Because incandescent and halogen bulbs create light through heat, about 90% of the energy they emit is in the form of heat (also called infrared radiation). To reduce the heat emitted by regular incandescent and halogen light bulbs, use a lower watt bulb (like 60 watts instead of 100).
Fluorescent light bulbs use an entirely different method to create light. Both compact fluorescent bulbs and fluorescent tubes contain a gas that, when excited by electricity, hits a coating inside the fluorescent bulb and emits light. (This makes them far more energy efficient than regular incandescent bulbs.) The fluorescent bulbs used in your home emit only around 30% of their energy in heat, making them far cooler.
Halogen is a type of incandescent lamp. It has a tungsten filament just like a regular incandescent that you may use in your home, however the bulb is filled with halogen gas. When an incandescent lamp (one which produces light by heating a tungsten filament) operates, tungsten from the filament is evaporated into the gas of the bulb and deposited on the glass wall. The bulb "burns out" when enough tungsten has evaporated from the filament so that electricity can no longer be conducted across it. The halogen gas in a halogen lamp carries the evaporated tungsten particles back to the filament and re-deposits them. This gives the lamp a longer life than regular A-line incandescent lamps and provides for a cleaner bulb wall for light to shine through.
3. Why do halogen bulbs last longer than incandescent?
The life of incandescent and halogen light bulbs, referred to as tungsten filament lamps, is limited by the state of the filament. The filament is the wire inside the bulb that produces light when heated. The light bulb will not work if the filament is broken which may occur as a result of the application of force, such as dropping the bulb, or by lack of tungsten in a particular area over the filament. During the operation of tungsten filament light bulbs, tungsten from the filament evaporates into the gas inside the light bulb. When the tungsten comes in contact with a cool surface it will condense. Often, with incandescent products, the tungsten condenses on the bulb wall. Because the tungsten is redeposited on the wall instead of the filament, the filament grows thin over time. Eventually, there will be a point on the filament with so little tungsten that the filament will break and the light bulb will stop working.
Halogen light bulbs have a special gas inside their bulb containing halogens. The halogen gas facilitates the "halogen regenerative cycle" which means that the halogens carry the evaporated tungsten back to the filament instead of allowing it to deposit on the bulb wall. By placing the tungsten back on the filament instead of the wall, it delays the filament breaking due to lack of tungsten. Although the halogen cycle significantly increases the life of the light bulb, it cannot last forever because the halogen gasses cannot place the tungsten on a specific spot on the filament to avoid any place having too little tungsten and breaking.
The term "dichroic" applies to GE MR16 lamps specifically, not in general to low-voltage halogen lighting. For the GE MR16 lamp, dichroic describes the type of coating on the reflectors. These coatings can also be described as "multi-layer interference films". They are made up of dozens of layers of thin materials that have the unusual property of selectively reflecting or transmitting certain wavelengths of visible light, IR, and UV. Such dichroic coatings have been used since the 1960s to reduce the heat in the beam of certain reflector lamps (GE calls them "Cool-Beam" lamps). MR16 ConstantColor™ coatings are more sophisticated since they not only reduce the heat in the projected beam (up to 66%), but also absorb UV and control the color and amount of the light from both the front and back of the lamp - keeping it constant over the life of the lamp. The coatings are also very durable and will not flake off or deteriorate as the lamp burns.
MR16 lamps without cover glass should only be used in a closed fixture (fixture that keeps all parts of bulb enclosed) since the filament tube of all MR16 lamps is pressurized. In the unlikely event that the filament tube breaks, the closed fixture keeps glass particles from leaving the fixture. MR16 lamps with a built-on cover glass can be operated in an open fixture since the cover glass will contain any broken pieces of the filament tube.
6. Why does my floodlight need to be protected from water splash by an enclosed fixture or overhang?
In general, the PAR family of lamps, which typically includes spotlights and floodlights, is preferred for outdoor applications over lamps made with thinner glass and glass that is not heat resistant. However, PAR lamps are susceptible to breakage if cold water drips or splashes on hot glass. Therefore, many of our spotlights and floodlights contain caution statements on the package warning about use outdoors to alert you to the possibility that if water splashes or drips on the glass when the glass is warm or hot the glass could break. If you want to use this lamp in an outdoor application, the possibility exists that water could drip or splash on the glass. Thus, an outdoor lighting fixture that protects the glass from dripping or splashing water should be installed.
7. Does an MR16 halogen lamp provide much UV?
Tungsten filament lamps, such as halogen and incandescent, provide minimal UV. GE's ConstantColor® MR16 lamps are made using special quartz, which has properties that enable it to filter out nearly all of the UV portion of the spectrum.
8. What is the coating used on infrared halogen PAR lamps?
The coating used on infrared halogen PAR lamps is made from tantala and silica. It is applied only to the outside of the bulb.
9. What types of halogen products are the best for reducing heat (infrared radiation)?
GE's ConstantColor™ lamps with dichroic coatings and halogen-IR lamps are the two best halogen options for reducing IR. The halogen-IR lamps have a coating on the filament tube to redirect the IR back to the filament to make the lamp emit light that is not only cooler, but also brighter for the same amount of energy as a comparable halogen lamp. In the case of our MR16 ConstantColor™ lamp, a special dichroic reflector allows two-thirds of the infrared radiation emitted by the filament to be directed back toward the base of the lamp. Thus, the forward beam of light contains up to 66% less heat.
10. I can't find the lumen rating on my MR16/MR11 lamp. Why?
MR11s and MR16s are a directional light source, and are only measured by center beam candle power, which is the average amount of luminous intensity, or how bright the light is, at the center of the beam.
11. What is special about HIR lamps?
HIR stands for Halogen-IR. An IR (infrared) coating is placed on the filament tube of some of our halogen lamps. This multiple layer coating not only absorbs UV but also re-directs IR (heat) back onto the filament. By re-directing the IR back to the filament, the lamp produces more light for the same amount of energy and the amount of heat generated by the lamp is reduced when compared to standard Halogen products. Therefore HIR saves money by:
- Lowering UV emissions
- Reducing energy costs
- Lessening A/C loads
- Improving preservation of perishable displays
12. How can I get lighting product catalogs and sell sheets?
The Literature Library contains downloadable PDFs, including the latest full-line catalog and product sell sheets with in depth product specifications.