Halogen Light Bulb Versus Incandescent Light Bulb

The conventional incandescent light bulb has been around for many years and has proven to be a reliable lighting technology. The halogen bulb is a special type of incandescent bulb that is often used for floodlights, spotlights, and reading lights. Here is how these two light technologies compare.

Halogen Light Bulb

A halogen light bulb is a special type of incandescent bulb in which a halogen gas such as iodine or bromine is added to the inert fill gas inside the bulb. The halogen is key to extending the life of the bulb. Halogen bulbs have a higher gas pressure and operate at a higher temperature than non-halogen bulbs.

Halogen bulbs are smaller and have thicker walls than non-halogen incandescent bulbs of comparable wattage. The bulb shapes are usually tubular and sometimes globular.

Incandescent Light Bulb

An incandescent light bulb consists of a filament of coiled tungsten wire housed inside a glass bulb. When an electric current is passed through the filament, it heats to a high temperature until it glows, thereby producing light. The bulb is filled with an inert gas, typically argon, to prevent combustion and slow down evaporation of the tungsten filament.

 Incandescent light bulbs are the most common of lights and easy to find in a variety of styles and wattages. Most bulbs for household use range from 15 to 150 watts and typically have a rating of 750 or 1000 hours.

Light Quality

Halogen bulbs produce a brighter, whiter light than non-halogen bulbs. This makes them popular for display lighting because colors appear more vibrant. Many also find that the bright light of a halogen lamp reduces eyestrain when reading. Halogen bulbs are favored over non-halogen incandescent bulbs for floodlights and spotlights because they are brighter, more energy efficient, and last longer.

Non-halogen incandescent lights give off a softer, yellower color than their halogen brethren. This makes them a better choice for mood lighting and general purpose lighting of bedrooms, and other living areas. Many people find halogen light to be too harsh in such applications.

Energy Efficiency

In their tests, the California Energy Commission has found some halogens that use up to 20 percent less energy than incandescent lights. And there is a new halogen bulb design that is up to 30 percent more energy efficient than a conventional incandescent bulb. However, neither type of light is very energy efficient compared to modern compact fluorescent or light-emitting diode technologies.

Life Span

Halogen bulbs can last approximately twice as long as conventional incandescent bulbs of comparable wattage and color temperature due to the regenerative properties of the halogen gas. As with a conventional bulb, the tungsten filament evaporates when the light is on, but instead of being deposited on the inner surface of the bulb, the tungsten particles combine with the halogen gas and are redeposited on the filament. This delays both filament failure due to tungsten thinning as well as darkening of the bulb.

A halogen bulb can be designed to match the life of a conventional incandescent bulb of comparable wattage but will operate at higher filament temperatures with greater luminance and efficiency.


Because they are more costly to manufacture, halogen bulbs are considerably more expensive than non-halogen incandescent bulbs of comparable wattage. A 4x price difference is not uncommon.

Safety Considerations

Halogen lights are hotter than regular incandescent lamps so protective grids, grills, and housings are often employed to reduce fire and burn hazards. Although conventional incandescent bulbs do not get as hot as halogen bulbs, they typically lack the safety enclosures used to protect halogen bulbs. For this reason, it is important to prevent bulb contact with skin, cloth, and other flammable materials.