Small but effective
At a height of between 8 and 13 cm, metal halide lamps, a type of high-intensity discharge lamps (HID), are extremely small but they emit a considerable amount of light and provide an excellent colour definition. The almost punctiform light source emits vibrant light and casts defined shadows, creating an atmospheric ambience.
Its colour rendering
=95, meaning that a good result is achieved. Furthermore, metal halide lamps are also extremely energy efficient and durable. They save approximately 85% of energy compared to incandescent lamp and have a service life of up to 6,000 hours, equating to 5.5 years if used for three hours a day.
After being switched on, it takes approximately 2 minutes for the metal halide lamps to reach full brightness
. After being switched off, metal halide lamps must be left for a few minutes to cool down before they can be reignited. However, sophisticated (and accordingly expensive) control equipment allows for an immediate reignition of these lamps.
Therefore, it is usually inadvisable to use these lamps in conjunction with motion detectors. It is recommended to use metal halide lamps in conjunction with a ballast units, which are more efficient, convenient and safer than traditional control equipment. They consume less energy, prolong the lamp life, maintain an almost constant light temperature throughout the life of the lamp and automatically switch off the lamp at the end of its service life.
Metal halide lamps therefore provide ideal illumination for areas requiring both long periods of illumination and excellent quality lighting, such as garden areas or exterior walls of buildings. In the commercial sector, these lamps are often used to illuminate goods in store windows or display cabinets as well as to provide illumination in office premises.
Metal halide lamps (HIT)
These are refined mercury vapour lamps with considerably better luminous efficacy and excellent colour rendering of Ra
=80-95. Some models achieve a luminous efficacy of up to 100 lm/W and have an incredibly long service life.
High-pressure sodium vapour lamps
With a luminous efficacy of up to 150 lm/W and an extremely long service life, these lamps outperform all other high-pressure discharge lamps. However, in view of their low colour rendering (Ra
=20-39), these lamps are used primarily for exterior lighting and in large industrial buildings.
Mercury vapour lamps
These are the only discharge lamps that do not require an ignitor. Compared to other discharge lamps, the luminous efficacy, efficiency and colour rendition (Ra
=40-49) are unremarkable. They are used primarily for street lighting and for the illumination of industrial buildings.
Please also read the information on LED