light to fulfill the design goals for the lighted space.
Stationary luminaires Are an integral part of the architecture. Are mounted rigidly therefore direction of lighting is also fixed Occasionally it is possible to vary light direction Can be subdivided according to characteristic and design into
Downlights Direct light predominantly downwards Are usually mounted on the ceilings or walls ( especially in the hallways). They may be recessed, semi-recessed, surface, pendant and wall mounted. – the light patterns they produce have a typical hyperbolic shape (scallops). Downlights are available for a wide range of lamps, the most frequently used being Compact light sources such as incandescent lamps, halogen lamps, high-pressure discharge lamps and compact fluorescent lamps. recessed, semi-recessed, surface, pendant and wall mounting
Downlights used on an exterior garden
Double focus downlights Have similar properties to conventional downlights, But the special form of the reflector allows high luminous efficiency even though the ceiling aperture is small suitable for glare-free, horizontal ambient lighting in rooms with high ceilings in which the highest level of visual comfort is required. A downlight and a double focus downlight respectively
Washlights Have asymmetrical lighting distribution have asymmetrical lighting distribution, which not only directs the Light vertically downwards, but also directly onto vertical surfaces. They are used to achieve uniform illumination over wall surfaces as a complement to horizontal lighting. Depending on the type, they are used to illuminate a section of a wall, the corner of a space or two opposite sections of wall
Directional spotlights Light internal and external architectural features. provide accent lighting of specific areas or objects. They can be used for different lighting tasks. Their light distribution is narrow to medium.
Air handling downlights They represent a dual function solution comprising lighting and air-conditioning and make for harmonious ceiling design. Can be provided with connections for fresh air supply, for air return or for both air-supply and air return.
Uplights Emit light upwards Can be used for lighting up the ceiling, indirect lighting by reflected light from the ceiling or wall illumination through grazing lighting. Up-downlights combine a downlight and an uplight in one fixture. These are used for the simultaneous lighting of floor and ceiling or for grazing lighting over a wall surface. They are available in wall and pendant version An up-downlight
Louvered luminaires Are designed for linear light sources such as fluorescent lamps or compact fluorescent lamps. Their name derives from their anti- dazzle attachments that may b eanti-glare louvres, light controlling specular reflectors or prismatic diffusers. Have little or no modeling effects Are predominantly used for lighting wide areas Similar to downlights, they are available for recessed or surface mounting or as pendant fixtures. A louvered lamp designed by Stuart Fingerhut
Asymmetic louvered luminaies. Predominantly radiate light in one direction only. They can be used for the uniform lighting of walls or to avoid glare caused by light projected onto windows or doors.. VDT louvred luminaires Are designed for use in spaces with computer workstations.. Direct-indirect louvred luminaires. Are suspended from the ceiling or mounted on the wall. They produce a direct component on horizontal surfaces beneath the luminaire and at the same time light the ceiling and provide diffuse ambient lighting. Types of louvered luminaires Air-handing louvred luminaires Are designed to handle supply air and return air and provide a more harmonious ceiling layout
Washlights Washlights are designed to provide uniform lighting over extensive surfaces, mainly walls, ceilings and floors.. Wallwashers Ceiling washlights Floor washlights
Integral luminaires Some forms of lighting use the architectural elements as controlling components of the lighting. Typical examples are luminous ceilings, cove lighting or concealed cornice lighting. Standard luminaires, e.g. for fluorescent lamps or high-voltage tubular lamps can be used for such applications. Luminaires can be integrated into the architecture in order to accentuate architectural elements, e.g. to reveal contours Luminous ceilings Cove lighting Concealed cornice lighting
Movable luminaires Are not confined to a fixed position, but can be adjusted and repositioned as required. The most common types are: They illuminate a limited area, with the result that they are rarely used for ambient lighting but predominantly for accent lighting. Movable wallwashers can provide temporary or permanent lighting on vertical surfaces. Are generally equipped with halogen lamps for mains voltage,metal halide lamps or with fluorescent lamps (linear and compact types} SpotlightsWall washers
Light structures Light structures are systems comprising modular elements that take integrated luminaires. Movable luminaires, e.g. spotlights, can be mounted and operated on light structures.
Where can one get lighting fixtures? Vishelectric ltd. Kenya lampshades ltd Galaxy lighting ltd Noor lampshades ltd Powertechnics Tile & Carpet Centre Lighting Mania at Nakumatt supermarkets Babu Pindolia Suppliers
Lighting Basics General Lighting -provides an area with overall illumination. Also known as ambient lighting, general lighting radiates a comfortable level of brightness, enabling one to see and walk about safely. It can be accomplished with chandeliers, ceiling or wall-mounted fixtures, recessed or track lights, and with lanterns outside your home. A basic form of lighting that replaces sunlight, general lighting is fundamental to a lighting plan. Task lighting -helps you perform specific tasks such as reading, sewing, cooking, homework, hobbies, games, or balancing your checkbook. It can be provided by recessed and track lighting, pendant lighting, and portable lamps. Task lighting should be free of distracting glare and shadows and should be bright enough to prevent eyestrain. Accent Lighting- adds drama to a room by creating visual interest. As part of a decorating scheme, it is used to spotlight paintings, houseplants, sculpture, and other prized possessions, or to highlight the texture of a wall, drapery or outdoor landscaping. Accent lighting requires at least three times as much light on the focal point as the general lighting around it. This usually is provided by track, recessed, or wall-mounted fixtures.
Lighting in Whole Building Design ArchitectureArchitecture: Probably the largest impacts on electric lighting requirements and design come from the architectural orientation, massing, ceiling height, and section profiles that determine daylight availability in the building. Typically, south facing orientations, narrow floor plates, high ceilings, and open sections tend to bring more usable daylight into the building and correspondingly reduce the electric lighting use. Lighting designers should be brought onto the project team early in the design process so that they might have an impact on these early siting and massing decisions.
Interior Design: Interior design choices, such as surface finishes, can have a dramatic impact on the lighting system and how much light is required to make a space feel bright. Dark wood finishes require more light (and electricity) to brighten a space than light colored surfaces. The visual elements of lighting equipment must also coordinate with the interior design. Interior Design
Structural Coordination: Lighting designers must understand how a lighting system might be incorporated into structural elements: coves, beams, and columns; as well as what structural components may become lighted surfaces. Structural Coordination
Effective Design (Sustainability)Sustainability As part of a whole building design process, lighting designers develop an electric lighting solution that addresses: Daylighting—the design should supplement the available daylight Daylighting Task / Ambient / Accent systems—a lighting system that layers these components provides flexibility in its use and comfort. Control of systems—with daylight, occupancy, vacancy, schedule, time, and user preference.systems Efficient and effective luminaires—making the best use and distribution of the light source.luminaires Efficacious light sources—designer should choose the most efficacious (lumens of light per watt of power) that still accomplishes the design goal for that source and luminaire. Exterior Lighting—while enough light needs to be provided for nighttime visibility, too much can cause glare, adaptation problems, and light trespass.
Sources of Affordable Lighting Fluorescent Lighting Though commonly found in commercial lighting systems, fluorescent (or "gas discharge") lighting has come a long way. Always known for their efficiency and low cost, modern fluorescent lighting is available in warmer colors similar to traditional incandescent lighting. In addition, fluorescents run cooler than incandescent bulbs, making them a safe, affordable and ecologically friendly lighting source.
Dimmer Controlled Controlling lighting through a dimmer is a great way to save money on your electric bill, and increase the life of most bulbs. Typically solid-state devices, dimmers switch lights off and on approximately 120 times per second, creating the perception of relative brightness. By being "on" less often than non- dimmed lighting, dimmer-controlled lights use less electricity. And dimming lights by 25%, for example, will extend the life of the typical bulb by four times.
Dimmered controlled lighting
Compact Fluorescent Light Bulbs Replacing energy-wasting incandescent bulbs with CFL'S (Compact Fluorescent Light Bulbs) is an easy way to extend the life of your light bulbs while enjoying significant energy savings. It is estimated that Just one CFL can cut energy consumption by 75%. They're available in different shapes and sizes to fit almost any indoor or outdoor fixture.
Compact Fluorescent Light Bulbs last upto 10 times longer than incandescent bulbs. CFLs may cost more to purchase then old-fashioned incandescent light bulbs, but the resulting energy savings more than offset the difference. By using 50% to 70% less energy, CFLs mean lower utility bills for the user, less strain on the environment, and less global warming emissions.
Types of Compact Fluorescent Light Bulbs
TONES Tone simply describes the quality of any particular color. When describing the tone, such references are usually made:- Warm or cold Bright or dull Light or dim Pure or impure.
Shades This is a term used to describe colors that vary slightly from their standard colors due to a difference in hue, saturation or luminosity Hue-This is a base color at its full intensity. Saturation-This simply refers to the point when no more can be absorbed, combined with or added to. Luminosity-Refers to the movement of brightness on a surface and its effect.
TINTS Adding a small amount of one color or a white pigment to the same color or another one. The main aim of doing this is to make it brighter/lighter. The level of brightness depends on the amount of white pigments you add to the color. The downside of this is that if the white pigments exceed then you might lose the original color.
Though not scientifically proven, therapists and designers say that color is a major part of our daily lives as it elicits certain emotions, moods and even physical feelings.
WARM COLORS They are known to stimulate and excite. Should be used in areas where there should be activity and interaction. Examples of these places includes the living room and the kitchen. They include:- Reds Yellows Orange
cool colors They are known to have a relaxing and calming effect. Are mostly appreciated in rooms where the aim is mainly to relax like the bedrooms and bathrooms. They include:- Blues Greens Purples
References Architectural Standard – Donald Watson – Time Saver Standard for Architectural Design Data Handbook Of Interior Lighting Design Sun/Earth Buffering and Superinsulation page 68 ISBN