Lighting assignment
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CHAPTER7LECTURE.pptx
LIGHT & LIGHTING SYSTEMS
General Considerations for Lighting Solutions
What tasks will be performed in the space and for how long?
Who are the occupants including age, disability, skin tone, etc.?
What is the extent of natural (daylight) available?
How big is the volume of the space?
What finishes and textures exist, e.g. glossy or matte?
General Considerations for Lighting Solutions (cont.)
What is the desired mood?
Is a high color rendering index (CRI) a key consideration?
How critical are energy-conservation issues?
What is the budget for initial lighting system and for ongoing maintenance?
Are there special codes relating to the lighting system and installation?
Light and Lighting Systems
Two basic categories of lighting:
Natural
Electric
They are used to provide three basic purposes:
Ambient (general)
Task/Local lighting
Accent lighting
These may also be referred to as Lighting Layers. Remember lighting creates ambiance or mood, it can have theatrical effects and it can also enhance well being. We must consider both the quality and quantity of light in a space and how to use it effectively.
Light “bulbs” are referred to as Lamps
Electric Light
Incandescent Lighting - This is the type of electric light is produced by the application of electric energy to a thin wire filament until it reaches the point of INCANESCENCE, which is the temperature that causes the filament to glow. Where natural daylight appears white under perfect conditions, the incandescent light is warmer and looks more yellow and is described as cozy. It generates more heat and is less energy efficient.
It was the 1st type of electric light and it was invented by Thomas A. Edison in 1879
It creates heat and consumes more energy than other types of light
Typical residential lamp – the A Lamp
Electric Light
Various halogen lamps are a form of incandescent lighting; also called tungsten-halogen or quartz-halogen
The halogen lamps render color better (have a high CRI) and are brighter than regular incandescent lamps.
CRI – Color Rendering Index
There are many types of incandescent lamps, the standard A, halogen and reflector which come in lots of shapes, sizes and wattages. A WATT is symbolized by the letter W and it’s the unit of measurement of the power consumed by the bulb/lamp
HALOGEN – is a subcategory of the incandescent bulb that was introduced in 1959. It is more accurately called TUNGSTEN – HALOGEN OR QUARTZ-HALOGEN, DEPENDING ON ITS CASING
The advantages are they render color better and are brighter than regular incandescent lamps. More hues are perceived in their true state as if under white light.
Another advantage is that it burns at a continuous rate or brightness where the standard bulbs fade out during their lifetime.
Compared with a standard lamp the halogen also has a high rate of EFFIACY – WHICH IS THE CRITERION THAT WE USE TO EVALUATE THE AMOUNT OF BRIGHTNESS A LAMP SOUCE PROVIDES IN COMPARISON TO THE ENREGY USED. So the Halogen releases more light to the amount of energy input than a A lamp.
Electric Light
A PAR (parabolic aluminized reflector) lamp
Various MR (mirror reflector halogen) lamps - High CRI
REFLECTOR LAMP
A REFLECTOR is a surface of mirrored glass or polished metal shaped to project the beam from a light source in a particular direction. Like spotlights.
They come in various BEAM SPREADS (is the distribution of light and its determined by the shape and faceting of the reflective surface.)and are really good for accent lighting.
FLOURESCENT LIGHTING
It was first introduced for use at the 1939 Worlds Fair in NYC. In this type of lighting a glass tubes in different lengths and widths is filled with a low-pressure mercury vapor producing an invisible ultraviolet radiation that activates white phosphorous crystals in the lamp. The phosphorus glows or fluoresces converting the ultraviolet energy into visible light energy. The light diffuses and unlike incandescent lighting is casts few shadows so its good for general lighting and can be used as task lighting as well.
Electric Light - Fluorescent lighting
Electric Light - Various fluorescent lights including CFL (compact fluorescent lamps)
NEON LIGHTING
Electric Light
Neon lighting is colored light produced as a result of different gases and vapors.
Neon lighting is used more in commercial applications and isn’t really used in residential applications. Its used to provide high visual impact in signs and billboards. They can be installed in small or inaccessible places because the tubes are easily bent when made and they last a long time.
Neon lighting creates an exciting environment in a Beijing market
Electric Light - Various HID (high-intensity discharge) lamps
ELECTRIC LIGHT
HID OR High Intensity Discharge lamps were developed in the early 1930’s. There are 3 basic categories of this bulb *Mercury vapor
*High pressure sodium
*Metal halide.
The differences in these and the way in which the colors are depicted.
They are used when the lighting needs to remain on for long periods of time and where maintenance would be inconvenient like in streetlamps and parking lots. Airport runways and stadiums.
Electric Light - Complex hospitality LED (light-emitting diode) project
LED LIGHTING
LED – Light emitting diodes developed in the 1960’s. They contain very thin sheets of carbon-based compounds that illuminate when their electrodes are stimulate by an electrical charge. They are low maintenance and there is no damaging heat emissions or ultraviolet emissions.
Since their introduction they have come a long way. The technology has improved them so that they can be used indoors and not just as exterior lighting or in digital displays. They can be digitally controlled also provide flexibility in color and brightness and have special effects.
They are more expensive to purchase initially but they last so long it makes up for the cost.
Electric Light
Use of light as a design tool
Colored LED Cove lighting – A term used to describe distributing light across a ceiling
Architectural focal points are highlighted
Lighting Terms
Kelvin – Used to measure the temperature of light, is it warm or cool?
Foot-Candles are the level of light delivered to a surface.
Lumen is the international unit used to measure quantity of light.
CRI – Color Rendering Index is used to determine how well actual color is “rendered” by the light.
LRV – Light Reflectance Value is a measurement that determines how well a surface, like a painted wall, will reflect the light. The lighter and the smoother the surface the higher the LRV.
KELVIN
KELVIN –Color temperature is measured in degrees of KELVIN- named after the scientist who discovered the phenomenon of how warm or cool the light is or the ratio of red to blue in appearance.
The LOWER KELVIN values are warmer in temperatures and higher values are cooler.
KELVIN
CRI
Unlike color temperature, CRI is a measurement of how a well a light bulb will show an item’s true color.
See page 153 in textbook.
Glare & Veiling Reflection
Currently, office work is mostly done on computers. This is why extra care should be taken about the interactions between the light sources and the computer screens, in an early stage of design. Inadequate lighting creates glare on computer screens and forces people to be inventive with shading devices. A light source, either primary or secondary (window, luminaire, light wall), can cause a veiling reflection on a computer screen.
Light’s Relationship to Other Factors: Form
Beam spreads of directional lighting give form to light in a space
A beam spread angle greater than 25 degrees is called a Flood
Throw Distance is a term used to describe how far and at what intensity the illumination will go
Light’s Relationship to Other Factors: Surface
Lighting techniques:
Wall Washing (Left); Wall Grazing (Center) Scalloping (Right) provide special effects when calculated precisely.
Unidirectional or Omni-directional lighting is called Diffuse Lighting and we can use Back Lighting when we want to create a silhouette for drama.
Wall Washing vs. Wall Grazing
Wall Washing is when light is uniformly spread out over a wall from top to bottom. Evenly illuminating the entire wall hides imperfections and eliminates shadows.
Wall Washing vs. Wall Grazing
Wall grazing, on the other hand, is intended for the opposite effect: to accentuate textured vertical surfaces by exaggerating shadows.
Unlike wall washing, which highlights features on the wall, wall grazing turns the wall itself into the focal point of the room. Wall washing lights walls at a wider angle to create a clear, bright wall and highlight anything showcased on it, whereas wall grazing skims the surface of the wall at a narrow angle to accentuate the beauty of rough or interesting textures through shadows. Both techniques call attention to walls and are a unique way of manipulating how certain spaces or surfaces appear to the human eye.
Scalloping
Placing recessed down lighting adjacent to a wall can create interesting shadow effects, especially when placed along corridors or a visually interesting side of a room.
While these shadows are not desirable in general lighting, when carefully controlled and intentionally placed, they can have a very dramatic effect on a space.
This accent lighting technique is referred to as light scallops due to the rounded shape that is created from the cone of light coming from the fixture as it hits the vertical wall surface.
Back Lighting
Create a silhouette for dramatic effect
Lighting Fixtures: Luminaires
Pendant Lighting
Torchiere Lighting
Lighting Plan and Schedule / Lighting plan and lighting symbols
Terms To Remember
Neon
LRV
Kelvin
Lumin
Adaption
Efficacy
Accomodation
Veiling Reflection
