Lighting

Artificial Light Previously the 2 main types of artificial lighting was incandescent and fluorescent. New technology is replacing the old with other types of light sources

Light produced when an electric current passes through a fine tungsten filament inside a bulb Incandescent Light Another form of Incandescent lighting. Halogen gas combines with tungsten molecules to activate a filament inside a quartz enclosure Tungsten-Halogen Produced in a glass tube by releasing electricity through a mercury vapor to make invisible ultraviolet rays Fluorescent Light Types of Artificial Lighting

In CFLs, an electric current runs through a tube containing argon gas and a small amount of mercury vapor Compact Fluorescent Lamps Heatless light produced by passing an electric current through a cable containing very fine strands of glass Fiber Optics Composed of crystals on silicon chips and light is produced when a low electric current passes through them Light-Emitting Diodes (LED) Types of Artificial Lighting

Incandescent Light

 The electricity heats the filament until it glows giving off light  Incandescent light bulbs range from 15 to 250 watts for the home.  The higher wattage gives more light  A lumen is a measurement of the amount of light a bulb produces  A higher lumen means the bulb emits more light  Incandescent bulbs produce very little light for the energy used  Not a very efficient source of light

Incandescent Light  Bulbs for the home use have a frost finish to  Reduce glare  Make shadows appear softer  Use clear bulbs only in fixtures that hid the bulbs  A three-way bulb can produce different amounts of light in a single bulb

The Energy Independence and Security Act  Established energy efficiency standards for many types of light bulbs  This includes the proposed phase-out of incandescent and other inefficient bulbs

Tungsten- Halogen (Quartz) Light

 Produces a whiter type of light  Bulbs last up to three times longer than regular incandescent bulbs  Tungsten is a metal compound that is released from the filament into the bulb  There is a small amount of halogen in the bulb that when it reacts to the tungsten, it creates light

Fluorescent Light

 A coating of fluorescent material on the inside of the glass tube converts these invisible ultraviolet rays into visible light  Produces about four times as much light as an incandescent bulb of the same wattage  Tubes are more expensive but last longer and are less expensive to use  Color varies by changing the fluorescent material coating in the tube  Cool-white intensifies blues and greens  Warm-white intensifies yellows, reds, and oranges  Often used in kitchens, bathrooms, and workshops

Compact Fluorescent Light

 Replacing old incandescent bulbs  Uses a regular light bulb socket and comes in many sizes and shapes  Some CFLs have a cork-screw shape and newer models look like standard incandescent bulbs  Use about 75% less energy and operates for nearly 9,000 hours  Broken CFLs can emit a small amount of dangerous mercury, so dispose properly

Fiber Optics

 Permit transmissions over longer distances and high bandwidths  Dramatic Effect in interior spaces

Light-Emitting Diodes (LED)

 Composed of crystals on silicon chips the size of a grain of salt  Produce light when a low electric current passes through them  Can last 10,000 hours or more  More expensive but,  Lasts longer  Energy efficient  More durable  Gives off less heat

Properties of Light

 Can use to achieve several effects in a home  Objects and surfaces absorb or reflect light  Light can shine directly on a certain spot or lighten a whole room

Reflected Light  Light, color, and texture are closely related  Without light, there is no color  Colors reflect and absorb various amounts of light  Rough textures look dark because tiny shadows form where the light does not reach  Reflected light is light that bounces off surfaces  Light comes from the surface and the source  Surfaces that reflect light include  Light colors, background treatments, smooth/shiny surfaces  Avoid lighting placement that creates glare

Absorbed Light  Drawn in by a surface  Rough textures and dark colors absorb most available light rays  If light is absorbed, it cannot be reflected  A room with many dark surfaces may require additional light for certain activities

Diffused Light  Light that scatters over a large area  No glare and creates a soft appearance  Devices that diffuse light, or diffusers, spread light evenly  A lamp shad covering a light fixture serves as a diffuser

Light Temperature  Color temperature is the color of light as rated in kelvin (K)  A temperature scale that impacts how items appear in light  Light from these sources is divided into the following general tones:  Orange (incandescent) *K  White (halogen) *K  Blue (florescent) 3000*K for warm, 4000* for cool  Keep in mind how the light affects the surfaces when selecting lights

Color Rendering Index (CRI)  Indicates how well light from a source brings out the true color  The CRI scale is from with 100 equaling the color rendering of daylight  The closer the CRI of a light source is to 100, the more accurately the light reproduces color

Functions of Lighting

 Illuminates the environment so that people can comfortably see when performing certain tasks  Especially those that pose a safety hazard  Lighting also brings attention to  Beautiful objects  Attractive architectural features

Lighting for Visual Comfort  Two types of lighting create visual comfort  General (Ambient)  Task  The type and amount of light needed varies from room to room

Ambient Lighting  General lighting provides uniform light throughout a room  Lighting that shines directly toward an object is direct lighting and  Provides the most possible light to a specific area  Creates a sharp contrast between light and dark areas  Should be used with other room lighting  Indirect lighting is directed toward a surface, such as a ceiling or wall that reflects light into a room  Indirect Lighting  May provide soft light for a large area  Is not enough light for detailed work

Task Lighting  Used in areas where specific activities require more light  The right amount of light helps prevent eyestrain  The finer the detail or the faster the action taking place, the more light is needed  Task lighting can serve as general lighting for another part of a room  Combine general and task light to give adequate light without sharp contrast  Use higher levels of task lighting to assure good vision when performing tasks  Writing  Carving Wood  Sewing  Reading

Measuring Light  Wattage is the amount of electricity a light bulb uses  A lumen is a measurement of the amount of light a bulb produces  One lumen is the amount of light produced by a source equaling the intensity of one standard candle  Foot-candle is a measurement of how much light reaches an object or surface  One-foot candle is the amount of light a candle gives to an object one foot away  One foot-candle equals one lumen per square foot  You can measure the amount of light reaching a surface with a light meter

Lighting for Safety  Prevent accidents and fires  Light your way from room to room  Switch lights on and off from each doorway  Turn on stairway lights when using stairs  Light entrances  Control garage and carport lighting form inside or outside the home  Control outside lighting form inside the home  Wiring must meet safety standards  The National Electrical Code is a standard with which all wiring should comply  Underwriters Laboratories (UL) is a safety-testing organization  Always read and follow the instructions the use and care of the lights

Lighting for Beauty  Some lighting is decorative, which adds beauty to a space  Soft light can create a quiet, restful mood  Sharp light can highlight the focal point in a room  Accent lighting is a form of lighting that serves as a highlight  Use a decorative lighting outside the home  Yard lights next to the street  Lights near entrances  Lighting patios for night use

Structural and Nonstructural Lighting The two ways to deliver light

Structural Lighting  Permanently built into a home  Keep structural light fixtures in harmony with other aspects of the room’s design  Consider the following points about structural lighting  Diffused light gives more visual comfort  Fixtures that can change position to allow for usage in more than one way  Provide different light levels allow for more flexibility in the home

Structural Lighting  Types of structural lighting fixtures include:  Valance lighting  Bracket lighting  Cornice lighting  Cove lighting  Recessed down  Soffit lighting  Wall washers  Strip lighting  Track lighting

Nonstructural Lighting  Nonstructural lighting is lighting that is not a structural part of the house  Move, change, and replace these lights more easily than any other lighting  Lamps are the most common type of nonstructural lighting  When choosing lamps, consider  Sturdy or heavy base, prevents tipping  Prevents glare  Harmonizing colors and textures  Light-colored, translucent lampshades