Halogen Bulbs

Halogen bulbs work by passing electricity through a tungsten filament. The filament is inside a tube containing halogen gas. A chemical reaction takes place which detaches the tungsten from the wall and deposits it on the filament; this will increase the life of the bulb, making it an ideal economic solution.

For the chemical reaction to take place in a halogen bulb, the filament needs to be hotter that what is needed in other types of bulbs such as incandescent bulbs. This can be a real advantage as the hotter the filament, the more powerful and brighter white light is then produced. However the hotter the filament, the more the tungsten in the bulb is evaporating. In most cases, a denser and more expensive gas called krypton may be used, this will help slow down the evaporation. 

When handling these types of bulbs, you will have to bear in mind the sensitivity of the bulb when touching it. The oils from your fingers will weaken the glass and eventually shorten the bulbs life. This is an issue in most cases, as can cause the bulb to burst when the filament burns out.

 

To summarise the pros and cons...

Advantages:

•  Halogen is more efficient than other bulbs.  
•  Has a longer life than incandescent bulbs.
• Small in size.   
• Halogen bulbs are dimmable adding that extra feature.

 

Disadvantages: 

•  Halogen bulbs are more expensive.
•  Burn at a much higher temperature.