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Ceiling light fixtures

Modern central ceiling fixtures provide good levels of ambient light for almost any room. Some are fitted with an uplighter which can be made from glass, soft fabrics or plastics, this diffuses the light and disguises the light source. Ceiling light fixtures provide good general illumination, often referred to as ambient lighting. Luminaires for modular ceilings in combination with an appropriate ceiling assembly are referred to as luminous ceilings. In essence, ambient lighting provides a minimal amount of brightness, enabling people to move around and see each other easier. The contemporary light sources commonly used in luminous ceilings include tubular fluorescent lamps and compact fluorescent lamps without integrated ballast.
A ceiling light fixture can provide the finishing touch to any room and can be used in virtually any location from the living room and bathroom to the stairway and hall.

About modern + contemporary lighting

Light is life. Lighting level, light colour, modelling and changes from light to darkness impact on the rhythm of our daily lives, on our sense of wellbeing and on our mood.

Above all, however, light is the medium that enables us to see. 80 percent of the information we receive about the world around us is gathered by our eyes. Insufficient light or darkness prevents us getting our bearings and make us feel insecure. A sense of security at night is restored only when the darkness is banished by artificial lighting.

Over the centuries, the phenomenon of "light" has been studied and its mysteries explained by physics: light is visible electromagnetic radiation transmitted by a light source in waves. And it takes time to move from its point of origin to the eye of the observer. In a vacuum, light travels at a velocity of 300,000 km/s (speed of light). Each wavelength has a distinct colour appearance.

Contemporary Lighting and vision

We perceive the world around us through sense organs. And the most important sense organs of all are our eyes: they provide around 80 percent of all the information we receive about our surroundings. Without light, that visual perception is impossible.
A brief history of modern lighting

As long ago 300,000 years ago, human beings used fire as a source of warmth and light. Campfires – and later torches and oil or tallow lamps – brought light and life into caves in which sunlight could not penetrate.

As settlements developed, lighting found more and more applications outdoors. Around 260 BC, the Pharos of Alexandria harnessed light to send signals; in 378 AD, streetlighting seems to have been in use in the ancient city of Antioch.

Although oil lamps were mere utensils, they were decorated and designed for aesthetic appeal. In 1783, lamp development took a major step forward with the invention of the central burner. In the same year, a way was found to make gas from coal for streetlamps. In 1879, the age of the electric light dawned when Thomas A. Edison "re-invented" the light bulb invented 25 years earlier by the German clock-maker Johann Heinrich Goebel.

In recent decades, lamp and luminaire development has been particularly dynamic. Modern technologies, new materials and new optical systems are opening up new possibilities in artificial lighting - while at the same time maximising economic efficiency and minimising environmental impact.

Lighting and the environment

It is not only lighting itself that impacts on the environment but also the products that go into a lighting system. Environmental acceptability is thus an important quality criterion for manufacturers of lamps, electrical components and luminaires. Environmental issues addressed in recent years include lighting power consumption, lamp recycling, light pollution and the effect of artificial lighting on insects.

About ten percent of the total electricity consumption is used for lighting. Up to 80 percent is consumed by industry, commerce, public authorities and transport; just one fifth goes into private household lighting. So power consumption is not very high to start with, but every hour saved helps ease the pressure on the environment. It has been known since before the 1997 Kyoto climate protocol that emissions of the greenhouse gas carbon dioxide (CO₂) need to be reduced.

The energy-saving options offered by the lighting industry include long-life lamps with high luminous efficacy, efficient electronic control gear, luminaires and lighting systems with optimized optical control characteristics and means of incorporating daylight near windows into artificial lighting systems. The aims of these innovations since the introduction of the energy-saving lamp in 1981 are to maximize output (=light), minimize input (=electricity) and improve the quality of lighting.

A central role in economical lighting is played by lighting electronics. A great deal of lighting, particularly in offices and factory bays, is provided by linear fluorescent and compact fluorescent lamps. Here especially, the use of electronic ballasts (EBs) makes a valuable contribution to environmental protection. It also, of course, reduces operating costs in comparison with conventional lighting systems. And last but n ot least, EB operation makes for greater lighting comfort – because it permits tailored lighting which meets high ergonomic standards, promotes a sense of wellbeing and is good for our health.

At some point, even the most economical lamp comes to the end of its useful life. And it is important that it is properly disposed of. Where disposal is easiest is in the case of incandescent and tungsten-halogen lamps. Consisting of metal and glass, these light sources contain no environmentally harmful materials and can simply be disposed of as normal household waste.

Fluorescent lamps, however, do contain environmentally relevant substances, so they must not be disposed of as household waste. Nor should their bulbs be disposed of at glass recycling points. Although energy-saving lamps, compact fluorescent lamps, linear fluorescent lamps and other kinds of discharge lamps today contain only minute quantities of mercury.

What are recessed ceiling luminaires?

Luminaires for mounting in cavities or ceiling voids. Most of the luminaire is recessed in the ceiling and thus not visible. In many cases, the luminaire face is flush with the ceiling. See also Surface-mounted ceiling luminaires, Pendant luminaires.
What is illuminance?
Illuminance (symbol: E) is measured in lux (lx) and indicates the amount of luminous flux from a light source falling on a given surface. Illuminance is 1 lux when an area of 1 square metre is uniformly illuminated by 1 lumen luminous flux. Illuminance is measured on horizontal and vertical surfaces, using an illumination photometer. Where a white room and a dark room are provided with the same lighting, the white room appears brighter.

What is a glare?

Glare can be caused directly by luminaires or other surfaces with excessively high luminance, e.g. windows (direct glare). Direct glare is assessed by the UGR method. It can also be caused in directly by light reflecting from shiny surfaces (reflected glare). Glare impairs visual performance (physiological glare) and visual comfort (psychological glare).
What is uniform illumination?
For the performance of a visual task, it is important to ensure not only the right lighting level but also the right degree of uniformity in the way the brightness is distributed. The yardsticks for this are uniformity of luminance and uniformity of illuminance, each expressed as a ratio between lowest and mean or lowest and highest values.
What are luminaires?

The term "luminaire" refers to the entire electric light fitting, including lamp. Luminaires protect lamps, distribute their light and prevent it causing glare. Luminaires are differentiated on the basis of type lamp (incandescent, fluorescent, discharge lamps), number of lamps (single-lamp, twin-lamp, etc.) intended location (interior luminaires, exterior luminaires), degree of protection (luminaires for dry, damp and dusty interiors), type of construction (open luminaires, enclosed luminaires, reflector luminaires, specular reflector luminaires, louvered luminaires, diffuser luminaires, floodlights) and application (technical luminaries, decorative luminaires).

What are wall luminaires?
Wall luminaires are used for task lighting, as part of the general lighting in a room and as a source of supplementary, accentuating light. They generally belong to a luminaire "family" of uniform design.

What is colour rendering?

The colour rendering of a lamp indicates the effect its light has on the appearance of persons or coloured objects. This is rated by reference to the "general colour rendering index" R_a, which indicates how natural colours appear under a lamp's light. The colour rendering index is based on eight frequently found test colours. R_a = 100 is the best rating; the lower the index value the poorer the colour rendering properties. Lamps with an R_a index less than 80 should not be used in interiors where people work or spend lengthy periods of time.
What is a lamp?
No lamp, no light. The term "lamp" refers to an engineered artificial light source, e.g. incandescent lamp, energy-saving lamp, compact fluorescent lamp. Lamps are used in luminaires which distribute and direct the lamps' light and prevent it causing glare.
What are incandescent lamps?
Incandescent lamps are typical thermal radiators. They consist of an evacuated glass bulb containing a tungsten filament, which glows when heated by an electrical current to around 2,600 – 3,000 degrees Kelvin. Most of the radiation emitted is in the infrared range.
What are tungsten halogen lamps?
In terms of technical design and in the way they work, tungsten halogen lamps are similar to incandescent lamps. The gas with which they are filled, however, contains halogens or halogen compounds. Within a certain temperature range, these additives enable volatizing tungsten atoms to be redeposited on the filament and and thus prevent blackening of the bulb and the consequent decrease in luminous flux. This makes for higher luminous efficacy and a longer life compared with incandescent lamps. Also, owing to the much smaller dimension of the burner and filament, precise optical control is possible.
What is light colour/ warm white light?

Light colour describes the colour appearance of a lamp's light. Light colours are based on colour temperature expressed in degrees Kelvin (K):

warm white (ww) < 3,300 K

neutral white (nw) 3,300 K to 5,000 K

daylight white (dw) > 5,000 K.

Lamps with the same light colour can have different colour rendering properties. Light colour helps create the atmosphere of a room: warm white light is found cozy and comfortable; neutral white light creates a more businesslike atmosphere. Daylight white light is only suitable for interiors where illuminance exceeds 1,000 lux; where illuminance is lower, daylight white light makes the surroundings look pale and monotonous.