Photosynthesis in Homo-sapiens

When you type light or illumination in Google, the first thing you get is its scientific definition and measurement units. Wikipedia defines light as ‘light is electromagnetic radiation within a certain portion of the electromagnetic spectrum.’ That means nothing to, say a chartered accountant, a chemistry student or a fashion designer. But that does not mean they all don’t use light. In fact, light is required in each and every activity invented by the mankind; even in music one needs to see where ones fingers are moving on a guitar or flute, one needs to know that they are not putting salt in tea instead of sugar.

The importance of light being established, one often wonders what our ancestors did without electricity. Well, they just went fine with their daily work. The sun rose in the east, set in the west, providing light throughout the day. The plants grew, the herbivorous ate the plants, the carnivorous ate the herbivorous and man, well he ate everything he could get his hands on. Essentially what is important here is that the sun was a constant source of heat and light. The abundantly available light was used by plants to photosynthesize their own food which was consumed by the rest of the food chain. It may not be far-fetched here to say the even human beings use light to complete biological cycles.

Consider no artificial lights, no technology, and now imagine a primitive human life. What did man have for a reference of time? The sun. Suppose you are taking a nap, you wake up having no idea of what time it is. Since you live within walls you will have to check your watch for time. But the caveman did not. He only had the reference of the sun. Now you will say that if the cardinal directions are unknown one cannot justify if it is morning or evening without the passing of time. But here lies the theory. As the Sun crosses the sky, it appears to be red, orange, yellow or white depending on its position. The changing color of the Sun over the course of the day is mainly a result of scattering of light. The mornings are orange, while the evenings are purple. And this is what our body has been accustomed to for millions of years. This is known as the circadian rhythm. Ever wondered why you feel happier in the mornings while lesser in the evenings? Why do you feel sleepy earlier in the winter? What is the whole concept of jet-lag? It is all a part of the circadian rhythm of your body.

The general population today spends at least 8-9 hours a day in their workplace. Natural lighting is the least important there. The color of artificial light is constant and doesn’t resemble daylight at any point of time. This essentially destroys the circadian rhythm. Studies have shown that being exposed to the same light, without any change, increases fatigue and decreases productivity. In a third world country like India, the daytime indoor lighting is dependent on electricity, which is neither cheap nor consistent. Blackouts are being a common phenomenon in the rural and semi-urban areas. This fluctuation of illumination triggers stress hormones and often affect the productivity as well as the comfort feeling of the occupant. Whereas complete dependency on daylight at least keeps you feeling comfortable throughout the day.

If you just consider the relation of light with architecture, light has more of an effect of a person’s experience within a space than any other architectural design element, and so it is considered to be one of the most important components of architecture. The perception of space is directly connected to the way light integrates with it. What we see, what we experience and how we interpret the elements is affected by how light interacts with us and with the environment. Due to the light, it is possible to perceive different atmospheres in the same physical environment. The garden which looks like a family space during the day looks like a romantic spot during the evening.

Can we have the same environment for our habitable spaces? Incorporating daylight into our buildings will certainly improve its mood quality, the productivity of employees and students, creating a more pleasant environment. Of course people will debate the negative effects of incorporating daylight, especially in a hot country like India. There is the glare, the heat coming with light and the uncertainty of available daylight. That is what is keeping people from actually using daylight. But that is what an architect and a lighting designer is for. Just by providing large windows for inviting daylight, will result in users closing the blinds because of the glare and then switching on the artificial light.

Just like every other living creature under the sun, we too gain our energy from Him(sun). Not exactly the physical energy which helps you work, but a psychological force which drives your mood, either to work or relax. And that is how, just like the photosynthesis of plants, we synthesize our intellectual energy from the changing daylight. And the lack of which in today’s work and residential spaces is one of the reasons of increasing tensions and fatigues.

Today multiple products and features are available to work with, if one just decides welcome daylight into habitable spaces. It is possible to create a healthy and happy environment for everyone, if we just try to tap this amazing source of energy.

Daylight Autonomy and India

The Egyptians used daylight controls to temper the heat of their extreme climate, introducing lattice and screens with different size openings to allow for daylight penetration into space. In Rome, buildings were designed around courtyards surrounded by living space to maximize available daylight. European Renaissance masters revered light as both a practical and aesthetic design tool. The baroque style used indirect light to create mystery and intrigue in buildings, but as electric lighting sources and technologies improved; daylight took a back seat in lighting design.

Today, encouraged by updated building codes, new energy regulations, and a renewed emphasis on sustainability, architects, building owners, and lighting designers are once again embracing daylight as a practical, aesthetic, and symbolic element of good building design. This is known as designing for daylight.

Just using daylight for habitable spaces and affirming the building to be green is not enough in today’s competitive world. That’s where the concept of usable daylight comes in picture. Hence the concept of daylight autonomy was evolved. Spatial Daylight Autonomy and Annual Sunlight Exposure allow designers to quantify and compare the success of daylit spaces. (Kevin Van Den Wymelenberg, 2016) It basically acts as a judge on the qualitative daylight performance of the building.

This concept has been devised by IESNA and applied for the design of many buildings in the USA, where the amount of available daylight is low compared to the tropical climates. However, this concept needs to be emphasized in tropical climates since the available exterior illumination is high. The actual usable daylight times in India are pretty short since most of the time the daylight is too harsh. Therefore, there is a need for correlation of daylight autonomy with Indian climatic context.

Daylighting is an important aspect of achieving energy efficiency in built form. The significant contradiction arises in buildings in the hot climate regions when relating window sizes and shadings to achieve both reduced energy consumption (requiring minimum opening ratios and more shading) and sufficient daylighting (requiring maximum opening ratios and less shading). (Mohamed Amer Hegazy, 2013) Natural lighting has two noticeable effects, Light and Heat. In hot climates, large windows can provide more daylight but higher cooling loads, while small windows can decrease energy consumption but do not offer sufficient daylight. Hence, hot climate is considered one of the most challenging climates when it comes to daylighting (A., 2012)

What is Daylight?

The entire natural light available from the sun and reflecting sky. It is an important feature to be considered for designing an energy efficient building, as it reduces the load on electric lighting during daylit hours.

What does Autonomy mean?

It means independence or freedom.

Daylight autonomy essentially means the autonomy in natural light, meaning that space does not require artificial light to perform activities, which happens to be the core of sustainable lighting design. It means to maximize the amount of useful daylight, thereby minimizing or eliminating the need for supplemental electric light.

What is useful daylight, and how is it defined?

Useful daylight illuminance (UDI) is a modification of daylight autonomy which places illuminance between 100 – 2000 lux. The range 0-100 lux is termed as under-illuminated and insufficient for functioning, whereas above 2000 lux is termed as over illuminated causing glare. There is little research to support the selection of 2,000 lux as an absolute upper threshold. Basically, UDI guarantees visual comfort.

Useful daylight is independent of daylight factor. Daylight factor calculates the percentage of interior illumination with respect to exterior illumination. Exterior illumination differs with latitude and sky conditions. Hence DF cannot be termed as an ultimate measure of interior illumination.

Calculation

Daylight autonomy is calculated as the percentage of time when the architectural project is autonomous with daylighting in functional hours. Illumination on each point throughout the daylit hours of the year will be measured. The percentage of time at which the daylight on that particular point falls between 100-2000 lux (UDI) will be calculated. This is presented as the daylight autonomy if the point. For a successful design, it should at least be 50%. It is a major innovation since it considers geographic location-specific weather information on an annual basis.

In case the basic requirement for the function is 300 lux, the user is free to set the threshold above which Daylight Autonomy is calculated. For the graphs above, we selected a Daylight Autonomy threshold of 300 lux (DA300). The graphical percent values represent the percentage of the floor area that exceeds 300 lux for at least 50% of the time.

Figure 1 calculation of daylight autonomy

Importance

All the criteria in ECBC, IGBC, LEED, GRIHA, etc define the lower threshold of illumination through daylight. Most of the activities have minimum lux levels defined, like 300 lux for office working, 50 lux for circulation, etc. However, knowing the dynamic nature of daylight, buildings and daylight apertures designed for overcast sky conditions, will provide illumination much more than required. Lux levels as high as 3000-4000 lux will be achieved. This can easily cause glare for the occupants and hamper functioning. In such conditions, it is observed that the occupant will close the daylight aperture and will rely on the more adjustable artificial lighting. This will defy the whole purpose of sustainable lighting. Hence there is a need to define the upper threshold of illuminance through daylighting.

Daylight autonomy defines the lower as well as the upper level of illumination. This range is termed as usable daylight illumination. Furthermore, it defines the percentage of time in the whole year where a particular point will receive daylight within the usable range. This can define the annual daylight performance of the building. Since most of the buildings when designed for daylight are designed only for overcast sky conditions, the annual performance is ignored. This results in actually higher usage of artificial illumination in highly daylight hours. Thus daylight autonomy can form a better measuring unit for the annual daylight performance of the building.

Available exterior illumination in the tropical climate of India

India is a tropical climate lying between latitudes 8 degrees to 32 degrees north. With respect to solar position and available exterior illumination, this is a wide range. The available exterior illuminations for different latitude are given in the following table.

(Littlefield, 2012)

The skies are mostly clear except for the months of July and August, resulting in abundant daylight available from 8 am to 4 pm, the primary daylit hours.

Correlation between daylight autonomy and Indian climate

Daylight is the visible part of solar radiation and daylight at these latitudes can also mean thermal gain. In addition, bright sky reflected light from the ground, and direct solar radiation can be causes of glare. To avoid overheating, daylight is normally blocked by shading devices or highly reflective glazing. To manage glare, most traditional diffuser materials and glare management systems reduce the usable output lumens as direct light is blocked and spreading increased. As a result, interior spaces can be dark and many buildings depend entirely on artificial lighting for illumination, even when external illuminance levels are very high.

The significance of daylight autonomy in higher exterior illuminance of India

Daylight autonomy gives a measure of total illumination on the work plane available throughout the year in daylit hours. It considers the lower as well as upper threshold. The lower threshold can be modified according to the function and activity requirements. Daylight is dynamic, thus there is no one common solution for all scenarios. It is more critical in the tropical climate where the sky is predominantly intermediate; with inconsistent clouds formations which will influence the presence of direct sunlight and daylight availability. Daylight autonomy is a dynamic measure of daylight illumination. Therefore it is proposed that instead of any static measures like daylight factor or illumination in overcast conditions, daylight autonomy or continuous daylight autonomy with the help of useful daylight illumination will form a better evaluation method in Indian climate.

Softwares used to calculate daylight autonomy

Daylight modelling is an effective way of predicting the daylight performance of the building. Ecotect provides an excellent tool for the same. The modelling can be done in Ecotect while lighting analysis can be carried out in radiance or daysim. Radiance can provide a time by time calculation of daylight, whereas daysim provides an annual matrix in the form of daylight autonomy. The upper and lower levels of illumination can be set in daysim for usable daylight.

Artificial Lighting Design… necessity, luxury or fantasy?

Our world is divided into many parts. However every human being is living in two worlds throughout his life; inner world and outer world. Let us consider inner world as spiritual world and outer world as materialistic world because most of our internal processes of human beings are not in our control. When we say spiritual world, we will always consider India at the core of it. The Sanskrit name for India is ‘Bharatha’, which originally meant Agni or fire

Source: http://www.bharathgyan.com

We can call fire as form of light; hence light has very deep meaning in our spiritual world. In short we can say light means knowledge or wisdom. Even when we considered someone who has grown spiritually or in wisdom, we call them ‘enlightened’, which essentially means that the light of knowledge has shone upon them. We can find such examples even in our ancient spiritual texts. An example of which is shown below.

ॐ असतो मा सद्गमय ।
तमसो मा ज्योतिर्गमय ।
मृत्योर्मा अमृतं गमय ।
ॐ शान्तिः शान्तिः शान्तिः ॥
Om Asato Maa Sad-Gamaya |
Tamaso Maa Jyotir-Gamaya |
Mrtyor-Maa Amrtam Gamaya |
Om Shaantih Shaantih Shaantih ||

Meaning:
Om, (O Lord) Keep me not in the Unreality (of the bondage of the Phenomenal World), but lead me towards the Reality (of the Eternal Self),
(O Lord) Keep me not in the Darkness (of Ignorance), but lead me towards the Light (of Spiritual Knowledge),
(O Lord) Keep me not in the (Fear of) Death (due to the bondage of the Mortal World), but lead me towards the Immortality(gained by the Knowledge of the Immortal Self beyond Death),
Om, (May there be) Peace, Peace, Peace (at the the three levels – Adidaivika, Adibhautika and Adhyatmika).

Even the 7 spiritual chakras are signified by 7 colors of the sunlight, each chakra denoting different form of enlightenment.

We find light is very important source in our inner world but we don’t realize that because we are not enlightened since birth. There are certain processes to get enlightened and our spiritual scriptures can guide us for the same.

Now when it comes to outer / materialistic world, are we considering light as one of the primary source of living? The five senses are the bridge to our inner world, and sight (vision) is one of the important senses. We see outer world through our eyes and our brain interprets it with the help of nervous system.

Someone says, “Your outer world is reflection of your inner world” but we will think here in reverse way from lighting point of view. Our inner thoughts and moods are a reflection of what we see. This can be comprehended with the help of few examples.

Most of us love to see starry night sky, ocean, camp fire, sunrise and sunset but have you wondered why we love it?

A simple yet intriguing answer could be whenever we see starry night sky, we feel like we are connected to the universe and yet so miniscule and insignificant.

Whenever we visit sea shore we feel positive vibrations inside which increases our confidence.

Whenever we sit in front of camp fire we feel warm and secured in the range of light.

Whenever we see sunrise we feel hopes are alive and whenever we see sunset we get relaxed. Now these all are feeling and emotions evoked inside after seeing outside things but most of the working population doesn’t even see sun during our week days.

We read about the importance of daylight in our earlier articles, and also we understood how light affects our circadian rhythm. Basically daylight provides us the various color shades of white light and intensity of light throughout the day and human brains have engraved to this cycle from thousand years.

Here we are trying to understand what artificial lighting design is and why is it necessary. If certain views and qualities of light have certain effect on our emotions, can we replicate it in artificial lighting design, to create comfort and save energy where required. Generally we are spending our day in office and night at home and unfortunately in both places we are using white light (6500K).

This is interrupting our circadian system and causing side effects on our health. We have a disturbed sleep pattern, early diseases and easy fatigue. Have you wondered why the branded retail showrooms look more appealing than local retail stores?

We see a certain difference in lighting and color there, than what we see in normal stores.

vs

vs

We find gold jewellary more beautiful in stores than when we bring it home. What could be causing this? It most certainly is the color and intensity of light in that store, or more precisely the lighting design. You find yourself more attracted towards a cozier coffee shop, even if the coffee there tastes shit (considering its price). You certainly feel more comfortable in a 5 star hotel than a cheap motel. Certainly the other aspects of interior play a bigger role in it. But those won’t matter with a faulty lighting design.

A professional lighting designer knows what color temperatures, light intensities, beam angles to use for what kind of activity. He understands the psychology and physiology of the occupant and the lighting requirement. Basically he is the right person who thinks from multiple directions to bring ultimate solution. He provides the lighting solution keeping human being in center as well as enhances the architecture or interior design of the space. So, next time you visit a place and feel it to be just right, stop and analyze why, is it just the interiors or does lighting design playing the trick for you.

Co-authored by Amit Chavan, Lighting Ergonomics, Pune

Light pollution

We have wide dictionary of hyped up words today. Some of them include green revolution, non-conventional energy resources and pollution control. When we say pollution, there are many things that come to our mind; water, air, sound and land being our primary concern. All these pollutions we are familiar with, but do we know the definition of pollution? Pollution is described as introduction of contaminants into the natural environment that causes adverse change. Here precisely the contaminants are termed as harmful to both human beings and the environment. But can it be possible that a contaminant may be beneficial to human but have an adverse effect on the rest of the environment? Or still further it is beneficial only to some humans, while proves as a nuisance for some.

Artificial lighting is the ultimate example of this type of pollution. It is termed as lighting pollution. Any amount of excess of light, where it is not required is termed as pollution. Then this light could also be a light coming from your house disturbing your neighbor’s sleep. It could be up-lighting on facades of buildings or flash lights shot into the sky disturbing the routine of nocturnal animals. It could even be excess of streetlights in less crowded areas hampering the view of star gazers and astronomers.

Imagine coming tired home, wanting a good night sleep on a weekday. But your neighbor is having a bright party, with flashlights shooting up your glass window, penetrating right through your curtains and onto your closed eyes. And now you can’t even sleep. He is not making noise, so you can’t even complain. Well, you can’t complain in India. But in most of the developed countries you can complain about this situation under light trespass. Any light entering your property, against your will, after sunset can be registered as an offence of light pollution.

This term was initially introduced by star gazers, since they couldn’t look onto any stars from their comfortable homes in the city. It was majorly for light going in the vertical direction up in the sky, which hampered the view of the celestial objects. For most of Earth’s history, our spectacular universe of stars and galaxies has been visible in the darkness of the night sky. From our earliest beginnings, the vast spectacle arrayed across the dark sky has inspired questions about our universe and our relation to it. The history of scientific discovery, art, literature, astronomy, navigation, exploration, philosophy, and even human curiosity itself would be diminished without our view of the stars. When we walk solely in moon light, our eye becomes accustomed to less amount of illuminance; as a result we can clearly see the dimly twinkling stars and lit planetary objects in the night sky. With excess amount of artificial light being present both in the surroundings and projected onto the night sky, the sky just becomes a dark mass, devoid of all celestial objects. Here there is no room for such curiosities about the vast expanse of the universe. Today, many star gazing groups have to travel to distant remote locations to get a clearer view of the night sky.

Not just humans, but animals are also affected by light pollution. Both bright days and dark nights are necessary to maintain healthy hormone production, cell function, and brain activity, as well as normal feeding, mating, and migratory behavior for many species, including humans. Basically, light pollution affects the circadian rhythm of diurnal animals. But the most affected are nocturnal animals like bats. Their eyesight is evolved to work best during dark hours. They hunt in the dark, roam in the dark and eat in the dark. They cannot perform their normal activities because of excess artificial light being present in their environment.

Lighting pollution can be classified into four different types.

• Urban Sky Glow—the brightening of the night sky over inhabited areas. Affecting the star gazers and nocturnal as well as diurnal animals.

• Light Trespass—light falling where it is not intended, wanted, or needed. Like on neighbor’s property while he is sleeping

• Glare—excessive brightness which causes visual discomfort. High levels of glare can decrease visibility. A car coming from opposite direction using a high beam light on a dark unlit road.

• Clutter—bright, confusing, and excessive groupings of light sources, commonly found in over-lit urban areas. The proliferation of clutter contributes to urban sky glow, trespass, and glare.

Indian green building council has set a credit aside for addressing the issue of lighting pollution. However neither IGBC nor ECBC (energy conservation building code) are mandatory as yet in India for any type of buildings. Today like addressing any other pollution and environmental problems, it becomes our moral responsibility as conscious co-inhabitants of planet earth, to look onto this problem with equal dedication. We owe it, not just to fellow humans but rest of the living world of this planet.

So how can we work towards reducing lighting pollution? There are few simple thumb rules. For façade lighting down-light your building instead of up-lighting, just for the need of aesthetics. When designing or choosing street lights, make sure that no more than 5 % of the illuminance goes above 90 degrees z axis, meaning there is a solid cap above the light bulb that prevents light from being emitted directly to the sky, to minimize sky pollution. Select exterior light fixtures with cutoff angles to prevent light from escaping above the horizontal plane (nadir), minimize up-lighting, and reduce high-angle brightness. Use compact fluorescent lamps (CFL) and LED bulbs that produce warm white lighting. Many LED lights emit a blue short wavelength light that scatters easily into the atmosphere, which causes eyestrain, impairs night vision and adds to light pollution. Turn off any unnecessary outdoor lights when you are home for the night or before going to bed to prevent wasteful dusk to dawn lighting. If you’re in doubt, turn them off by 11 PM. While you’re at it, make sure to turn off indoor light fixtures, like wall lights, when you’re not home or before bed to reduce energy consumption.

For a detailed comprehensive study you can always refer to http://www.delmarfans.com/educate/basics/lighting-pollution/#prevention website.

Color and Perception

Every human being has five senses, namely vision, hearing, touch, smell and taste. If we were to depend solely on touch, smell, sound or taste, the limits of our environment would be defined by the span of our arms or legs. We would not have a clear sense of direction only based on sound signals. We would lack the ability to differentiate colors, transparencies, and textures. Light and vision create an internal world of distances and depth, of colors and contrasts, of volumes and textures that the majority of us inhabit.

This light, not only gives us a clear idea of our surrounding, but also serves as a food for our physical and mental well being. In the first article the importance of the circadian rhythm was established, meaning the importance of the changing color and intensity of light. However even constant exposure of different kinds of light, natural or artificial, has certain effects on the human body. ”It seems clear that light is the most important environmental input, after food, in controlling bodily function,” reported Richard J. Wurtman, a nutritionist at the Massachusetts Institute of Technology.

Now to understand exactly what part of light affects us, we need to understand the construction of light. Considering that light is a wave form as established by Christiaan Huygens (other than as particles as said by Newton) we can define few parameters of light.

People experience light as having three features: color, brightness, and saturation. These three types of experiences come from three corresponding characteristics of light waves:

• The color or hue of light depends on its wavelength, the distance between the peaks of its waves.
• The brightness of light is related to intensity or the amount of light an object emits or reflects. Brightness depends on light wave amplitude, the height of light waves. Brightness is also somewhat influenced by wavelength. Yellow light tends to look brighter than reds or blues. This is an attribute of the human eye being most sensitive in this wavelength region.
• Saturation or colorfulness depends on light complexity, the range of wavelengths in light. The color of a single wavelength is pure spectral color. Such lights are called fully saturated. Outside a laboratory, light is rarely pure or of a single wavelength. Light is usually a mixture of several different wavelengths. The greater number of spectral colors in a light, the lower the saturation. Light of mixed wavelengths looks duller or paler than pure light.

Understanding that, we can further explore effects of different wavelengths or different colors on human body and mind. Many experiments have proven that light affects the mood of the person. Presently certain studies are also being conducted to understand the physical impacts of exposure to a certain kind of light. Yellow color stimulates happy thoughts as well as better digestion. Red color promotes more energy and vigor; however it often sometimes signifies danger. Blue on the other hand is often used to treat depression and hormonal imbalance.

natural light componants

The sunlight being made of all 7 colors (Violet, Indigo, Blue, Green, Yellow, Orange and red) provides us with all colors in varying quantities throughout the day. Presently available artificial lighting when giving out white colors gives a combination of 3 colors, Red, green and blue. Hence the color is different and so is the effect. Different colors in artificial lighting can be brought out by different permutation and combinations of RGB. Hence here, artificial light can very well be used for treatment of different physical and psychological disorders.

artificial light componants

There was this experiment in a school in California; when children under detention at the San Bernardino County Probation Department in California become violent, they are put in an 8-foot by 4-foot cell with one distinctive feature – it is bubble gum pink. The children tend to relax, stop yelling and banging and often fall asleep within 10 minutes.  This color is often called passive pink in color psychology.  Within the past decade, for instance, baths of blue light have replaced blood transfusions as the standard treatment for about 30,000 premature babies born each year with potentially fatal neonatal jaundice. In the United States, ultraviolet has become a standard treatment for psoriasis. And white fluorescent light, in conjunction with photosensitizing drugs, is widely used to help heal herpes sores

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calming pink room

However all of these are useless unless we can find an application of color theory in our day to day life and buildings. What we need to know that red color stimulates appetite; hence it can be very well used to adorn the walls of a restaurant. Blue-green color emphasizes freshness and can be used to light up the vegetables in a grocery shop. For that matter we can even see in the ‘Bhaji mandai’ in most parts of mumbai, where green vegetables are lit with green light, while tomatoes with red. Dull yellow or yellow orange shades make you relax and can be used in hospitality to make you feel comfortable. A brighter white light improves your concentration and should definitely be the lighting color of school and offices.

red interiors of restaurant

In branding and marketing, the psychology of colour is widely used as well. Many marketing experts see colour as an important aspect of selling since colour can be utilized to influence the perceptions and emotions of services and goods. Also, companies use colour when deciding on the logos of brands. Logos such as these seem to attract more buyers when the brand logo colour matches the personality of services and goods.

Even if we go to our aboriginal culture we see a heavy reference to colors when we talk about activating the ‘chakras’ in our body. Each chakra in your spinal column is believed to influence or even govern bodily functions near its region of the spine. Light flows through our eyes and triggers hormone production, which influences our entire complex biochemical system. This biochemical system then affects our being. And light does not travel alone. It is believed that each of the seven colors affects each of seven chakras.

colors and chakras

Stating this, we can definitely consider the light color theory as a guiding principle while designing our built environments with respect to the function and psychology of the inhabitants.

 

 

Renaissance in Lighting

When we talk about lighting or a lighting design today, the first thing that comes to mind is artificial lighting with all the flashy and colorful LEDs, Halogen lamps and Tubular lights. We talk about creating an ambiance for the night, when the light itself is controllable. No one wants to integrate a highly non-predictable source of lighting for glorifying your building, even if it is free of cost. When someone talks about using daylight as an element of aesthetics, it is called a radicle thinking. Even modern(since sustainability is the new trend) for that matter. However we fail to recognize that the thinking which we are calling unconventional is actually the most conventional. The first use of coal for thermal energy has been recorded in 1712 AD. While electricity was used for lighting not until later half of 18th century. Did people not build before that??

Almost every known historic civilization is known for its peculiar style of Architecture. Every culture had different values set for using daylight. Most of it depended on the climate and of course the availability of daylight. During this periods for some cultures daylight was the symbol of purity and knowledge. For some even the form of building was response to incorporating daylight into built spaces. Where the daylight was plenty and harsh, the size of the opening of the window was reduced while some diffusing elements like grills and lattice work was used. However where the climates were cloudy and the amount of daylight received was low the openings were large and barrier free. Even the placement of the openings depended on the type of illumination available.

Starting with oldest recorded culture(since the ancient Indian buildings are unavailable for study) the Egyptians who actually worshiped the Sun God, gained a harsh light through out the day, the size of their openings was small. Moreover there was a constant fear of sand storms. Hence the openings for lighting couldn’t be placed at human level. This gave rise to the concept of clearstory windows. As shown in the figure by Nyole Florence Chepchumba a part of the roof was raised and the sides of the raised part were used as openings for light. This way light never directly entered at eye level creating a glare.Some designs went even to create slit openings in the roof. As shown in the famed movie ‘The Mummy’ mirrors were used to redirect light from such slit openings in the rest of the building.

Ancient Greece suffered from lack of sunlight rather than its abundancy. Hence most of the activities were outdoors and building was just another sculpture to be viewed in daylight. However this period is known to illuminate the deity in the temple extravagantly. Openings were faced on the east and deity was placed on the west. This resulted in illuminating the deity with direct morning sun, glorifying its finer detail work.

When we talk of the great Roman empire the first great structure that comes to the mind is the Pantheon. Pantheon had a great corrugated dome with a circular opening at the apex. One can track the position of the sun depending on the beam of light coming from this rose window(a common name for circular windows in roman architecture). Not only that the diffused reflection from the roof teamed with the bright flooring creates an ethereal experience.

The early Christian Architecture used colored glass to incorporate daylight while giving it a distinct character. The color mosaics were generally religious depictions.

When we come to our culture, the only remaining ancient buildings are prominently the temples. Like every other culture we had a different ideology with respect to light and utilized it differently. We we look at out temples, we enter a bright semi open Mandapa, which transcends into a closed Antarala with windows and leads us finally into an almost dark Garbha Griha. This signifies a journey from light to dark. Where you leave all your worries and attachments of the world behind slowly and come in the presence of the divine. However in some temples including the Tulja Bhavani temple in Maharashtra and Sun Temple(Konark) in Orrisa the sun rays reach the idol, at a particular time on a particular day. It can not be a coincidence that those days are also auspicious in Hindu calendar.

However a study dedicated to Sun temple in Konark and other temples and churches dedicated to the ‘Lord of Light’ deserve a separate article in itself.

What we need to understand is that designing for daylight, not just functionally but aesthetically as well is not a new science. We need to study and revive those old techniques with respect to the climate of our design. Yes few modern architects like Le Corbusier and Tadao Ando have used daylight beautifully in there structures, but majority of buildings are lost to artificial illumination. Designing an artificial illumination for the night is not precisely condemnable, but at the same time we should consider the aesthetic use of this beautiful and ever changing source of light.

 

 

Lighting the day with numbers – Quantitative benefits of day-lighting

• In the last article the qualitative property of sunlight was discussed and emphasized; its importance for well being and productivity of human mind. It is a no brainer that soon questions will be raised against its quantitative importance, its financial benefits and environmental gains. No one disagrees with the fact that using daylight will obviously save electricity and hence the expenditure, reducing the production cost or cost of living (depending on the typology of the building). But how much will it save? What are the benefits, financially for us and environmentally for mother earth? Of course “how and where” to use daylight shall be discussed in the coming articles, but first we need to establish the quantitative importance of using daylight.

According to world energy statistics, today approximately 11% of the energy in the form of electricity is used for lighting in an Air conditioned residential building and 18% in commercial buildings; while, it is 22% in non Air conditioned buildings, as is the case of most of the lower urbane and all rural buildings in India.

Every office you see, every small home you see, every large beautiful mansion you see, the occupant either has insufficient daylight entering through small, wrongly placed windows, or they want to highlight the interior features with the controllable artificial light. We often see architects trying to ape the west by creating high rise buildings with a glass skin. In a country like India with abundant daylight, this often results in excessive sunlight. As a result the occupants close the windows with blinds and switch on the very controllable artificial light. It comes at its own cost. Can an architect find a way to distribute daylight evenly in the interiors? Can a designer find ways to use daylight for illumination during day, which will highlight all the important design features? Answers to all these questions are yes, but I hope discuss on it in articles to come.

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Let us try to simplify the calculation of using artificial light. Different activities require different amount of light. A jeweler fitting a diamond in the ring will require a lot more illumination than a worker in a factory doing the same work again and again, for which he is habituated to. One requires less amount of light when they are relaxing at home than when they want to read. An incandescent lamp, our common bulb, while looks beautifully cozy, is the least efficient. We have forever known to buy a lamp based on its wattage. We used to buy a zero bulb as the night lamp, a 40 watts bulb for our bathrooms and 60 watts for our living spaces. Here we are not defining the amount of light we get from it, but electric consumption of the lamp.

An incandescent lamp uses only 10% of its energy to produce light, rest 90% is converted to heat, further escalating the global warming crisis.  For the same required amount of light, a Tube-light or a CFL will consume only half the electric energy. An LED will use only 20% of it. But still all of them will consume energy and cost you money. None of them come as free as the sunlight.

Now if we consider the environmental impact of using artificial lighting, even with the availability of sunlight. Each unit of energy we use requires actually 2 units energy to be produced since there is a heavy loss in transmission, even if you may not bear the cost financially. Today India is highly dependent on fossil fuel. Not only fossil fuel is on its verge of extinction but burning it also creates carbon dioxide. CO2 is responsible for the present global warming scenario.

None of this is leading us to sustainable development. According to Brundland, “Sustainable development is development that which meets the needs of the present without compromising the ability of future generations to meet their own needs.” It essentially urges us to use our resources today such that our future generation won’t curse us for leaving nothing for them. By not using the most amazing source of light, the Sun correctly, we are defying the very essence of sustainability. Till a better everlasting source of energy (electricity) is available for us, we should try to save the present source as much as we can, and use the abundant sunlight correctly for illumination. Judicious and appropriate use of sunlight can form a basic guideline for future architects and designers, for functional as well as aesthetic purpose.