With the spread of LED technology in lighting, it makes sense for individual consumers to understand more about measurement units as Kelvin, Lumen or Candela. We are happy to provide short explanations of the units we use on this website.
W as Watt. The unit tells you how much energy a device consumes, be it a vacuum cleaner, a hairdryer or a light bulb. Within one type of light source, a bulb consuming more watts will be brighter. However, new lighting technologies as LEDs need much less energy to provide the same brightness.
lm as Lumen. This unit describes the luminous flux, measuring the amount of visible light emitted by a source, that is, in a general, simplified sense, the brightness.
K as Kelvin: Kelvin is the unit for the colour temperature. Values below 2000K stand for a warm, reddish colour temperature. Values of more than 4000K stand for cool, blueish light. A candle flame has about 1500K, a 60 watts incandescent bulb approximately 2700K, a neutral-white compact fluorescent bulb about 4000K, and the lighting coming from a clear blue sky has over 15000K. For use in homes, a high value is not necessarily better in this case! Blueish white light makes you feel wide awake, redish warm light is said to enhance relaxation and rest.
h as Hour. This unit is used to inform about the mean lifetime of a light source. Please note that by definition of the light bulb manufacturing industry, at this moment 50% of the light sources of a test batch are still working. That means, some bulbs will stop working earlier, some later.
cd as Candela: You find this measurement unit on light sources for directed light, often instead of the unit for Lumen. The unit describes the luminous flux (measured in Lumen) emitted in a given direction, or the brightness of a light source with a reflector - again, in a general, simplified sense.
EEC stands for energy efficiency class or for European Economic Community. The formula to calculate the energy efficiency classes (A++ - E) is defined by the EU.
“Compatible with bulbs of the energy classes A++ - E”. When we state that one of our lighting fixtures is “compatible with bulbs of the energy classes from … to …”, it means that light sources of those classes which fit into the specific lamp from our collection are available on the market. Please note that it does not mean that the lighting effect, the brightness or the colour temperature are the same or similar. But as the quality of LED light sources is improving fast, we expect even better LED retrofitbulbs will become available in the near future. We are constantly monitoring what is on the market (in Europe).
What does Zhaga Book 3 mean in terms of LED bulbs: Zhaga is the name of a consortium for the development of industry standards for LED lamps. Book 3 is a type of LED specification. For you as a user the Zhaga-conformity means there will be suitable replacement parts for the LED module in the future. If necessary a specialist can replace the module with a current LED.