Nemalux General Education
Illuminate the Process with the Future of Intelligent Lighting
Nemalux has developed energy efficient, robust, waterproof and hazardous location approved luminaries. These products are designed to provide lighting for areas where water, vibration, maintenance or temperature negatively affects conventional illumination. Nemalux combines the long-life and reliability advantages of Light Emitting Diode (LEDs) with the brightness of conventional lighting. Solar powered options are available.
The Nemalux luminaries were originally developed for lighting in an industrial location. The Nemalux brand was developed to filling a low profile, hazardous location niche that florescent and incandescent lights could not., making the Nemalux brand very high quality, durable and safe. Some applications include 12-24VDC installations, compressor sites and oil and gas refineries. The Nemalux product offering includes single LED spots, linear luminaries, indicators, solar powered luminaries and area lighting luminaries.
New technology LEDs offer up to 120 lumens per watt making some of the luminaries a replacement to 150 Watt High Pressure Sodium lighting. A variety of high intensity LED colors are available for specific applications.
Most of the Nemalux luminaries are designed for low voltage power. The reasons for using low voltage are: with the following advantages:
- LEDs are inherently low voltage devices powering them with low voltage DC makes the system more efficient.
- Low voltage reduces cabling costs.
- Low voltage is electrically safer; there is a lower probability of arcing or sparking.
- Low voltage is ideal for solar powered application or battery based systems.
Quality White Light
Quality, when used to describe the white light from LEDs, refers to the consistence consistency of color in the beam of light and correlated color temperature (CCT) variations over time and to the temperature and CCT variation between individual products.
How are white LEDs created?
There are currently two ways to make white light with LEDs. One method mixes multiple wavelengths of different LEDs to make white light (i.e. RGB), allowing the lighting designer to tune the white light to a specific color temperature. The second method uses a blue Indium-Gallium-Nitride (InGaN)LED with a phosphor coating to create white light. This is the method that results in the more commonly seen “white LED”.
Wide range of color temperatures and wavelengths (color)
Today, LEDs offers the full spectrum of white lighting from 2760K-10,000K. Our product offering of cool-white and warm-white LEDs enables lighting designers and specifies to create lighting solutions with consistent color temperatures.
LEDs also emit monochromatic light with the main ones being the three primary colors of red, green and blue. There are many standard LED colors. The Nemalux RGB luminaire can achieve also any color by combining the three primary colors of Red, Green and Blue these three colors.
High Color Rendering Index (CRI)
Color Rendering Index or CRI is the calculated rendered color of an object. The higher the CRI (based upon a 0-100 scale), the more natural the colors appear. Natural outdoor light has a CRI of 100. Typically high quality LEDs offer a CRI higher than 80.
Conformal Phosphor Coating Process
Uniform coating of the LED with phosphor is the most important step in creating a warm white LED. This eliminates the blue-ring effect common to other white LEDs and delivers the consistent white color throughout the light beam.
Lumen maintenance is simply the amount of light emitted from a source at any given time relative to the light output when the source was first measured. This is usually expressed as a percentage. If you’ve ever changed a light bulb and noticed how bright a new bulb is when compared with the older bulb, you’re seeing the effects of lumen depreciation. This steady decline over time is known as lumen maintenance (L). The materials inside the bulb will continue to deteriorate until finally the bulb will no longer emit any light. This is known as the bulb’s mortality (B). With conventional light sources, the bulb usually fails before our eyes notice the change in lumen maintenance.
LEDs also experience lumen depreciation but it happens over a much longer period of time, usually tens of thousands of hours. Compared to conventional light sources, you notice very little degradation of light. Not all LEDs deliver the same lumen maintenance. An LED is a complex package of materials that must all work together to deliver long lifetimes. Everything from the design of the chip, thermal management, optics material, phosphors and even the assembly of the entire package will affect lumen maintenance. Some LEDs demonstrate very rapid depreciation.
Figure 1. CREE LEDs vs. conventional light sources.
Lumen maintenance and lifetime are intertwined
To truly understand the life of an LED light source, the user needs to understand both mortality (B) and lumen maintenance (L). Let’s say for example you are working with LEDs that on average deliver 70% lumen maintenance at 20,000 hours (L70). This tells you to expect to receive 70% of the relative lumens after 20,000 hours. What this doesn’t tell us is what percent of LEDs are performing below this level which can affect overall system performance. To get a complete understanding of performance, the user needs to know the rated life or mortality (B) and the lumen maintenance (L) of the light source.
EDISON Retrofit LED Bulbs:
LEDs are functionally an integrated fixture/emitter ‘system’. Nemalux typically does not advise the use of an LED Edison bulb in an existing fixture as this may affect the thermal management of the light emitting diode. Inappropriate thermal management negatively effects the life time and brightness of the LED significantly.
The Nemalux team researches and designs many products. Thermal management is paramount in any high intensity LED design. In order to design a LED bulb and use it in a conventional fixture some of this thermal management must be sacrificed. This will affect the longevity and brightness of the LED. The generated heat in a confined space may also affect the internal AC-DC power supply. These are some of the engineering hurdles associated with manufacturing an Edison E27 retrofit.
The existing Nemalux luminaries luminaires support the new LED technology with appropriate thermal management in order to supply the brightest, most efficient lights with superior longevity.
New technology Light Emitting Diodes are not 100 % electrically efficient. While most of the electrical energy is converted to light some is still converted to kinetic energy (heat).
Heat generated by solid state devices and circuitry must be dissipated to improve reliability and prevent premature failure. In the case of LEDs, heat generation effects lifetime and brightness adversely. Techniques for heat dissipation can include fans, liquid cooling and typically, for LEDs, heat sinks.
Transmission of heat from a heat source (e.g. the junction of a LED) via the heat sink into the surrounding medium takes place in four successive steps:
1. Transfer from heat source to the heat sink
2. Conduction from within the heat sink to its surface
3. Transfer from surface into the surrounding medium by convection
4. Radiation depending on the nature of the heat sink’s surface
Nemalux designs fixtures to enhance the benefits of High Brightness high brightness LEDs with appropriate thermal management.