lighting design considerations

LIGHTING DESIGN CONSIDERATIONS

GUIDED BY

AR. P. PRAKASHAR. RAVI JAIN

PRESENTATION BY

SANDAL USMANIMOMIN MOHAMMAD ZAKI

2ND YEAR – M. ARCH BUILDING SERVICES

FACULTY OF ARCHITECTURE & EKISTICS - JAMIA MILLIA ISLAMIA

Lighting Design

Lighting Design

“Design” is the science and art of making things useful to humankind; and lighting design is the application of lighting—including daylight when it is specifically used as a source of lighting—to human spaces. Like architecture, engineering and other design professions, lighting design relies on a combination of specific scientific principles, established standards and conventions, and a number of aesthetic, cultural and human factors applied in an artful manner.

FORMAT OF PRESENTATION

Design Considerations

Lighting QualityLight Distribution, including:• Task and ambient lighting• Day lighting integration• Light pollution and light trespassSpace and Workplace Considerations, including:• Flexibility• Appearance of the space and luminaires• Color appearance• Luminance of room surfaces• Direct glare• Reflective glareLighting on People and Objects, including:• Modeling faces and objects• Surface characteristics• Points of interest

Lighting Quantity

Task Illuminance

Implementation

Economic / Cost ConsiderationEnergy / Sustainability

Design Consideration – 1. Lighting Quantity

Lighting Quantity

For general lighting purposes, the recommended practice is to design for a level of illumination on theworking plane on the basis of the recommended levelsfor visual tasks given in CODES (NBC) by a method called ‘Lumen method’. In order to make the necessary detailed calculations concerning the type and quantity of lighting equipment necessary, advance information on the surface reflectance of walls, ceilings and floors is required.

Task Illuminance

Task Illuminance describes the amount of light falling on a surface. It has two components.1. Amount of Light –

(based on usage or multiple usage of a space)After detailed study and research CODES – provides values

&

2.If the surface is horizontal - horizontal illuminanceif the surface is vertical - vertical illuminanceSome tasks though are at an angle, such as reading a book in a hospital bed.

Design Consideration – 2. Lighting Quality

Lighting Quality

Lighting profoundly affects many human reactions to the environment. These human reactions range from the obvious, such as the dramatic beauty of an illuminated landmark or the emotional response of a candlelight dinner, to subtle impacts on worker productivity in offices or sales in retail stores.

Light Distribution, including:• Task and ambient lighting• Day lighting integration• Light pollution and light trespass

Space and Workplace Considerations, including:• Flexibility• Appearance of the space and luminaires• Color appearance• Luminance of room surfaces• Direct glare• Reflective glare

Lighting on People and Objects, including:• Modeling faces and objects• Surface characteristics• Points of interest• Sparkle

Design Consideration – 2. Lighting Quality / Distribution

Lighting Quality• Task and ambient lighting

Task lighting systems independent from the space’s general lighting systems (serving specific task) are found in building types for instance, the display lighting in retail stores is a form of task lighting. Similarly, task lights are used in industrial manufacturing and assembly, health care, residential lighting, and many other interior lighting applications.Options include – indirect luminaires mounted atop cobinetry or workstations– Suspended luminaires– Recessed luminaires

Ambient Lighting:

Task lights can’t light the balance of the room, and thus some other type of lighting system is needed to produce the ambient illumination in the room.


Lighting Quality

Task – Ambient Lighting produce energy

savings in three ways:

•Locating the light source close to the task

most efficiently produces the illumination

levels needed for the task.

•Task illumination levels don’t have to be

maintained uniformly thorugh out the space,

so ambient levels can be lower.

•Some occupants won’t use their task lights,

and empty offices or workstations with absent

occupants don’t have to be fully illuminated


Lighting Quality

Day lighting Integration

Practice of using windows, skylights and other forms of fenestration to bring light into the interiors of buildings using various means.

Incorporating day lighting in the lighting design can be done by:•Proper control of the fenestration luminance•Daylight sensing and compensation control systems which allow adjustments to electric electrical lighting system•Glare controls should also be incorporated in the design•New techniques for “piping” light into interior spaces can allow sunlight and daylight to furnish a higher percentage of illumination requirements and more uniform distribution


Lighting QualityLight pollution & light trespass

In outdoor lighting, electric light may illuminate adjacent properties which become offensive if unwanted is known as light trespass.Electric lights emitting light upward o reflecting light upward cause a condition called light pollution which causes moisture and particles in the air to glow at night.

Several steps to minimize light pollution & light trespassUse night lighting only when and where necessaryUse the minimum amount of light needed rather than the maximumUse sources with cutoff optics that restrict light to the intend area of illuminationUse more sources, each of lower wattage, to improve uniformity in the intended illumination area and minimize trespass into adjacent areas.

Design Consideration – 2. Lighting Quality / Space & Workplace

Lighting Quality

Space and Workplace Considerations, including:• Flexibility• Appearance of the space and luminaires• Color appearance• Luminance of room surfaces• Direct glare• Reflective glare


Lighting Quality

• Flexibility

Advance lighting designs should be flexible enough to ensure that:Lights operate where needed, and are off where not needed, as people move around within a space and use rooms in different ways.Spaces used for “hoteling” – the occasional or transient use of a workspace – remain dark unless needed.The lighting space system can be rapidly reconfigured to match a changed floor plan or accommodate a different space use, and still operate at maximum energy efficiency.The lighting system permits multiple uses and on-demand flexibility in multiple-use spaces such as conference rooms and modern A/V classrooms.

Design Consideration – 2. Lighting Quality/ Space & Workplace

Lighting Quality

Appearance & Space of luminaires

Luminaire efficiency and the ability to use efficacious sources have become increasingly important criteria for selecting luminaires.

Designer should find lighting systems that embody the project’s style or aesthetic but to do so using high-efficacy sources and efficient principles.For instance, choose luminaire that “hide” light source but avoid such as crystal chandeliers that require lamps with bare incandescent filaments.

Design Consideration – 2. Lighting Quality/ Space & Workplace

Lighting Quality

The appearance of color

both in terms of

color rendition (CRI-Colour Rendering Index)

Correlated colour Temperature (CCT)

are important in the overall feeling of the space, and in some instances can have a dramatic effect on visual tasks.


Lighting QualityColor Rendering Index (CRI) describes how a light source makes the color of an object appear to human eyes and how well subtle variations in color shades are revealed. The CRI is a scale from 0 to 100 percent indicating how accurate a "given" light source is at rendering color when compared to a "reference" light source. The higher the CRI, the better the color rendering ability. Halogen is considered the “reference” light source and has a CRI of 100.CRI of 100 in an LED source has not yet been developed. CRI in the 90’s is possible but very expensive.Fluorescent lamp sources are considered very poor in CRI running in the low 70’s. A CRI index >80 is considered very good.


Lighting QualityCorrelated Clolour Temperature

For good visual comfort, light needs to have the right color and quality.Light can feel cool or warm. This is quantified by the "color temperature" and measured in degrees Kelvin. The higher the color temperature, the bluer the light is. This may seem counter-intuitive, as we think of blue as a "cooler" color than red, but it comes from the physics of black body radiation. People generally prefer bright light to be bluer, like daylight, while they prefer dim light to be yellow, like candlelight. The color temperatures of daylight and various common light sources are below.


Lighting Quality

Luminance of room surfaces – Periodic trends in interior design introduce dark paints and finishes. These trends contribute to difficulty in producing energy-effective design by increasing lighting requirements to raise surface luminance into the comfortable range.Lighting designer should:Encourage the use of high diffuse reflectivity (light colored) surfaces and minimize the use of dark surfaces.Use computer modeling to ensure that the average room surface luminance is at least 10% of the task background.With indirect lighting systems, use computer calculations to check for uniformity and try to maintain 10:1 luminance ratio or better.


Lighting Quality

Direct Glare. Caused by a view of the light source, often with high contrast to the surroundings.Glare is associated not just with lamps, but also with daylight, especially when one is exposed to low angle, direct sunlight.Be concerned– more about the glare caused by lamps, lenses and other overly birght sources of manmade lights– less about glare of sunlight and small point sources – most concerned about sources of glares in relation to the stationary tasks when building occupants cannot easily relocate themselves or their tasks


Lighting QualityReflective GlareHave long been associated with gloss-coated paper, pencil paperwork and computer CRT (cathode ray tube) screen.Indirect lighting, by creating a diffuse and uniform illumination has been advocated as solution.Can create specular reflections that can cause glare reducing comfort or disabling the worker’s vision in particular areas.Reflective glare - when system has been optimized to reduce glare – then consider:modifying the task to eliminate remaining glare problem suchas use of flat screen CRT or active matrix.Use of ink rather than pencilUse of matte-coated or uncoated paper rather than gloss coating paper.Changing finishes of polished floors or shiny conference room tables.


Lighting Quality

Lighting on People and Objects, including:• Modeling faces and objects• Surface characteristics• Points of interest


Lighting QualityModeling faces and objects

In human vision, shadows and highlights enhance the perception of three dimensions. Both are the products of directional light sources. The sun and the moon produce well-defined shadows, and are considered dramatic and attractive light sources.Diffuse light, like the light from a cloudy sky, produces an even light that is relatively shadow-free. Once considered desirable, it is now realized that shadow-free light can fail to render changes in surfaces making a space or task less visible. To model a surface for better recognition of its shape and features, in general some percentage of directional light is considered important.

Consider using a blend of direct and indirect lighting in most designs to provide a combination of comfort and modeling.To achieve a minimum modeling, a directional light for an object or area of interest should be at least 20-25% of the total illumination.


Lighting Quality

Surface Characteristics

Lighting techniques that reveal architectural nuance like texture enhance visual perception have become more commonly requested by building owners and architects


Lighting QualityPoint of Interest

In retail and museum lighting, designers use highlights of up to 10 times the ambient light level to draw attention to key display.Recognize that it’s wasteful to create lighting than is needed.Carefully select highlights, and use a minimum effective highlight level.Creating highlights in contrast to lower ambient illumination levelsCreating highlights with efficient sources as close to the object or surface as possible.Small points of light from fiber optic sources or LEDs may offer efficient ways to create highlights or attract attention where specifically desired.

Design Consideration – 3. Implementation

Implementation

Implementation

Economic / Cost Consideration

Energy / Sustainablity

Design Consideration – 3.Implementation

ImplementationEconomics / Cost Consideration

All of the costs and benefits associated with a lighting project should be considered in a careful economic evaluation of a lighting system. These include:

• Installation costs (Including equipment cost)• Design and management costs• Energy costs• Maintenance costs

Advantages Of “Lighting Design Service” In Terms Of Cost Saving

Equipment Cost ControlIdentifying Lowest-Cost Unit Pricing

Operations Cost ControlAvoiding Over-LightingImproving Reflectance and Integrating Daylight

People Costs (increased sale /productivity)Aesthetic Costs


ImplementationLighting Economics – An Example


Implementation

Simple PaybackThe period of time in years required for the savings in operating or maintenance cost to equal the additional initial investment required for the lighting system.

Lighting Economics – An Example


Implementation

Incorporate proper lighting controlsInfrared sensorsMotion sensors�Automatic timers�Dimmers�

Energy Efficiency

Use of Daylight

Replacement with energy �efficient lampsCFLs and LEDs

Energy-efficient lighting design focuses on ways to improve both the quality and efficiency of lighting.•Match the amount and quality of light to the performed function.•Install task lights where needed and reduce ambient light elsewhere.•Use only energy-efficient lighting components, controls and systems. These include Fluorescent and LED lighting options.•Maximize the use of daylighting. Daylighting is the use of windows and skylights to bring natural light into your home.

Energy Efficiency

End . . . . .

Referenceshttp://www.energywise.govt.nz/your-home/lightinghttp://www.algonline.org/index.php?lighting-quality

ADVANCED LIGHTING GUIDELINES – 2011 edition by algonline

lighting design considerations

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