21 SIGNIFICANCE OF ENVIRONMENTAL FACTORS IN AN INTERIOR: SOURCES OF LIGHT AND REFLECTANCE FACTOR

S. Visalakshi Rajeswari

Introduction

Technological advances may be innumerable, but for any building or structure, the fundamental purpose or the primary function stays more or less unchanged. It has to protect the inmates from the external environmental influences on the one hand and from natural calamities on the other. In recent years, gratifying both the functions satisfactorily along with an eye for aesthetics is receiving priority. A project affording a ‘designed space’ not only as a status symbol but also a space which promises the needed comfort and convenience to perform the functions allocated to it is in the premium. Hence, the perception by the inmates in such interiors gains significance. There are many factors in the environment the designer has to consider in the designing process to gratify the required needs. Considered in those terms, the geographical location of the space and the type of architectural features desired emerge as major deciding factors. An understanding of the factors therefore becomes essential. Perhaps, light as an environmental factor warrants special address as it is received in two forms – natural and artificial.

Objectives

This module entails the following major objectives

·         Delineate environmental factors and their influence on space designing

·         Project practical measures to have a control of the factors to promise conducive environments for living

·         Know about light, the supportive medium, and its manipulation

Environmental psychology is a well emerged branch of study that considers the interplay of human relations and behaviors within the context of the built and natural environments – the interplay of the micro, meso and macro environments. This branch of study relates fairly well to the aspects considered in space designing. The physical environment existing outside the house obviously affects the emotions and behavior of the people who occupy spaces, especially the rooms in a house. For instance, even when staying indoors a cloudy day can cause discomfort and mental disturbances for a person. Similarly, a noisy event, for example a political meeting being conducted in the neighborhood can be disturbing for an elderly/ patient and a student preparing for exams. Though they happen in the external environment, their impact can be great on the inmates. These are pointers addressing the significance to be accorded to segregate external environment intrusions while designing interiors. It may demonstrate how internal structures are to be built /designed so that external influences have the least influence on the qualities of the interior and the residing inmates.

Coming to the point under consideration, it can be said that those factors which can pose as a challenge in the natural world can be successfully manipulated and utilized in other forms and used in interiors. With scientific research revealing all the ways our environments affect the mind, these factors all the more become very crucial in designing space. The field of environmental psychology calls for designers to look through a different lens, and strategically examine the inner lives of the people who use their buildings. The goals lie in integrating environmental factors such as HVAC, illumination, color, art, and ergonomics into the unconscious mind, so that one’s perception is positive; which in turn shall motivate one to be more effective wherever they are and in whatever they do. Environmental psychology as a field of study exhibits an overlapping similarity with many other disciplines like planning spaces for living, Ergonomics and Human Factors, Lighting, Sound and acoustics, Interior design etc.

The interior design approach has been defined as the process of creative problem solving: a process of creative, constructive behavior. It is a systematic process of conscious thought that integrates academic knowledge with imagination. The design process can be viewed as a sequence of steps or stages. When something is designed the designer will have to think about a number of things which will usually have a large impact on the design and how it eventually turns out. One needs to visualize the outcome before embarking on the design process. The factors which need to be considered by the designer during the design process are: intended function, aesthetics, user needs, concepts on sustainability (economic, social and environmental) laws pertaining to buildings (residences, industries, offices and other work places) ergonomics in designs, safety and security, factors contributing to maintenance of sound health, availability of tools, materials expertise and existing trends.

There are several factors in the external environment, which by default have either an entry or have an influence in an interior space. They need to be understood, their influence on inmates analyzed and measures to tackle them practiced. They exert an influence on the behavioral aspects of the people using the spaces. Evidently, the ultimate aim of providing a comfort zone for the inmates becomes not as a question of choice. Hence, consideration of these factors in space designing gains significance. Few such environmental factors are:

Ø  Incident daylight (natural)

Ø   External temperature

Ø   Humidity (nearness to seashore)

Ø   Annual / seasonal rainfall

Ø   Direction of wind

Ø   Type of land/ terrain

Ø   Topography

All these factors showcase a concrete impact on the residents staying within a built environment. To curtail the impact a basic practice of control over the indoor environmental quality would prove highly beneficial. Indoor environmental quality includes statements for nine specific characteristics. It includes four characteristics of indoor air quality and five characteristics of human comfort which need to be addressed in all kinds of space designing.

Pointers of satisfaction for appreciable Indoor air quality

Ø  Draft the plan meeting the basic requirements for indoor air quality

Ø   Restricted exposure of the inmates to environmental tobacco smoke

Ø   Controlled IAQ issues resulting from construction or renovation process

Ø   Selection of low-emitting materials and furnishings

Human comfort

•  Facilitate high level individual occupant control of HVAC and lighting systems
• Ensure appropriate thermal conditions
• Create interface between indoor spaces and outdoor environments through daylight adequacy and beautiful views
• Monitored optimal acoustic conditions
• Devise energy – efficient lighting mechanisms and optimum control

According to the Samkhya School, light is one of the five fundamental “subtle” elements (tanmatra) out of which emerge the gross elements. The Vaisheshika School gives an atomic theory of the physical world on the non-atomic ground of ether, space and time. The basic atoms are those of earth (prthivi), water (pani), fire (Agni), and air (vayu). Light rays are taken to be a stream of high velocity of tejas (fire) atoms. The particles of light can exhibit different characteristics depending on the speed and the arrangements of the tejas atoms. The Vishnu Purana refers to sunlight as “the seven rays of the sun”. Light and lighting are thus elements considered indispensable in a person’s everyday life.

Among all elements lighting is the most important one. It is a vital element of design. It affects not only one’s perception but also one’s response to the environment. Good lighting makes a house warm and friendly, lively or restful and is also essential for efficient vision. An ideal lighting can be obtained by having enough knowledge on their importance, requirement, types and lighting required for specific areas. Selection of the right kind of lighting in appropriate places adding glamour and charm too to everyday living receives special mention. Lighting is an environment factor that affects every human being. Any surface that is struck by light rays reflects some of that light. So it has to be handled with caution.

v  Importance of Lighting

Lighting in the interior of a house should be given due consideration because of the following reasons.

• Seeing things properly and clearly requires ample lighting. It further enhances visibility
• An adequately illuminated house always looks bright
• Emphasizing an area or an object in the interior and exterior of the house comes easily with proper lighting
• Work productivity and outcome can be improved with adequate lighting facilities
• Prevention of accidents both in interiors and exteriors warrant good lighting
• Lighting choices reflect the inmate’s taste, character and individuality
• Colour scheme in interiors about which much thought has been focused receives attention only in properly placed lighting
• Sunlight can kill germs which are present in the surroundings.
• Natural light keeps one healthy, cheerful and also enable procurement of Vitamin D

Lighting or illumination is the deliberate use of light to achieve a practical or aesthetic effect. It includes the use of both artificial light sources like lamps and light fixtures, as well as natural illumination by capturing daylight. Day lighting (using windows, skylights, or light shelves) is sometimes used as the main source of light during daytime in buildings. This can save energy in place of using artificial lighting, which represents a major component of energy consumption in buildings. Proper lighting can enhance task performance, improve the appearance of an area, or have positive psychological effects on occupants.

Indoor lighting is usually accomplished using light fixtures which are a key part of interior design. It can also be an intrinsic component of landscape projects. Permitting maximum diffused light into the interiors can create dramatic effects. But, utmost care should be taken to avoid glare and shadow and over brightness in interiors as they are highly harmful to the human eye Several measurement methods have been developed to control glare resulting from indoor lighting design. Unified Glare Rating (UGR), Visual Comfort Probability, and Daylight Glare Index are some of the most well-known methods of measurement. Further, four main factors also are said to influence the degree of discomfort glare; the luminance of the glare source, the solid angle of the glare source, the background luminance, and the position of the glare source in the field of view. All these must be taken into account while providing lighting. Source, type and purpose of light and the reflectance factor of materials used and surfaces present decide the achievement of satisfaction the user desires.

1.    Sources of light

The major source of light is the Sun of course. Beyond that, artificial light in the home is primarily produced from an electric current flowing into an incandescent bulb or fluorescent tube.

• Natural lighting

Sunlight, of course is the single natural light. It gives very bright light, kills germs and purifies the air. It can be warm, yet provide light which will bring out the true colours in objects. Hence, their significance in interiors

• Artificial lighting

The two commonly used sources of artificial lighting in interiors, based on lighting elements used are of two types: incandescent bulb and the fluorescent tube.

Incandescent bulb: These typically have a tungsten filament that is heated by electricity to the temperature at which it glows. It affords a concentrated source of light and can be directed easily to a point or area. The bulbs light instantly an area and are easy to maintain, but they produce glare and have a lower output and shorter life which make them more costly to operate than fluorescent lights. Because their fixtures are simpler and bulbs of different wattages can be used in the same socket, it is used more often in homes. There are three general categories of incandescent bulbs: general purpose, reflector bulbs used for accent lighting and decorative bulbs.

Incandescent light is produced by heating a tungsten filament sealed within a glass bulb, until it glows. This kind of lights generate heat, so it is important to allow for air circulation between the bulbs and ceilings or walls, or it will cause the bulb to burn out quickly and often results in scorched ceilings above the fixtures. They are available in many different shapes, sizes and amounts of light produced. Because of their warm glow, they display a tendency to alter colour schemes and modify the reflectance factor of materials and furnishings used. They in fact influence the internal environmental conditions as they give a warm glow and cause eye discomfort due to glare and shadow effects leading to problems in visibility.

Fluorescent tube: These tubes offer a luminescent or cold source of light. A glass tube with an inside coating of fluorescent powder is filled with vapourized mercury and argon. The ends are then sealed with cathodes. When electric current is passed, it activates the fluorescent powder to glow. When the gases are activated, invisible ultraviolet rays cause the fluorescent coating to produce visible light. Although fluorescent tubes come only in straight or circular shapes and curved tubular forms, they have considerable diversity in colour. They are also much less energy consuming than incandescent bulbs. They diffuse more evenly (uniformly), and reduce glare and shadows. It can provide both cool and warm atmosphere. Because the installation requires more than the simple switch and socket of the incandescent bulbs, its initial cost is higher. But the tubes last longer, are cooler, require fewer fixtures and use less electricity than incandescent. Their greater efficiency and economy make them much more practical for everyday use.

A third type of lighting using CFLs and LEDs have stolen the hearts of consumers now which are practically more efficient, brighter and durable and above all energy efficient. They advocate for the concept of environmental sustainability too.

The types of artificial light chosen for use in interiors can be considered to fall under four utility based aspects

1)      Choice based on purpose and effect

2)      Choice based on type of lighting element used

3)      Choice based on reflection

4)      Choice based on lighting fixtures

Type of artificial lighting (choice based classification)

Choice based on purpose and effect: These offer three types of lighting. They are:

a. Ambient or general lighting: It illuminates a room uniformly, like how the Sun illuminates the earth. It enables people to see every corner of a room in a safe reassuring way and brings to equal attention the design and colour of the whole space. It minimizes bulkiness of furniture, the darkness of shadows and often harsh contrast of local lighting. It is rarely bright enough for close work and it can be harsh and monotonous. So it is always combined with local lighting. It can produce glare and shadow.

b. Task / local lighting: It indicates direct and functional illumination needed in specific places for specific activities, such as reading, cooking, sewing, eating etc., provided by this lighting. This light source can be high or low, but shielded (covered). Local lighting also creates pools of light that attract attention and draw people toward a circle of activity and warmth. It can be used to help direct traffic, set a mood, locate up large rooms into islands or make a small room appear to have several, distinct areas thus visually enlarging its space. It assures focused illumination. Usually the source of lighting is a portable lamp with some type of shade to concentrate light in a certain direction.

c. Accent or decorative lighting: Typical source of decorative lighting include candles, crystal chandeliers, fixtures with many small lamps, pin spot or tiny Christmas light. The special contribution made by accent lighting can be experienced immediately when one enters a room filled with sparkling light. It stimulates, helps accentuate focal point and provide the personal touch that highlights a room. This kind of lighting enriches one’s environment by establishing a pleasing ambience. It may be illumination of an art object, the receptive flow in an entry way, or coloured globes infusing a space with tinted light. It may be a combination of general lighting and task lighting.

Reflectance factor

This is another aspect about which designers have to practice caution as the lighting provided ipso facto can create fantastic lighting effects or cause concern for reflectance. It is calculated as the ratio of the reflected to the incident flux. Stated in simple terms it is the reflection of a fraction of the radiant energy reflected from the surface. Interior designers, architects, consultants for colour and paints in interiors, environmentalists and even medical personnel building a hospital show interest in deciding this factor before choosing a colour, paint, glass or metal accessories and flooring tiles. This is applicable to all kinds of buildings, especially residences. So, a small amiss can change the ambience in its totality. The aspect of reflectance is the factor that can decide if one’s home is welcoming, peaceful, calm, cool and rejuvenating for the user. Contrarily it can be jarring or re-nerving or very harmful to normal sight. To create proper ambience, materials and accessories in the interior are chosen based on their Light Reflectance Value (LRV), which is an indication of the visible and usable light that gets reflected from a given surface when it is lighted by a known source. They are generally given in the labels of many products. Designers planning the lighting component in an interior estimate the number and type of light sources and fixtures based on these values. It enables them to provide appropriate lighting effects desired by the clients to satisfy exclusive needs. They are also highly essential in places where children, elderly and physically challenged people reside, where this aspect comes in hand to caution them about important aspects like wall – to – floor junctions, floor levels, ramps, door corners, handles for grabbing and the like in a contrast colour.

LRV is a value depicting the proportion of light reflected back from the surface. So, more polished a surface higher the reflection; more opaque, higher the absorption and more specular, higher the transmission. It all depends upon ultimately the material of the surface where the light falls. Room surfaces and luminaire reflectors also showcase typical reflectance levels.

Metals display maximum reflectance factor as high as a range extending from 50 – 92% (low polished nickel to highly polished silver), 20 – 70 % by finishing materials (Granite to Marble) and 10 – 85 % by various paints (Brick colour to white). Similarly, concrete, ply wood cabinets, wood/ timber used for furniture and doors – all reflect the light falling on them to a certain extent. If not treated properly, this character of light as a supportive medium may jeopardize the entire decorative system in the interior.

Summary and conclusion

In summary, it can be said that the environmental factors may appear very docile; but their impacts on mankind especially in indoor situations can prove harmful. Relegating due respect to each and every environmental factor will render a very healthy place to live in. Inspecting personal surroundings and rectifying defects if any would come in handy in the long run to lay an environmentally appreciable environment and good lighting in particular.

Web links

• https://en.wikipedia.org/wiki/Light_reflectance_value
• www.lrc.rpi.edu/education/learning/terminology/reflectance.asp