Halogen lighting was invented to address the problem of short life spans in incandescent bulbs (halogen lights are a special type of incandescent bulb). In an incandescent lamp, the thickness of the filament may vary. The resistance of the filament is higher at the thinner portions, causing those areas to be hotter than the thicker parts of the filament.
The rate of tungsten evaporation will be higher at these points due to the increased temperature, causing the thin areas to become even thinner, creating a runaway effect until the filament fails.
A halogen lamp creates an equilibrium reaction in which the tungsten that evaporates when giving off light is re-deposited at the hot spots. This allows halogen lamps to be run at higher temperatures, allowing for higher luminous efficacy and brightness.
A halogen bulb is often 10 to 20 percent more efficient than an ordinary incandescent bulb of similar voltage, wattage, and life expectancy.
Halogen bulbs may also have two to three times as long a lifetime as ordinary bulbs, depending largely on whether a premium-fill gas (krypton or xenon) or argon is used.
Styles and Cost
From $60 to $600, you can find halogen vanity lighting to fit your needs. The lights come in styles that fit above a mirror, on the side of a mirror, or as sconces. From nickel finishes with frosted glass, to polished finishes with matte glass, almost every shape and size is out there.
Proper bathroom lighting involves using a combination of lighting techniques to achieve a balance between task lighting and ambient lighting. The best mirror lighting surrounds the face with light. This provides light from all sides, minimizing shadows under the chin, eyes, cheeks, and forehead. Ambient lighting comes from the vanity lights.
Choosing the proper bathroom lighting can reduce bothersome glare, produce enough light for fading eyesight and provide a safe night light. Halogen lighting is crisper, making your skin look more like its real colors in the mirror. In this way, halogen lights are effective as task lighting as well.
Task lighting should be concentrated around mirrors. The best way to evenly distribute light is to put vertical fixtures or sconces at eye level on each side of the mirror, 36 to 40 inches apart, and a fixture above the mirror, 70 to 80 inches from the floor. Vanity-style lighting should be at least 150 watts, spread over a fixture, that’s at least 24 inches long.