- What is an LED light?
- In what stage is the development of LED technology today?
- In what kind of applications are LEDs used?
- Can LED street lights efficiently replace HID lamps?
- Is it possible to just replace an old bulb with an LED bulb and not with the whole LED luminaire?
- How can I differ between low quality and high quality LED luminaire?
- Where can the LED street lights be seen?
- What is the investment cost of LED street luminaires compared to other technologies?
- What are the main disadvantages of LED technology?
- What is the lifetime of LED luminaires?
- Is there a warm-up time needed when switching on a LED luminaire?
- How mechanically durable is a LED luminaire?
- How accurate is the color reproduction of LED light?
- Can LEDs be dimmed?
- Does dimming LEDs decrease their lamp life?
- What does the IP and IK rating means
- Do LED luminaires contain any harmful substances?
- Is there any infrared radiation coming out of LED luminaires?
- How is white ultraviolet radiation in LED luminaires?
- How much can I save with LSL® lights?
What is an LED light?
An LED light is a solid-state lamp that uses light-emitting diodes (LEDs) as the source of light. It is a small electronic device (a semiconductor diode) that emits light when electricity passes through it. It is one of the most efficient and prosperous light sources available on the world market. According to the latest research and further development advances of the LED industry, LED light technologies will be the leading lighting force in the future.
In what stage is the development of LED technology today?
LEDs are dramatically increasing light output, efficiency, reliability and are becoming increasingly more brighter. The lumen output of LEDs has almost doubled in the last two years. At the end of 2009 the LED technology was mature enough to enter the high demanding market of outdoor illumination and to successfully compete with existing street lighting technologies.
In what kind of applications are LEDs used?
LED technology has been used for several decades in various applications. White LED lamps have achieved market dominance in applications where high efficiency is important at low power levels. Some of these applications include flashlights, solar-powered garden or walkway lights, and bicycle lights. Monochromatic (colored) LED lamps are now commercially used for traffic signal lamps, where the ability to emit bright monochromatic light is a desired feature, and in strings of holiday lights. LEDs are widely used in automotive industry, military and yachting lighting. Its use in domestic electronic appliances and high tech devices is rising. LED lights have also become very popular in gardening and agriculture by 2010. First used by NASA to grow plants in space, LEDs came into use for home and commercial applications for indoor horticulture (aka grow lights).
The incredible rapid progress of LED technology in the last few years enabled LEDs to become appropriate for use in general and outdoor lighting applications. Latest LED technologies used in LED luminaires are not only satisfying the needs of quality outdoor and general illumination but are already exceeding all other technologies in all parameters.
Can LED street lights efficiently replace HID lamps?
Yes, LED street lights can efficiently replace and outperform HID lamps with numerous advantages (longer lifetime, directional light distribution, high light uniformity, no maintenance, durability, high color rendering index, etc.). All this without emissions that would be harmful to the environment.
Is it possible to just replace an old bulb with LED bulb not with the whole LED luminaire?
Some manufacturers are even producing LED bulbs, but the fact is that even if an LED bulb fits into an existing luminaire, the overall lighting output and performance cannot cope with the LED luminaire. The housing of LED luminaire is designed especially for the needs of LEDs to maximize its efficiency, performance and life-time. On the other hand traditional housing doesn´t offer the optimized working condition, especially not from the thermal management point of view.
How can I differ between low quality and high quality LED luminaire?
While choosing the right LED solution, you have to be aware, that LED technology has progressed rapidly in the past few years, that not all LED luminaires are created equal and that some manufacturers are offering extremely low cost options, which are inferior and of poor quality. To be really sure that technical claims of the manufacturer are true, you have to inspect and test the product carefully. Only the technical characteristic of an LED cannot define the performance of an LED luminaire, since the system is composed from many critical components (like optics, thermal management, driver etc.) which are the keys to optimized overall performance and efficiency.
You can recognize some low quality LED solutions by some common characteristics:
- unpleasant pale blue shine of light (color temperature 5.500 K and more)
- open casings and visible cooling ribs that indicate weakly solved problem of light heating (accumulating dirt on cooling ribs mean more maintenance cost, while openings in casing cause malfunction of electronics and reduced life expectancy)
- low quality components (optics, LEDs, driver, etc.) assembled together in manufacture with lack of technical expertise and quality control can cause uneven distribution of light beam, poor light and energy efficiency, glare etc., etc.
Always be sure that the manufacturer technical claims are not misleading but are verified with valid, acceptable and verifiable certificates. Also be sure that the manufacture has a solid and reliable background/history and can fulfill its warranty claims together with full customer support.
Where can the LED street lights be seen?
LED street lights have been installed or announced for installation in several large cities as well as smaller cities throughout the world (Boston, Worcester, Cleveland, Varna, Toronto, New York, Budapest, Los Angeles,…). Also a number of reports on the results of pilot projects for municipal outdoor lighting are available. Most of the cities that are following the policy of »green cities« have implemented LED technology in their future city development.
What is the investment cost of LED street luminaires compared to other technologies?
The cost of LED street luminaire is higher than that of other technologies, but when considering all the benefits and cost savings you will acquire with the right LED solution, there is no other serious alternative. Due to high energy efficieny your electricity bills will be drastically reduced, you will have no maintenance cost, you will lower your carbon emission and most important you will enjoy these benefits for decades, while return on investment will be realized in less than 2 years in most cases. With a solid financial plan your cash outlay will be minimal and with the realized savings may not cost anything at all compared to what you are utilizing at the present time.
What are the main disadvantages of LED technology?
The biggest disadvantage of LED technology is lack of education and knowledge about the technology itself and lots of poor quality solutions available on the market. There is a lot of misleading information on the market, coming from two main sources:
- manufacturers with low quality solutions, which are misleading the consumer with false technical characteristics and claims
- competitors which sell inefficient lighting technologies, which will soon be banned, so they can deplete existing inventories.
There are also a number of companies who claim to be original manufacturers but instead buy inferior quality LED luminaires from countries which mass produce the product, put their own brand on products, change origin and then sell to unsuspecting customers for a higher price.
Some street lighting tests were made while using old immature LED technology before the year 2009 when LED technology was mature enough to seriously compete with other street lighting technologies. Results of these studies are not showing the real condition of LED street light technology today.
The result of all this confusion and organized chaos, is that the current market is experiencing unjustified doubt about the LED technology that is currently on the market. Who do you believe ? For the customer this is an extremely valid question. The weakness is not in technology but in cheap quality products and lack of knowledge.
Customers should always be careful and choose only verified high quality LED street light solutions from reputable manufacturers with solid backgrounds and proven history. While checking street lighting tests and reviews, you should always check which product was reviewed and from which year the product is available to avoid possible wrong conclusions.
What is the lifetime of LED luminaires?
LEDs do not burn out like incadescent light bulbs. Instead LEDs over their lifetime simply get progressively dimmer until they do not emit enough light to be useful. LED is considered to be no longer useful when it is emitting only 70% of the amount of light that it originally emitted. The time when 30% of lumen depreciation occurs is considered to be the "lifetime" of an LED.
High quality LED luminaires can go up to 100,000 hours under good working conditions. The officially acknowledged standard for life time of high quality LED luminaires worldwide is 50,000 hours. They are still working after that time and can go up to 100,000 hours but with lower lumen output. 100,000 working hours means a lifetime between 11 and 34 years depending on how long a LED luminaire is working every day.
| Working hours per day | Life time of LED luminaire |
|---|---|
| 8 hours | 34.2 years |
| 10 hours | 27.4 years |
| 12 hours | 22.8 years |
| 16 hours | 17.1 years |
| 20 hours | 13.7 years |
| 24 hours | 11.4 years |
| Street lighting technology | Life time in hours |
|---|---|
| LED lights |
50,000 – 100,000 |
| Incadescent lights | 1,000 – 5,000 |
| Mercury vapor lights | 12,000 – 24,000 |
| Metal halide lights | 10,000 – 15,000 |
| High pressure sodium (HPS) | 12,000 – 24,000 |
| Low pressure sodium (LPS) | 10,000 – 18,000 |
| Fluorescent light | 10,000 – 20,000 |
| Compact fluorescent light | 12,000 – 20,000 |
| Induction light | 60,000 – 100,000 |
Is there a warm-up time needed when switching on a LED luminaire?
No. LEDs do not have the long warm-up times, which many people find annoying about CFLs (compact fluorescent lamps). Instead, the light from LEDs shines at full brilliance as soon as the switch is turned on. Also cold temperatures do not affect the performance of LED luminaire.
How mechanically durable is a LED luminaire?
Unlike other light bulbs that use fragile filaments (especially incandescent light bulbs) LEDs are vibration and shock resistant. While vibration or shock easily breaks the fragile filament in an incandescent bulb and the glass tubing of a fluorescent lamp, LEDs tolerate vibration exceptionally well because they do not use filaments. Energized components of the LED are well separated from the outer surface with high quality insulation. The electrodes are embedded in the bulb matrix and the driver electronics are encased in its shell. A layer of interface material between the LED and the heat sink ensures that no current can leak to the heat sink. This make LED luminaire a completely solid-state technology which are virtually indestructible under normal circumstances.
How accurate is the color reproduction of LED light?
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. White LEDs offer the industry's highest CRI (80-90), making objects to be illuminated appear more natural and vibrant, which increases overall safety.
Can LEDs be dimmed?
The forward current is proportional to the light output of an LED over a large operating range, so dimming can be achieved with reductions in the forward current. Because LEDs can be rapidly switched on and off with no harmful effects, dimming can be accomplished using a method called pulse width modulation. By adjusting the relative duration of the pulse and the time between pulses, the apparent intensity of the LED can be dimmed. This is done with direct digital control, which enables frequency high enough that LED appears to be continuosly lit without flickering.
Does dimming LEDs decrease their lamp life?
It has been observed that when some fluorescent lighting systems are frequently dimmed, they might exhibit less reliability and lamp life. This is not the case for LEDs. Life and light output degradation are determined largely by the junction temperature, with higher temperatures resulting in reduced life characteristics. Since dimming, either by reducing current or by pulse width modulation, results in lower overall junction temperatures, it will have no negative impact on LED life, it might even extend life.
What does the IP and IK rating means?
IK – protection against mechanical impacts
The European standard EN 62262 (the equivalent of international standard IEC 62262:2002) relates to IK ratings. This is an international numeric classification for the degrees of protection provided by enclosures for electrical equipment against external mechanical impacts. It provides a means of specifying the capacity of an enclosure to protect its contents from external impacts.
EN 62262 specifies the way enclosures should be mounted when tests are carried out, the atmospheric conditions that should prevail, the number of impacts (5) and their (even) distribution, and the size, style, material, dimensions etc. of the various types of hammer designed to produce the energy levels required.
| IK number | Level of protection | Equivalent impact |
|---|---|---|
| 00 | No Protection | No test |
| 01 | Protected against energy at the impact of 0.15J | Drop of 200 g object from 7.5 cm height |
| 02 | Protected against energy at the impact of 0.20J | Drop of 200 g object from 10 cm height |
| 03 | Protected against energy at the impact of 0.35J | Drop of 200 g object from 17.5 cm height |
| 04 | Protected against energy at the impact of 0.5J | Drop of 200 g object from 25 cm height |
| 05 | Protected against energy at the impact of 0.7J | Drop of 200 g object from 35 cm height |
| 06 | Protected against energy at the impact of 1J | Drop of 500 g object from 20 cm height |
| 07 | Protected against energy at the impact of 2J | Drop of 500 g object from 40 cm height |
| 08 | Protected against energy at the impact of 5J | Drop of 1.7 kg object from 29.5 cm height |
| 09 | Protected against energy at the impact of 10J | Drop of 5 kg object from 20 cm height |
| 10 | Protected against energy at the impact of 20J | Drop of 5 kg object from 40 cm height |
IP – Ingress Protection Rating
The IP Code (or International Protection Rating, also interpreted as Ingress Protection Rating) consists of the letters IP followed by two digits and an optional letter. As defined in international standard IEC 60529, it classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in electrical enclosures The digits (characteristic numerals) indicate conformity with the conditions summarized in the tables below. Where there is no protection rating with regard to one of the criteria, the digit is replaced with the letter X.
IP First number - Protection against solid objects
| IP first number | Protection level – solid objects |
|---|---|
| 0 | No special protection |
| 1 | Protected against solid objects up to 50 mm, e.g. accidental touch by persons hands. |
| 2 | Protected against solid objects up to 12 mm, e.g. persons fingers. |
| 3 | Protected against solid objects over 2.5 mm (tools and wires). |
| 4 | Protected against solid objects over 1 mm (tools, wires, and small wires). |
| 5 | Protected against dust limited ingress (no harmful deposit). |
| 6 | Totally protected against dust and contact. |
IP Second number - Protection against liquids
| IP second number | Protection level - liquids |
|---|---|
| 0 | No protection. |
| 1 | Protection against vertically falling drops of water e.g. condensation. |
| 2 | Protection against direct sprays of water up to 15o from the vertical. |
| 3 | Protected against direct sprays of water up to 60o from the vertical. |
| 4 | Protection against water sprayed from all directions - limited ingress permitted. |
| 5 | Protected against low pressure jets of water from all directions - limited ingress. |
| 6 | Protected against temporary flooding of water, power jets from all directions limited ingress permitted. |
| 7 | Protected against the effect of immersion between 15 cm and 1 m |
| 8 | Protects against long periods of immersion under pressure |
Do LED luminaires contain any harmful substances?
No, LEDs contain no harmful substances. Mercury is not used in LEDs, relieving you from the environmental hazards which are present with disposing of burnt-out fluorescent, metal halide, and high pressure sodium light bulbs.
Is there any infrared radiation coming out of LED luminaires?
White LEDs do not emit infrared radiation (no beam heat) so, the beam of light produced by a white LED does not contain any heat. This makes LEDs ideal for shallow ceiling downlighting and display lighting.
How is white ultraviolet radiation in LED luminaires?
White LEDs do not produce any ultraviolet (UV) light even though all other natural and artificial light sources do. This has many benefits:
-
Limited Fabric Fading
When using white LED light fixtures, there will be minimal fading and deterioration of fabrics, documents, or artwork due to exposure to the white light from LEDs. -
Better for Fruits & Vegetables
Unlike light sources like metal halide, LEDs do not radiate high levels of UV rays. While it is common knowledge that heat can speed up food’s spoilage rate, it is lesser known that high UV levels can actually decrease the nutrient levels in food. Thus, using LEDs to light the produce in a super market, for example, may not only be energy efficient, it may also help the produce to maintain higher nutrient levels. -
Do Not Attract Bugs
Since white LEDs do not emit ultraviolet light (the invisible portion of the spectrum just beyond visible violet) light fixtures using white LEDs do not attract bugs.
How much can I save with LSL® lights
Savings while replacing inefficient old lamps with Aerolite LSL® LED lights vary depending on wattage and lifetime of currently installed lights. Since LSL® has a minimum lifetime of 60,000 hours (and can easily go up to 100,000 hours), has low wattage and requires almost no maintenance, total savings in electricity and maintenance can be up to 90% compared to old lights. All this can be achieved while improving illumination performance at the same time. Also CO2 emissions will be drastically reduced and considering the fact that LSL® is completely environmentally friendly, by deciding for Aerolite LSL® you will contribute to the protection of the environment.
Examples:
Replacement of 30 pieces HPS lights to Aerolite LSL®30 lights
$24,025 (€18,450) total savings
81.9 lb (37,170 kg) total CO2 emission reduction
Replacement of 100 pieces HPS lights to Aerolite LSL®90 lights
$152,748 (€117,300) total savings
999 lb (453,120 kg) total CO2 emission reduction
Replacement of 500 pieces HMQ lights to Aerolite LSL®30 lights
$662,169 (€18,450) total savings
3.969 lb (1,805,400 kg) total CO2 emission reduction
Replacement of 1000 pieces HMQ lights to Aerolite LSL®90 lights
$6,606,070 (€5,073,000) total savings
60.717 lb (27,541,200 kg) total CO2 emission reduction
Replacement of 2000 pieces HMQ lights to Aerolite LSL® 30 lights
$4,414,464 (€3,390,000) total savings
33.558 lb (15,222,000 kg) total CO2 emission reduction
Replacement of 200 pieces mercury lights to Titanium LCL®90 lights
$964,931 (€741,000) total savings
8.819 lb (4,000,200 kg) total CO2 emission reduction