Types of lamps

The lighting design process in its most basic form entails identifying a task and then providing a light source that will provide proper quantity and quality of light for the task. The fixture protects the light source, connects it to the power source and distributes its light. 

 

The light source is the actual light-producing component of the lighting system. It may operate simply as a lamp (incandescent/halogen) or as a lamp powered by a ballast (fluorescent and high-intensity discharge [HID]).

I-Incandescent Lamps:

Incandescent light sources are the cheapest light sources.

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·         Do not require a ballast

·          It is based on the fact that current is passed through a filament, which heats until it glows

·         Less efficacious light source

·         Shorter service life than other light sources in most cases

·         Filament is sensitive to vibrations   

·         Bulb can get very hot during operation

·         Must be properly shielded because incandescent lamps can produce direct glare as a point source

·         Require proper line voltage as line voltage variations can severely affect light output and service life

An example of incandescent lamps is given in figure 4.1

Efficiency of incandescent is 14 lumen/watt.                                

ii-Fluorescent Lamps:

These lamps rely on the gaseous discharge method.

·         Require a ballast

·         Low surface brightness compared to point sources 

·         More efficacious compared to incandescent

·         Ambient temperatures and convection currents can affect light output and life

·         Options for starting methods and lamp current loadings

·         Requires compatibility with ballast

·         Low temperatures can affect starting unless"cold weather" ballast is specified.  

An example of fluorescent lamps is given in figure 4.2

Efficiency of fluorescent lamps is 46 lumen/wat

iii- Compact Fluorescent Lamps (CFL):

·         It is a new and advanced lighting technology

·         More efficient than incandescent lamps

·         CFL use 70 - 75% less energy than their incandescent equivalents. When replacing a 100 watt incandescent lamp a 28 watt CFL is used.

·         CFL last approximately 10,000 hours, which is 10 to 13 times the life of an incandescent lamp (expected life approximately 750 hours).

·         Compact fluorescents are most cost-effective when used at least 2-3 hours per day.

·         Although CFL may appear different than the common incandescent, they fit most standard fixtures found in homes today. The screw-in base is the same on both lamps.

·         The typical incandescent lamp wastes 90% of the energy it uses, producing heat rather than light.

·         CFL will provide the same amount of light (or lumens) at a fraction of the electricity used.