Small halogen spot lamps are normally used to give more focused beam or accent lighting. They are broadly used as a more energy-efficient alternative to incandescent bulbs in retail establishments and home lighting applications. Through a chemical reaction with the halogens, the tungsten filaments of halogen lamps are regenerated, and work at higher temperatures, their filaments are close to the surface of the lamps and the surface area is relatively small. Consequently lots of heat dissipated around the ambient lamp. Additionally, the lamp, especially the filament should not be exposed to serious vibration to prevent the lamp from failing prematurely.
For example, the power dissipation of the most commonly used par20, MR16, GU10 halogen lamps ranges from 20W to 50W, and their lumen output ranges from 160 lm to 700 lm. That equals to an efficacy of about 16 lm / W, or a luminous efficiency of 16%. The lifespan of a typical halogen lamp is limited to about 2000-3000 hours, probably equal to 3 to 4 months of use in a retail store.
So still consider halogen lamp as spotlights? Let's look at some data of LED spot lamp.
Spotlight bulbs are often placed as spot or accent lighting in the hard-to-reach smaller area, which people do not want to replace too often. LED lamp lasts many times longer than the conventional halogen lamp. Each lamp is made up of a cluster of small light emitting diodes, and is able to produce brilliant, bright, crisp, clear light can be a valuable retrofit of its halogen counterpart.
What's more, LED lamp needs very small proportion of electricity to give off a high level of lumen output, in other words, they get higher efficacy.As a matter of fact, MR16, GU10 and PAR LED Lamps, use much less power to emit the equal amount of light than halogen lamps. Today's LED technologies are able to give up to 110 lm / W, with three one watt power diode of this, the total light output would be nearly 300 lumens. Furthermore, the lamp has focused 15 °, 30 °, 45 ° beam angle to produce significant amount of usable light without much waste light as halogen lamp does. Thus, the service area need light would be stronger than or at least same as its halogen counterpart. Good news is that the LED technology is continuously improving from year to year rapidly, higher efficacy diode chips will be appeared in the market in the future.
LED spotlight bulbs do not rely on heated filaments or gas materials to give off light, they do not incorporate the use of mercury like fluorescent lamp. This means that LED lamps can be used close to delicate items such as jewelry, valuable merchandises in the retail store display case or shelf, expensive ornaments and photos in the house, without heat damage over time, or causing fading. Further more, LED lamp is best choice as environmentally friendly light. It create much smaller amount of CO2 emission than incandescent, halogen and fluorescent lamps. As LED technology matures, the lamp can also be made with dimmable function to meet the increasing demand by the end users.