To help you gain a quicker and more thorough understanding of LED lightings, we have compiled some of the most frequently asked questions and provided the answers for you here. Feel free to contact INLEDS Lighting and we will be glad to answer your questions and help you learn the best methods and most efficient ways to creatively light up your home or business.
We have compiled some of the most commonly used terms in the LED lighting industry and their definitions to help you fully understand the language and what you are purchasing.
Color Temperature (CCT) is a description of the warmth or coolness of a light source, i.e. light in a range going from red to orange to yellow to white to blueish white. Color temperature is conventionally expressed in “Kelvin”, using the symbol K, on a scale from 1,000 to 10,000. Typically, Kelvin temperatures for commercial and residential lighting applications fall somewhere on a scale from 2000K to 6500K.
The effect of a light source on color appearance is expressed in the Color Rendering Index (CRI), on a scale of 0-100. Natural outdoor light has a CRI of 100 and is used as the standard of comparison for any other light source. The higher the CRI rating, the higher closer the light compared to natural light. CRI is normally taken in controlled laboratory to give a more accurate reading. CRI rated above 80 is excellent for home and commercial use which reflects color truly and naturally.
In photometry, luminous flux is the measure of the perceived power of light, to reflect the varying sensitivity of the human eye to different wavelengths of light.
The international (SI) unit of luminous flux is the lumen (lm). One lumen is defined as the luminous flux of light produced by a light source that emits one candela of luminous intensity over a solid angle of one square radian.
The lumen (lm) is the international (SI) derived unit of luminous flux, a measure of the total quantity of visible light emitted by a source per unit of time. Lumens are related to lux in that one lux is one lumen per square meter. LED lightings are commonly labelled with their light output in lumens.
The lux (lx) is the SI derived unit of illuminance and luminous emittance, measuring luminous flux per unit area. It is equal to one lumen per square meter.
For example, 500 lux might be bright enough for a home kitchen with light fixtures with an output of 12000 lumens, but to light a factory floor with much larger area to the same level of lux requires a greater number of lumens.
The Beam Angle of a lamp is the angle at which the light is distributed or emitted.
The lighting industry’s uniform formula to determine the beam angle: the light output (lumens) is measured at the center of the beam and then light strength (intensity) is measure out from the center until it is 50% of the intensity level. The beam angle is determined in degrees: the most common designations for light beams are Spot (7 to 15 degree), Flood (20 to 35 degrees), Wide Flood (35-50 degrees), and Very Wide Flood (50-120+ degrees).
The power output of lighting is determined in Wattage, while LED lighting’s luminous efficacy is determined by lumen/watt (lm/w). Lumen and wattage are important concepts to understand when considering the energy use of a light source. Simply put: a LED light uses far less energy (watt) to produce the same light output (lumen) than traditional lighting.
A light fixture can be connected to devices called dimmers/dimming drivers to lower the brightness of light to various luminous level. By changing the voltage waveform applied to the lamp, it is possible to lower the intensity of the light output. LED lighting dimming commonly works with dimming systems, such as 0-10V Lighting Control, DMX512, DALI etc.
IP is an acronym “Ingress Protection”. It is a measurement of the protection an item will have against solid objects (dust, sand, dirt, etc.) and liquids. An IP rating is comprised of 2 numbers. The first number (0-6) refers to the protection against solid objects (dust, debris etc.) and the second number (0-8) refers to protection against liquids and moisture.
General indoor LED lightings are IP20-IP40; while for outdoor lightings there are IP65 (Water resistant), IP66 (Water resistant against powerful water), IP67 (Water resistant plus temporary submersion).