ARTIFICIAL LIGHTING .pdf

IMPACT OF ARTIFICIAL LIGHTING ON THE PERCEPTION

AND USAGE OF INTERIOR SPACES (TYPOLOGY: RETAIL SPACES)

SEMINAR REPORT

ANANT MUKATI / 2008BARC054. SEVENTH SEMESTER, APRIL.’12

DEPARTMENT OF ARCHITECTURE SCHOOL OF PLANNING AND ARCHITECTURE

BHOPAL December - 2011

DECLARATION

This is to certify that the Seminar entitled " IMPACT OF ARTIFICIAL LIGHTING

ON THE PERCEPTION AND USAGE OF INTERIOR SPACES

(TYPOLOGY: RETAIL SPACES) " submitted by me is a record of my own work

carried out under the supervision of Ar. KARNA SENGUPTA The matter embodied in this

seminar work, other than that acknowledged as reference, has not been submitted for the

award of any degree or diploma in this or any other institute.

School of Planning and Architecture Anant Mukati

Bhopal.

April – 2012

CERTIFICATE

It is certified that the declaration given above by " ANANT MUKATI " regarding his/her

Seminar work is true to the best of our knowledge.

Ar. Karna SenGupta Dr. Sanjeev Singh

Seminar Guide, Head of the Department,

Department of Architecture, Department of Architecture,

School of Planning and Architecture, School of Planning and Architecture,

Bhopal. Bhopal

Abstract

ANANT MUKATI 2008BARC054

Abstract The designer can create the most eloquent space, crafted in exquisite detail using finest materials in the most gorgeous colours, but, without light, he or she has wasted time, effort and money. Light and the effect of light are key to the enjoyment and functional successes of spaces. The way the light impinges on the highpoints of surfaces, and the shadow created by its absence, allow us to perceive form and texture. It is the light that allows us to discern differences in colour and tone. The painterly use of artificial light, experimented in this report, can be employed by the Architectural Designers to create a mood appropriate to the particular brief, space and retail interiors. Until man learnt to artificially replace it, the fundamental source of light was the sun and in many respects sunlight remains the platonic ideal of light : its varying strength, colour values and direction bringing liveliness to the environment, changing through the day and from season to season. It would be an unusual building, with unusual inhabitants, that was capable of using natural light alone, and virtually all buildings with which interior architects work employ artificial illumination to replace or supplement natural light. Over the centuries tapers, candles and oil lamps have given way, first to gas light and ultimately to the various forms of electric light. Each had a particular character, qualities and problems. In the design of interior environment we are often endeavouring to replicate the positive aspects of the system and products while minimising or overcoming the shortcomings. This is as true as lighting system of any other. By identifying the needs and developing a lighting design ethos that marries the requirement of space, activity and mood, it is possible to specify a lighting system that at one extreme may mimic the intimacy of candlelight and at the other provide the lighting levels and even distribution of different retail product category, with ever conceivable variant in between. In fact with the different combinations of light it is possible to create lighting that can modify the mood and the capabilities. In practical terms artificial light is indented to do one of the following things.

• To provide the sole means of illumination at night • To augment the light provided by the window in order to provide better modelling • To provide light to compensate for poor natural lighting in winters or in poor weather

conditions • To provide supplementary lighting when rooms are too deep for adequate natural

lighting. The objective In architecture, light is tremendously vivid and manifold. Intelligently positioned and well- dimensioned, light is able to generate a terrific intensity. Light can stir up emotions and help bind them to loved experience. When it gets dark, human beings undergo a change of mood. At these times good light is always in demand. The art of lighting design consist of the ability to bring out even extreme and unusual features. Beauty and harmony makes an impression, the same as inevitable conflict and the grotesque. Light must appeal to everyone, but it must also have a situational effect for individual, couples or groups. Good light continually rewards the fine line between harmonious variety and sharp contrast.

Index


Cover

Certificate

Acknowledgement

Abstract

Index

Chapter 1 Introduction to Artificial light

1.1 Why Artificial lighting? 1.2 History of Artificial Lighting 1.3 Types of Artificial lighting

1.3.1 Incandescent lamp 1.3.2 Compact fluorescent lamp 1.3.3 Fluorescent tube 1.3.4 Gas Discharge lamps 1.3.5 Light Emitting Diode (LED) 1.3.6 Halogens

1.4 Modern lighting system

Chapter 2 Science behind light

2.1 Introduction 2.2 Properties of light 2.3 Lighting level for different human comfort

Chapter 3 Retail Spaces & Artificial lighting

3.1 Introduction 3.2 Aim 3.3 Objective 3.4 Scope 3.5 Limitations 3.5 Methodology

Chapter 4 Important Lighting Design Criterias 4.1 Illuminance Levels

4.2 Maintenance Rate 4.3 Balanced Luminances 4.4 Limitation Of Glare 4.5 Direction Of Light And Shadows 4.6 Colour Of Light 4.6.1 Colour Of Light 4.6.2 Colour of Surfaces 4.6.3 Colour Rendering

Index


Chapter 5 Existing Retail Spaces 5.1 Case Study -1 : Volkswagen Bhopal

5.1.1 Introduction 5.1.2 Methods Adopted for Study 5.1.3 Observations 5.1.4 Principal Findings

5.2 Case Study -2 : Agarwal saree

5.2.1 Introduction 5.2.2 Methods Adopted for Study 5.2.3 Observations 5.2.4 Principal Findings

5.3 Conclusions

Chapter 6 Future trends of study 6.1 Photometric studies 6.2 Automated lighting control 6.3 Light pollution 6.4 Strategies for Energy Efficient Lighting

Selected Bibliography

Annexure

Impact of Artificial Lighting on the Perception and Usage of Interior Spaces (Typology: Retail Spaces) 1


1

Introduction To Artificial Light

1.1 Why Artificial lighting? Artificial light has made much of human development possible. Since the discovery of fire, light plays a central role in our lives, extending our hours of life, creating mood and atmosphere in our homes, and increasing our productivity.

Since the rising concerns in the last century about the electricity use of traditional incandescent light bulbs, the mainstay of our post-industrial lighting solutions, there have been many alternatives brought to market. Some of these are excellent replacements for the standard lightbulb in most cases but others are not such great alternatives. 1.2 History of Artificial Lighting The Evolution of Artificial Light, shows how artificial light and its twin invention, electricity, have in one way or another shaped everything that we have become. The artificial light follows the path of this catalyzing technology as it winds it way from the last Ice Age into present day. Early humans using stone lamps for painting the walls at Lascaux, to the whaling trade as it arose to supply the world with lamp oil, to Edison’s Menlo Park and the dawn of modernity, to the massive power grids of today, a story of evocation begins to emerge. What that form is has yet to reveal itself, but its effects have probably been best described by Marshall McLuhan in 1964 when he wrote in Understanding Media, “The electric light escapes attention as a communication medium just because it has no ‘content’. And this makes it an invaluable instance of how people fail to study media at all. The message of the electric light is like the message of electric power in industry, totally radical, pervasive and decentralized. For electric light and power are separate from their uses, yet they eliminate time and space factors in human association exactly as do radio, telegraph, telephone and TV, creating involvement in depth.” The twin needs of profit by commercial interests and convenience by consumers drove the expansion of light from the earliest days of the candle to today’s ubiquitous power lines. Curiously, destruction of the natural world seems to walk hand in hand with the evolution of artificial light, and its Siamese twin, electricity. From hunting sperm whales almost to extinction in the 1800s, to polluting the air and killing miners for coal to power yesterday’s gas lamps and today’s “modern” power grid, the history of artificial light and electricity contain a hidden undercurrent of turning inwards, of staying inside, of looking towards a lit screen, of fear and alienation. Through artificial light and electricity we have unintentionally created our own world, free from the natural rhythms of the earth, and even our own bodies.



We live in a world where the origins of the most basic objects have become mysterious. Being at the end of such a long chain of cause and effect, even the most intelligent and encyclopedic among us usually don’t know the history of the simplest, everyday objects; things like light bulbs or the electricity that we use utilize for almost every activity of our lives/

1.3 Artificial lighting sources The type of light is determined by the technology used to produce the light. There's dozens of types, with a few common in household applications and others more suitable for industrial uses. The five most common light types in household lighting applications are incandescents, halogens, compact fluorescents, LED's and a few gas-discharge lamps.

In addition to this there are a few solutions that work on sunlight, which are preferrable over most artificial light sources, if they are applicable. The most common ones are reflectors and light tubes, but there are also materials which can store sunlight and emit it at night, for instance. 1.3.1 Incandescent lamp

Incandescents are the lamps that have illuminated our world for centuries. There are various inventors of incandescent lamps, but it's usually credited to Thomas Edison in 1880, because he invented the long-lasting tungsten filament. We know incandescents most commonly as the standard light bulb, but incandescents exists in a very wide range of shapes, forms, voltages, colors and applications. They produce a great spectrum, with very poor energy efficiency and a short life span.

Incandescents produce light by flowing power from the wall socket directly through a very thin filament of Tungsten, which then glows, in a glass chamber that protects the filament from coming into contact with air, which will cause the filament to burn up in seconds otherwise.

Incandescent bulbs are cheap to make and buy, have a very good spectrum, consistency and color rendering, produces a lot of heat, and are therefore very energy inefficient. They have a very short life span, and need to be replaced often. 1.3.2 Compact fluorescent lamp The compact fluorescent lamp (CFL) was designed as a more efficient replacement for incandescent lamp. It is supplied with the same fixing system (screw or bayonet), and can be used in many light fittings designed for incandescent lamps. Power ratings of CFLs that can

Source : http://www.except.nl/consult/

artificial-lighting-guide/index.htm#1



provide approximately the equivalent light output to incandescent lamps are shown in the table below, together with their efficacy ratings.

1.3.3 Fluorescent tube Fluorescent tubes are the main form of lighting for offices and commercial buildings. They are a form of gas discharge lamp, and are formed in a long thin glass cylinder with contacts at either end that secure them to the fitting (or luminaire) and provide the electrical connection. The tube contains mercury vapour at low pressure, and the inner wall of the glass is coated with a phosphor that reacts to ultra-violet radiation. When electricity is passed through the vapour it emits UV radiation that is converted by the phosphor to visible light. The most efficient fluorescent tubes are the T5. With a smaller diameter (16mm) than earlier tubes, these can achieve a luminous efficacy of up to 104lm/W.

Source : Google Images

1.3.4 Gas Discharge lamps Gas-discharge lamps work by sending a current through an ionized gas. We all know Neon lights from the colorful street signs, which are a type of gas-discharge lamp, but there are a great many other types, some of which have very useful properties.

Some gas-discharge lamps contain mercury (mercury vapor lamps, usually blue in color) so be careful with those, because mercury is a very poisonous material (see material use).

Source : http://www.except.nl/consult/artificial-lighting-guide/index.htm#1



Some interesting gas-discharge lamps for household applications are low pressure sodium lamps, which can be used well in outdoor situations where illumination is wanted, but color is not important, such as lighting of a car-park. These are yellow-amber in color and have very poor color rendering. However, they are very energy efficient, sometimes up to 200 lumens per watt, beating every other light type available far and wide in energy efficiency. For uses where a lot of light is desired, the color irrelevant and high efficiency relevant, these could be a very good choice. Note should be taken that they do have a short warm up time.

Low pressure sodium lamps are widely used as street lighting in various countries. It is also the lamp of choice to prevent outdoor light pollution, as its peak spectrum seems to be least harmful to life and ecosystems. Save for turning lights off, of course, which is still better.

1.3.5 Light Emitting Diode (LED) There are a few different LED types. We all know LEDs from the thousands of uses they perform as tiny signal lights on our stereo, phones, and other electric equipment. They are mostly semiconductor devices that operate on low voltage DC currents mostly, often requiring an adapter. Because they are semiconductors, LEDs are quite sturdy and less likely to break if dropped or due to harsh conditions compared to other lamps. Their life span is very long, some are rated up to 50.000 hours.

LEDs used to only be available in red, green, yellow and white, with the blue type only becoming available much later. These signal LEDs (image below) are not suited for general lighting applications, because they are not very energy efficient and their spectrum tends to be ill suited for general lighting.

It's been only recently that LEDs have been developed that provide decent general lighting. While the first attempts at producing generic LED lighting solutions proved to be somewhat disappointing -with many LED lights having extremely poor spectrum and lower than expected efficiency ratings- today there are ample high quality LEDs available that outperform most other light types in most areas. They are energy efficient, consistent, sturdy, have the longest life span of all consumer lights and can have very good light quality.

The most common ailment of LEDs, especially cheap ones, are spectrum and color rendering, so keep an eye out on that. The light 'spread' may also suffer in cheap models. Also, for a long time it was not possible to produce LEDs that emitted enough light to replace a 60Watt incandescent light bulb. This is now also no longer a problem. LEDs tend to be a bit pricey, especially the quality kind. However, once you buy one, and don't, let's say, throw it around the room, it should last you a life time, providing great economy and worry free lighting.




As with CFLs, LED lamps by default cannot be dimmed, but there are models available that do.

Besides semi-conductor LEDs there are recent developments in Organic LEDs (OLED) and polymer LED (PLED) technology that are quite promising.

1.3.6 Halogens Halogens are incandescent lights where the gas chamber is filled with a halogen gas type, allowing the light to operate at higher temperatures, last a bit longer, and be more compact.

Halogens tend to be somewhat higher in performance than normal incandescents, with slightly higher efficiency, and a longer life span, but typically cost more. Halogens are also made in more accurate production processes that allow very specific models and light spreads to be made. Therefore, high quality spot lights tend to be halogen lights. Because of their excellent color rendering and spectrum, halogens have been the lamp of choice for demanding light applications in the home, office, laboratories and elsewhere.




1.4 Modern lighting fittings

The fitting into which a light source is installed is an important consideration in achieving energy efficiency. The Fittings for fluorescent tubes are called luminaires and come in a variety of types, suitable for different applications.

The important consideration in selecting a fitting is to achieve maximum efficiency without compromising the quality of light. This requires a fitting that transfers as much light as possible from the lamp to the working surfaces, without resulting in direct glare, veiling reflections or excessive brightness ratios. The important features of a luminaire are the reflector and the lens. Common types of luminaire are described below.

Channel luminaires

This simplest form of luminaire is simply a tube holder with a white reflector. This has a high efficiency, but can result in glare problems since the lamp is visible.

Prismatic diffuser.

This uses an acrylic prismatic diffuser to conceal the lamps, resulting in low surface brightness, reducing glare problems. It is not very efficient, due to light losses in the diffuser.

Parabolic louver.

This provides excellent glare control without compromising efficiency, using reflective aluminium louvers to conceal the lamps from low viewing angles.

Uplighter.

In this system the lamp is concealed by a reflector that directs the light onto a curved reflector that in turn directs it down into the room.




Source : Revision 1 September 2007, Section 9 Lighting – Artificial And Daylight, Energy Efficiency

Building Design Guidelines for Botswana



2

Science Behind Light

2.1 Introduction Visible light is electromagnetic radiation with a wavelength that is visible to the eye. Light has an intensity that is determined by the amplitude of the radiation, and determines the perception of the brightness of the light. It also has a wavelength or frequency that determines the colour. Light may include a range of different frequencies or colour, and sunlight includes the full spectrum of visible light (as well as frequencies beyond the sensitivity of the eye, known as ultra violet and infrared).

The intensity of light (or luminous flux) is measured in lumen (lm). This is the unit used to measure the amount of light emitted by a light source.

Illuminance is a measure of the intensity of light falling on a surface. It is measured in lux (lx) that has units of lumen per meter squared (lm/m2). This is the unit commonly used to specify the level of lighting required on a surface for different activities.

The efficiency with which a light source converts electrical energy into light is know as its luminous efficacy and is measured in units of lm/W, where lm is the luminous flux emitted by the source, and W is the electrical power consumed.

A luminaire is the fitting that a light source is installed in. The efficiency of a luminaire is known as the luminaire efficiency (or light output ratio), and is the ratio of the luminous flux emitted by the luminaire and the luminous flux of the source or lamp.

As important as the quantity or brightness of light is the quality. The three main problems that compromise the quality of light are glare, veiling reflections or excessive brightness ratios. Glare Glare is experienced when a bright light source such as a lamp, the sun, or the reflection of a light source is in a person’s field of view. Veiling Reflections Veiling reflections are caused by bright light sources reflected from a task surface, such as a book. Brightness Ratio When moving from indoors to outdoors on a clear day, one experiences a very large change in brightness. This is unpleasant for a short period of time during which it is difficult to see detail. Then the eye adjusts to the new level of brightness and can see well again. The problem occurs when there are surfaces within the same space with large differences in brightness. Brightness ratio is the ratio of the brightest surface to the least bright.



2.2 Properties of light To understand some aspects of artificial lights, it's good to investigate some properties of light in general. There are basically only two properties of light in general that concern us: intensity and spectrum. Together these define the light we care about. Intensity is rather self-explanatory: the amount of light emitted. Light is defined as that part of the electromagnetic spectrum that can be seen by an average human, and is a subset of this energy. Intensity of light can be measured in Lumens, and Lux, where Lux is Lumen spread over a certain area. Lamps are usually expressed in Lumens. More on that later. Spectrum The spectrum of light defines the set of wavelengths present in the light in question. Sunlight contains the 'full spectrum', but also includes infrared, ultraviolet and other radiation beyond those wavelengths. Even though sunlight contains the full spectrum of visible light, it does not contain an equal amount of all wavelengths. The below diagram shows an approximation of the spectrum and intensity of direct sunlight. Diagram of the solar spectrum. Note that a large amount of energy (area underneath the curve) is present in infrared. The curve in this diagram is called a 'spectrum-curve'. This corresponds to the perception of sunlight as 'warm' light, since it has higher intensities in the red spectrum than in the others. The diagram shows light received by earth at atmospheric level, but not necessarily what reaches your exact location. Light is filtered through various atmospheric layers before it hits the ground. This varies per location and with atmospheric conditions. On an overcast day, when clouds filter certain wavelengths of light from the sunlight, the spectrum looks different. Generally speaking, we can say that daylight on a cloudy day has a more even spectrum-curve. This means the distribution of light intensity per spectrum section is more even, which increases our ability to perceive colors neutrally. This is important, for instance, if you want to judge the color of a certain set of house paints. Doing it on an overcast day will allow you to see the colors better than in direct sunlight, also because of less glare. The same goes for prints and other color sensitive applications. 'Daylight' is usually considered to be the direct light of the sun, plus that light which is scattered by the atmosphere (indirect). This indirect light enables us to see in areas where no direct light is present, as well as bouncing of light off of neighboring surfaces.



Energy If we understand that electromagnetic waves are a form of energy, we understand that radiation in the infrared and ultraviolet ranges also contain energy, eventhough we cannot perceive them with our eyes. Infrared is generally perceived as heat, and ultraviolet as invisible radiation that may damage our health (UV radiation) but is also used for certain useful purposes by other animal species, such as by bumblebees for navigation. It should also be said that we don't fully understand all the effects of the electromagnetic spectrum on biological life. We do know that it's of vital importance to almost all living things and that life on earth has evolved in iteraction with the spectrum of our sun.

Why is this important if we want to learn about artificial light sources? There are various clues to be found in this as to the effects of various light fixtures that may not be easily explained from a purely technical perspective. In addition, understanding that visible light is just a subset of the electromagnetic spectrum is important to understand if you're looking for light sources that both perform well and are energy efficient.




2.3 Lighting level for different human comfort

Lighting an environment is often a complex task principally considered during the design

stage of the building (by architects and interior designers). However, lighting should be designed for the tasks that individuals are carrying out within that environment. Guides to lighting can seem very complex, technical documents. However, employers can take some simple steps to ensure people have adequate lighting to carry out their tasks.




3

Retail Spaces & Artificial Lighting 3.1 Introduction Shopping is an activity that is a part of our everyday life, whether we are shopping for ourselves or simply out of enjoyment, the places we choose to shop say something about our lifestyle, culture and interests. We create a relationship with the retail environment we feel comfortable with and reject spaces that do not match our image.

The design of retail shops is an ever-changing cycle, following fashion trends and consumer aspirations. Retail spaces are at the forefront of contemporary interior design because these are updated frequently to stay competitive and appealing. Some of the most innovative and interactive interiors can be seen in the retail sector.

Designing retail interior is complex. The aim of the designer is to entice and excite the consumer by creating an experience to which they can relate. Artificial lighting is a key tool to solve this purpose. It plays a vital role in using or avoiding a space within a retail shop. This seminar is aimed to gain an experience and knowledge of use of artificial lighting and experimenting them in design of interiors of our retail spaces. 3.2 Aim An attempt to integrate and understand artificial lighting into our retail spaces through appropriate architectural interventions. 3.3 Objective To study and define artificial light as the organizing principles for interior spaces. Study the relationship of human perception with the colour, location and type of artificial

light source and validate the same. To identify positive and negative aspects of artificial light over different corners of a

retail space through architectural intervention. To study the existing retail spaces and analyzing the same. To intelligently distribute the light density to highlight particular corners of the retail

spaces through experiments and analysis. 3.4 Scope Study of artificial lighting system and their effect on consumers in existing retail spaces. Evolving architectural design principles for retail shops to facilitate a versatility of

artificial lighting system to meet the changing demand and completion of the retail world.



Obtaining a different light mood with the mix of two or more different colour light. 3.5 Limitations All the case-studies are considered to be ideal designs and inferences would be drawn

accordingly. No attempts would be made to revitalize any of the retail spaces.

3.5 Methodology



4

Lighting Design Criteria

4.1 Illuminance Levels

A luminous flux hitting a surface causes a certain illuminance level. According to our visual perceptions we are only able to see the redirected portion of this light which is closely connected with the surface’s reflectance.

The higher the value of the reflectance, the brighter the surface appears. Although luminance plays a dominant role, it is difficult to measure and it often depends on the angle of view.

That’s why national institutes and international organisations recommend certain illuminance values that should be achieved throughout use.

Illuminance value E: It is the quotient of the luminous flux by the area of the surface.

Rated illuminance EN : The rated illuminance lists the illuminance value for a certain task that must be achieved on average all the time in the room (or working area).

According to DIN 5035, the position of the plane, where the rated illuminance is measured, depends on the room’s use.

In traffic zones like corridors the plane is positioned 20 cm above the floor. In offices the working area is at the height of a desk. Therefore, the plane is positioned 85 cm above the floor.

Position of the plane

The more difficult the visual task, the higher the rated illuminance.

The emitted luminous flux of luminaires drops continuously from the moment of installation. A number of reasons can be mentioned, lamp lumen depreciation during life as shown previously and dirt on luminaires are of particular importance.

To guarantee that a minimum value is achieved during time of use, the initial illuminance value should be increased. According to the amount of the expected light loss given through a certain light loss factor v, a planning factor p is defined. The reciprocal relation between planning factor p and light loss factor v is given through the expression

p = 1 / v

The amount of light loss depends on the luminaire ’s location and is affected through the use of the room (interior lighting - exterior lighting, factories - offices...).

The following table lists light loss factors for common exposure to dust and dirt including standard lamp lumen depreciation:

Planning factor for the dirt exposure of luminaires



The above mentioned standard DIN 5035 recommends a light loss factor of v = 0.8 which corresponds to a planning factor of 1.25. This causes an initial increase of 25 % of the average illuminance. During operation, the luminaire´s light output decreases continuosly.

The moment the average illuminance level is 80% of the rated illuminace, the standards recommends refitting lamps and cleaning luminaires.

To prevent this average value from leading to too dark areas and from causing safety defects (i.e. in case of the failure of neighbouring lamps) it is also recommended that the illumination level reach 60% of the rated illuminance at all times. This is an absolute minimum value.

4.2 Maintenance Rate

Reality shows us that just by means of maintenances illumination levels reached at the moment of installation cannot be perpetuated during operation. Thus, times of relamping and maintenance periods should be used to eliminate all negative influences that occur during operation.

Therefore it is meaningful to increase the planning factor in cases of dusty surroundings and in difficult maintenance situations (i.e. difficult access, height,...). This increases the periods of maintenance that is particularly important when maintenance costs are high.

If the average illuminance value on a working place falls below 0.8 times the rated illuminance or if the minimum illuminance value falls below 0.6 times the rated illuminance maintenance is recommended.

4.3 Balanced Luminances

The luminances of surfaces we perceive are caused by the reflected luminous flux that reaches our eyes. The luminance values depend first, on the absolute level of the illuminance and second, on the surface’s reflectance value.

If a certain level of illuminance is recommended (rated illuminance), a certain amount of luminous flux is necessary. Thus the luminance can only be modified by changing the reflectance value of the surface, which means the replacement of materials.

Thus, the lighting designer is able to achieve a balanced luminous environment within the field of view by choosing materials with certain reflectance values. Reflectance values mostly correspond with certain colours of surfaces. That means the luminous environment can be adjusted by changing the colour of walls, ceiling, floor and desks. This is one of the many examples that demonstrate the close connection between lighting designer and architects.

Concrete absolute luminance values how to generate a balanced luminous environment can not be given in general. It depends on the use of the illuminated area.



4.4 Limitation Of Glare

We differentiate between direct glare and reflected glare

Direct glare: is glare resulting from high luminances or insufficiently shielded light sources in the field of view. It is usually associated with bright areas, such as luminaires, ceilings and windows that are outside the visual task or region being viewed.

Reflected glare: is glare caused by the specular reflection of high luminances in polished or glossy surfaces in the field of view. It is usually is associated with reflections from within a visual task or area in close proximity to the region being viewed.

Direct glare versus reflected glare

Furthermore, both kinds of glare mentioned above can cause disability glare or discomfort glare. Disability glare results in reduced visual performance and visibility. It is often accompanied by discomfort glare that does not interfere with visual performance or visibility.

Source Wilfried Pohl & Andreas Zimmermann, SynthLight Handbook Chapter 3: Artificial light

4.5 Direction Of Light And Shadows

The direction of light depends on the luminous intensity distribution of each single luminaire and its location in the space. The direction of light determines if shadows appear and which intensity they might have.

Areas illuminated completely diffusely, thus with no shadows, interfere with our spatial perception. Furhermore, such spaces give the impression of monotony and lead to premature tiredness. A body with the same colour as its surroundings is not visible without shadows. In such illuminated areas information gets lost.

Nevertheless, a certain amount of diffuse illumination is important and should be generated through ambient lighting. The diffuse component contributes to vertical illuminances which are necessary to recognise the faces of people walking through corridors.



This project objective can be achieved by illuminating or washing ceilings and walls using luminaires with wide angles of radiation. Well-balanced shadows generating soft transitions are appropriate - strong shadows due to concentrated beams should be avoided.

Of course, limitation concerning luminance values, as discussed in previous chapters, must be taken into consideration.

Direct illumination usually has to provide the required amount of illuminance. By limiting its angle of radiation these luminaires should generate shadows creating structure and three-dimensionality. Point sources and reflector design providing narrow radiation are useful tools to meet this design goal.

In offices, further demands on the incidence of light are made. According to typical tasks performed in offices, the direction of light should not generate shadows on the task area (i.e. paper or desk) due to the worker´s position. Therefore, illumination from behind the person is absolutely forbidden.

If daylight penetrates the office, the direction of artificial light should be the same as that of daylight. Therefore illumination systems are needed which are mounted near windows and distribute light according to special lighting design requirements (i.e. to achieve high utilisation factors, radiation through the window to the outside must be avoided).

Although this complicates the reflector design it guarantees homogenous lighting conditions especially in the case of supplementary lighting at dawn (twilight).

4.6 Colour Of Light

The colour of light sources and the colour of space-defining surfaces has a great influence on the lighting environment. According to the perceived luminance, colour perception also depends on the interaction of many complex factors such as

light source (i.e. spectral distribution of emitted light)

characteristic of the object’s properties (reflectance...)

the direction of incidence (i.e. refractive prisms...)

the surrounding (i.e. colour of space defining surfaces...)

the observer’s adaptation (i.e. illuminance level)

4.6.1 Colour Of Light

The colour of light depends on the spectral composition of the emitted radiation. The spectral composition can be demonstrated by penetration through refracting prisms.

The colour of light is expressed verbally and in values of temperature. Values of temperature are used because the colour of light, which should be described, is compared to the colour of light which is emitted from a (black-) body at that temperature.



The colour of light is usually divided into three different groups:

Source Wilfried Pohl & Andreas Zimmermann, SynthLight Handbook Chapter 3: Artificial light

The higher the temperature, the more blue and white the colour looks like. The lower the characterising temperature value, the more red the light looks like.

A mistake, often made by laypersons, is to combine high colour temperatures with warmth causing a comfortable, pleasant and cosy environment. Such atmospheres can be generated with light sources with a lower colour temperatur in combination with lower illuminance levels. On the other side, the higher the colour temperature of the lamps, the more technically the space looks like and the higher the required illuminance level.

4.6.2 Colour of Surfaces

People respond to the colours they see in their environment, the colour affects their performance, positively or negatively, consciously or unconsciously.

The longer people are exposed to a visual environment, the better the surfaces have to be defined. Thus, this must be considered especially in offices.

Small offices can be made to appear larger, if wooden elements and furniture placed against walls have a similar reflectance. Contrasting colour might be used for chairs, sofas or in pictures. At lower illuminance levels, living spaces may appear better defined by creating more colour contrast.

To achieve well composed colour contrast, personal preferences should be discussed with interior designers and architects.

Nevertheless, especially in offices, all solutions should meet the requirements concerning balanced luminance ratios.

4.6.3 Colour Rendering

Colour rendering is a general expression for the effect of a light source on the colour appearance of objects in comparison to their colour appearance under a reference light source. The latter is very important concerning colour rendering. The colour appearance of one body (surface) can be changed completely by using different light sources. Thus, daylight is used as the reference source of high colour temperatures; incandescent light is used as the reference source of low colour temperatures.



5

Study of Existing Retail Spaces

5.1 Case Study -1 : Volkswagen Bhopal 5.1.1 Introduction Shirani Automotive Pvt. Ltd., Ahmedpur, Hoshangabad Road Bhopal Volkswagen is one of the world’s leading car companies and is on the pace of extending its market thought India. Establishing its showroom at Hoshangabad road in the year 2009, is the only Volkswagen showroom in Bhopal. 5.1.2 Methods Adopted for Study Following methods were adopted for the purpose of study of Impact of Artificial lighting on the perception and usage of the showroom interiors from the perspectives of customers and users of the showroom. Personal Observations Photographs Interaction with users and customers of different age groups Self interpretation over the basic lighting design criteria’s

5.1.3 Observations The Volkswagen Bhopal unlike the traditional car showrooms of Bhopal has a perpendicular car variant display to the front showcase (in traditional car showrooms of Bhopal the car variants are displayed parallel along the front show case glass). This was the first eye catching experience. Secondly the showroom was of small size (100 mts approx) unlike the other Indian car company’s showrooms in Bhopal. A probable reason would be that its a new and foreign car brand for the peoples of Bhopal. 5.1.4 Principal Findings It was a moon-white coloured artificial lighting in the showroom as per the Volkswagen

showroom theme. The probable reason that the white colour is a mix of all colours of the visible light spectrum and under its effect the actual car colour could be rendered to the customer.

All the lighting was from the roof and was hidden under the roof plane. The lighting was a grid of alternate halogen and CFL lights such that no two adjacent lights were

of same type. The lightings were fixed in steel holders to increases the reflectance. Few advertisement boards over the interior walls were provided with internal tube-lights to get

a diffuse effect.



Following were the findinds over the basic lighting design criteria’s :- Illuminance Levels

The showroom space was well illuminated from the eye level view (visual plane) with a cool moon-white coloured artificial lighting which would please any costumer.

Maintenance Rate The indoor lighting was very rarely cleaned. As in general practice there was no pre-defined or particular period for replacement of interior lights. The individual lights were only replaced when they get fussed or black-burns.

Balanced Luminances There was well balanced luminance throughout the showroom. The walls and the roof were made up of diffused white colour material and the floor of the showroom was covered with off-white high reflectance tiles. This set up brings the Car (Product) in the foreground of the consumers eye-level. Moreover the workspace and the display spaces were distinguished by using different floor materials.

Limitation Of Glare Since all the lighting was hidden under the roof-plane, so there was no direct glare from any light source. Moreover the wall surfaces were diffused. The major reflected glare was from the Car’s surface to highlight it as a product and a little reflected glare from the showroom’s floor which added the beauty to the place. Also to avoid the daylight (sun) glare from the large font glasses, the area adjacent to the glass is used as a circulation space and not for the product display.

Direction Of Light And Shadows The lighting was incidented vertically over the cars creating a diffused shadow just at its beneath. This shadow was more supported by the less reflecting floor surface.

Colour Of Light : Moon-white coloured light established a cool and pleasant environment.

Colour of Surfaces : The walls and roof were of diffused white colour and the floor was of off-white reflecting surface. Colour Rendering : When the white light from over the top incidented over the car’s surface, the car’s true colour, curves and features were reflected.



Volswegan Showroom Exterior Illumnance level

Balancing luminance Through Different limiting outside glare using transition space

Floor Materials

CompactFluorescent Lamp (CFL)

Halogen Light

Colour Rendering Light and Shadow



5.2 Case Study -2 : Agarwal saree G M Tower , 10 No Market , Arera colony Bhopal 5.2.1 Introduction Agarwal Saree is situated a t 10 No. Stop, Arera Colony, Bhopal. It has been earning trust of peoples of Bhopal from last 25 years and is one of the core saree stores of New Bhopal. It is the only store and had no other branches. 5.2.2 Methods Adopted for Study Following methods were adopted for the purpose of study of Impact of Artificial lighting on the perception and usage of the showroom interiors from the perspectives of customers and users of the showroom. Personal Observations Photographs Interaction with users and customers of different age groups Self interpretation over the basic lighting design criteria’s

5.2.3 Observations The showroom was of size 20 mts approx and the space was self-sufficient for functioning of a showroom. 5.2.4 Principal Findings It was yellow coloured artificial lighting in the showroom . All the lighting was from the roof and was hidden under the roof plane. The lighting was a grid of alternate halogen and CFL lights such that no two adjacent lights were

of same type. The lightings were fixed in steel holders to increases the reflectance.

Following were the findings over the basic lighting design criteria’s :- Illuminance Levels

The showroom space was well illuminated from the eye level view (visual plane) with a bright yellow coloured artificial lighting which highlights the shops interiors to catch anyone’s attention from outside.

Maintenance Rate The indoor lighting was very rarely cleaned. As in general practice there was no pre-defined or particular period for replacement of interior lights. The individual lights were only replaced when they get fussed or black-burns.

Balanced Luminances There was well balanced luminance throughout the showroom. The walls were mostly covered with furniture with yellow coloured ply-boards and the roof was made up of



diffused white colour material. The floor of the showroom was covered with off-white high reflectance tiles.

Moreover the blank walls were covered with mirrors to increase luminance level and also to extend the vision beyond the showroom’s boundary.

Limitation Of Glare Since all the lighting was hidden under the roof-plane, so there was no direct glare from any light source. Moreover the wall surfaces were diffused. The major reflected glare was from the glass tables used to highlight the saree inside it as a product and a little reflected glare from the showroom’s floor which added the beauty to the place. Also to avoid the outside and daylight (sun) glare from the large font glasses were used for product display.

Direction Of Light And Shadows The lighting was incidented vertically over the sarres creating a diffused shadow just below eliminating the monotony of the showroom.

Colour Of Light : Yellow coloured light established a warm and happening environment for shoppers.

Colour of Surfaces : The walls was of diffused yellow colour and the floor was of off-white reflecting surface. The roof was pure white diffused surface. Colour Rendering : When the bright yellow light from over the top incidented over the saree’s, the work over them was dramatically highlighted.



Agarwal Saree Showroom Exterior Iluminance Level

Limiting Outside Glare Reflected Glare From Glass Table

CompactFlorescent Lamp (CFL)

Halogen Light

Colour Rendering Use of Mirror on Wall



6

Future Trends of Study 6.1 Photometric studies

Photometric studies (also sometimes referred to as "layouts" or "point by points") are often used to simulate lighting designs for projects before they are built or renovated. This enables architects, lighting designers, and engineers to determine whether a proposed lighting setup will deliverer the amount of light intended. In many cases these studies are referenced against IESNA recommended lighting practices for the type of application. Depending on the type of area, different design aspects may be emphasized by IESNA for safety or practicality (i.e. such as maintaining uniform light levels or highlighting certain areas). Specialized software is often used to create these, which typically combine the use of two-dimensional digital CAD drawings and lighting calculation software (i.e. AGi32).

6.2 Automated lighting control

Building automation and lighting control solutions are now available to help reduce energy usage and cost by eliminating over-illumination. These solutions provide centralized control of all lighting within a home or commercial building, allowing easy implementation of scheduling, occupancy control, daylight harvesting and more. Many systems also support Demand response and will automatically dim or turn off lights to take advantage of DR incentives and cost savings.

Many newer control systems are using wireless mesh open standards (such as ZigBee), which provides benefits including easier installation (no need to run control wires) and interoperability with other standards-based building control systems (e.g. security).

In response to day lighting technology, daylight-linked automated response systems have been developed to further reduce energy consumption. These technologies are helpful, but they do have their downfalls. Many times, rapid and frequent switching of the lights on and off can occur, particularly during unstable weather conditions or when daylight levels are changing around the switching illuminance. Not only does this disturb occupants, it can also reduce lamp life. A variation of this technology is the 'differential switching or dead-band' photoelectric control which has multiple illuminances it switches from so as not to disturb occupants as much.

Occupancy sensors to allow operation for whenever someone is within the area being scanned can control lighting. When motion can no longer be detected, the lights shut off. Passive infrared sensors react to changes in heat, such as the pattern created by a moving person. The control must have an unobstructed view of the building area being scanned. Doors, partitions, stairways, etc. will block motion detection and reduce its effectiveness. The best applications for passive infrared occupancy sensors are open spaces with a clear view of the area being scanned. Ultrasonic sensors transmit sound above the range of human hearing and monitor the time it takes for the sound waves to return. A break in the pattern caused by any motion in the area



triggers the control. Ultrasonic sensors can see around obstructions and are best for areas with cabinets and shelving, restrooms, and open areas requiring 360-degree coverage. Some occupancy sensors utilize both passive infrared and ultrasonic technology, but are usually more expensive. They can be used to control one lamp, one fixture or many fixtures.

6.3 Light pollution Light pollution is a growing problem in reaction to excess light being given off by numerous signs, houses, and buildings. Polluting light is often wasted light involving unnecessary energy costs and carbon dioxide emissions. Light pollution is described as artificial light that is excessive or intrudes where it is not wanted. Well-designed lighting sends light only where it is needed without scattering it elsewhere. Poorly designed lighting can also compromise safety. For example, glare creates safety issues around buildings by causing very sharp shadows, temporarily blinding passersby making them vulnerable to would-be assailants.

6.4 Strategies for Energy Efficient Lighting

The challenge in lighting design is to provide sufficient light where it is required at the times when it is required, without providing excess light. If this is done using the most appropriate light sources and fittings, and combined with an effective control system, then substantial energy savings can be achieved. The key strategies to achieving this are as follows: Define light requirements. Use daylight as much as possible. Select efficient sources and fittings. Effective design of lighting layout. Effective control systems.

6.5 International Professional organizations

The International Commission on Illumination (CIE) is an international authority and standard defining organization on color and lighting. Publishing widely used standard metrics such as various CIE color spaces and the color rendering index.

The Illuminating Engineering Society of North America (IESNA), in conjunction with organizations like ANSI and ASHRAE, publishes guidelines, standards, and handbooks that allow categorization of the illumination needs of different built environments. Manufacturers of lighting equipment publish photometric data for their products, which defines the distribution of light released by a specific luminaire. This data is typically expressed in standardized form defined by the IESNA.



The International Association of Lighting Designers (IALD) is an organization which focuses on the advancement of lighting design education and the recognition of independent professional lighting designers. Those fully independent designers who meet the requirements for professional membership in the association typically append the abbreviation IALD to their name.

The Professional Lighting Designers Association (PLDA), formerly known as ELDA is an organisation focusing on the promotion of the profession of Architectural Lighting Design. They publish a monthly newsletter and organise different events throughout the world.

The National Council on Qualifications for the Lighting Professions (NCQLP) offers the Lighting Certification Examination which tests rudimentary lighting design principles. Individuals who pass this exam become ‘Lighting Certified’ and may append the abbreviation LC to their name. This certification process is one of three national (U.S.) examinations (the others are CLEP and CLMC) in the lighting industry and is open not only to designers, but to lighting equipment manufacturers, electric utility employees, etc.

The Professional Lighting And Sound Association (PLASA) is a UK-based trade organisation representing the 500+ individual and corporate members drawn from the technical services sector. Its members include manufacturers and distributors of stage and entertainment lighting, sound, rigging and similar products and services, and affiliated professionals in the area. They lobby for and represent the interests of the industry at various levels, interacting with government and regulating bodies and presenting the case for the entertainment industry. Example subjects of this representation include the ongoing review of radio frequencies (which may or may not affect the radio bands in which wireless microphones and other devices use) and engaging with the issues surrounding the introduction of the RoHS (Restriction of Hazardous Substances Directive) regulations.

List of References


List of References

Ref. No. Reference

1 Pohl W. & Zimmermann A., 6 November 2003 ,” SynthLight Handbook

Chapter 3 : Artificial lighting “ 2 Revision 1- September 2007, “ Section 9 Lighting – Artificial And Daylight “,

Energy Efficiency Building Design Guidelines for Botswana

================

Bibliography


Select Bibliography Books

• Brandi U. & Geissmar C., 2001, “ Lightbook : The Practice of Lighting Design “, Birkhauser – Publishers for Architecture, Basel, Switzerland

• Coles J. & House N., 2007, “The Fundamental of Interior Architecture “, AVA Publishing SA, Switzerland

• “Interior World : Volume – 12, Commercial Spaces II “, Archiworld Co. Ltd, Seoul,

Korea Websites

• Online available at, http://en.wikipedia.org/wiki/Lighting#cite_note-24, accessed on date 29 March 2012

• Online available at, http://www.popmatters.com/pm/review/132084-brilliant-the-evolution-of-artificial-light-by-jane-brox, accessed on date 29 March 2012

• Online available at, http://www.except.nl/consult/artificial-lighting-guide/index.htm#1, accessed on date 29 March 2012

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http://www.popmatters.com/pm/review/132084-brilliant-the-evolution-of-artificial-light-by-jane-brox�

http://www.popmatters.com/pm/review/132084-brilliant-the-evolution-of-artificial-light-by-jane-brox�

http://www.except.nl/consult/artificial-lighting-guide/index.htm#1�

http://www.except.nl/consult/artificial-lighting-guide/index.htm#1�

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