Small, easy to use and brilliant light sources, halogen lamps are a popular alternative to the incandescent lamp and a particularly interesting option for design-oriented applications.

Halogen lamps are a further development of the incandescent lamp – another member of the family of thermal radiators that generate light by heating a tungsten filament. Halogen lamps operate much more efficiently than incandescent lamps: their bulbs are filled with halogen gas, which reduces wear on the white-hot tungsten filament and keeps the quartz bulb clean.

Advantages of halogen lamps

The popularity of halogen lamps is due to their advantages in comparison with ordinary incandescent lamps:

• relatively good luminous efficacy of 25 lm/W
• a life up to 5,000 hours, which is considerably more than a conventional incandescent lamp (1,000 hours)
• constant luminous flux due to the fact that tungsten particles are not deposited on the bulb
• very good colour rendering (R_a ≥ 90)
• brilliant warm-white light colour.
  
  

Halogen lamps are available as high-voltage models for 230 V mains voltage and as low voltage lamps. All halogen lamps are dimmable; in the case of low-voltage models, dimmers and transformers need to be compatible.

High-voltage halogen lamps

Halogen lamps for mains voltage are available in numerous designs. Energy-saving lamps contain xenon; double-ended linear lamps (R7s base) feature the same energy-saving IRC-technology as low-voltage models.

High-voltage halogen lamps with screw base are simply fitted in place of incandescent lamps. Available with a large (E27) or small (E14) screw base, they come with clear or matt bulbs and are also on the market as pressed-glass reflector (PAR) lamps. Double-ended (R7s base) linear high-voltage halogen lamps provide mostly wide-angled lighting. Reflector lamps and lamps without reflector – both with pin base – are an alternative to low-voltage lamps of the same design. Because they operate on mains electricity, they do not require an upstream transformer.

As of September 2009, less energy-efficient halogen lamps will suffer the same fate as general-service tungsten filament lamps: they will not be allowed to be placed on the market. This is stipulated in Regulation 244/2009 "Ecodesign requirements for non-directional household lamps", which enters into force on 13 April 2009. Up to 2016, only halogen lamps qualifying for Energy Efficiency Class B or C will be permitted; beyond that, with two exceptions, C Class lamps will also be removed from the market.

Halogen lamps with reflector are not yet affected by these regulations.

Low-voltage halogen lamps

The low-voltage halogen lamp – the diminutive light source delivering lots of light – has been around since the 1980s. The star of wire and rod systems, it always features a pin base. Low-voltage halogen lamps for 6, 12 or 24 V require a transformer.

Low-voltage lamps are available with or without metal or mirrored glass reflectors in various beam spreads and with different-sized reflectors. With cool beam reflector lamps, two-thirds of the radiant heat is emitted at the back. Heat-sensitive objects such as museum exhibits are thus protected from intense heat.

As of September 2009, all matt low-voltage halogen lamps will be removed from the market. The phase-out will progress in stages through to 2016. Low-voltage halogen lamps with reflector are not yet affected by the new regulations.