LEDs provide exciting design opportunities, and everything about this is often blocked by such words: thermal management. “When incandescent light bulbs can consume heat through radiation, LED linear high bay light produces almost no infrared heat,” said Michael Gershowitz, director of technical marketing at Prairie. Therefore, the LED must dissipate heat through thermal conduction, otherwise there is a risk that the brightness, lifetime, and color stability performance will be reduced.
However, time and market demand always have the means to push the technology to such a node, that is, thermal management will soon become a consideration in the lighting design, not an obstacle. As the LED continues to iterate, the light efficiency continues to exponentially increase. LED efficiency has now exceeded 50%, that is: they convert energy into light more than calories. Most OEMs have abandoned the existing practice of using LEDs to simply replace traditional lamps, and instead produce special and optimized lamps based on the characteristics of LED light sources. And now linear high bay lights can “work at higher temperatures for longer periods of time without losing brightness,” said Mark Hand, director of new product development and technology at Acuity Brands Lighting.
With advances in LED technology and luminaire design, manufacturers can boast more than this. Thermal management strategies have also been advancing and flourishing. Although passive cooling and active cooling are still the main choices, other innovative technologies are also being added.
More than 90% of LED linear high bay fixtures use passive heat dissipation. Under this strategy, the heat of the LED package is conducted via direct physical contact via a high thermal conductivity material heat sink. “Aluminum—usually extruded or die-cast into a finned circular shape—is a standard material for heat sinks because of its light weight, low cost, and ease of manufacture.” said Christopher Reed, Strategic Partner Manager, Xicato. . Currently, manufacturers prefer passive heat sinks for their reliability. “If not exactly the same, their performance after 50,000 hours or 20 years is not far from the first day,” Reed said.
But even a proven and proven solution can be improved. While designers optimize heat sinks by skillfully processing fin thickness and spacing, passive cooling strategies have also developed a new form of fin radiators. Unlike squeezing blades, fin radiators resemble a large number of table legs on an inverted round table, and LED devices are attached to the surface of the table.
Reed said that the columnar fins allow the heated air to rise and then flow out unimpeded around the fins. This trait has advantages in some rotatable luminaires, such as track lights. “When you tilt a standard extruded fin radiator, air cannot flow in the same direction or on the gravity axis because it always enters the fins,” said Reed.
Lighting manufacturers have also begun to turn light bodies into integrated heat dissipation solutions. With this strategy, the luminaire bezels installed in the insulated ceiling system can both be decorated and heat dissipated. Similarly, the role of those sculpted fins in the CREE Aeroblades series of street lamps is not as simple as a “vase.”
“As LEDs become more efficient, the required heat sinks are smaller and lighter,” said Mark McClear, vice president of application engineering at CREE. Along with this, materials and transportation costs will also be reduced. “When LEDs become more efficient, everything is moving in the right direction,” McClear said.
Before purchasing LED high bay light, please understand the technical parameters of LED high bay light. What does LED high bay light protection standard IP65 mean?
The code for the enclosure protection class is usually composed of the characteristic letter IP and two characteristic numbers. The first figure refers to the following: prevent the human body from touching or approaching the live parts inside the enclosure and touching the moving parts (except for smooth rotation and the like) to prevent the protection of solid foreign objects into the enclosure; the second figure refers to: preventing water from entering the enclosure The interior achieves a degree of protection against harmful levels.
The first marked number definition:
0 No protection: No special protection against people or things outside.
1 Prevent the penetration of solid objects larger than 50mm: Prevent the human body (such as palm) from accidentally touching the parts inside the lamp. Prevent intrusion of foreign objects of larger size (diameter greater than 50mm).
2 Prevent intrusion of solid objects larger than 12mm: Prevent human fingers from coming into contact with parts inside the fixture to prevent intrusion of foreign objects of medium size (12mm in diameter).
3 Prevent intrusion of solid objects larger than 2.5 mm: Prevent tools, wires, or similar small foreign objects with a diameter or thickness greater than 2.5 mm from intruding into contact with parts inside the fixture.
4 to prevent the invasion of solid objects greater than 1.0mm: to prevent the diameter or thickness of more than 1.0mm tools, wires or similar details of small foreign objects invade and touch the interior parts of the lamp.
5 Dust-proof: It completely prevents the intrusion of foreign objects. Although it cannot completely prevent dust from entering, the amount of intruded dust does not affect the normal operation of the lamp.
6 Dust-proof: It completely prevents the intrusion of foreign objects and completely prevents dust from entering.
The second tag number definition:
0 No protection: No protection.
1 Prevent drip intrusion: Drops of water (such as condensate) that are dropped vertically will not have a detrimental effect on the luminaire.
2 It can still prevent the intrusion of drip when tilted at 15 degrees: When the light is tilted to 15 degrees from the vertical, the drip will not cause harmful effects on the light.
3 to prevent the intrusion of sprayed water: prevent rain, or prevent water sprayed into the fixture with a vertical angle less than 60 degrees to cause damage.
4 to prevent the intrusion of splashing water: to prevent splashing water in all directions into the lamp to cause damage.
5 to prevent the intrusion of water: prevent water from the nozzles from all directions to enter the lamp to cause damage.
6 to prevent the intrusion of large waves: lamps installed on the deck to prevent damage caused by the invasion of large waves.
7 to prevent water intrusion when flooding: The lamp is immersed in water for a certain time or water pressure below a certain standard to ensure that it does not cause damage due to water.
8 Prevent intrusion of water when sinking: The lamp sinks indefinitely under specified water pressure conditions to ensure that it is not damaged due to water ingress.
These two figures are an important basis for the LED high-bay light protection level. For consumers, when buying LED light fixtures such as high-bay light, it is not the higher of these two numbers, the better. It must be purchase the product according to their own actual conditions.
If we want to buy something as a buyer for longer, then how can we increase the lifetime of LED high bay lighting? First, we must strictly control the quality of LED high bay packaging materials, such as conductive adhesives, silicones, and phosphors. , Epoxy, solid crystal materials, pedestals, etc. Secondly, the rational design of LED high bay lamp packaging structure, such as unreasonable packaging will produce stress, causing fractures. Then, to improve the technology of LED high bay fixture, such as curing temperature, pressure welding, sealing, loading and time, etc. must be strictly in accordance with requirements.
To increase the service life of LED high bay driving power, high-quality, long-life capacitors need to be selected as an effective way to increase the life of the driving power supply; reducing the ripple current and operating voltage flowing through the capacitor; improving the efficiency of power supply driving and reducing the heat of the components Resistance; do a good job of waterproofing and other protective measures, while paying attention to the choice of thermal plastic. Thermal design is a key factor in the life of LED high-bay lighting fixtures. With the same quality of chips placed in different designs of lamps, the life span varies greatly to as many as several times, so the design of more than one lamp does not play a decisive role in the cooling system.
LED heat dissipation generally includes system-level heat dissipation and package-level heat dissipation. To reduce the thermal resistance of lamps and lanterns, it is necessary to consider both types of heat dissipation at the same time. Package-level heat dissipation is achieved through the design of packaging materials, packaging structures, and process levels during the production of LED light sources. To achieve the purpose of heat dissipation. In terms of package heat dissipation design, there are mainly silicon-based flip chip structures, metal circuit board structures that dissipate heat, solid-state materials, and epoxy materials. System-level heat dissipation is mainly through research on related technologies, thus innovating and improving heat sinks. With the popularity of high-power LEDs, power is also increasing. At present, system-level heat dissipation mainly includes thermoelectric cooling and heat pipe cooling. And forced air cooling and other methods of cooling structure. Solving the problem of heat dissipation is an effective way to increase the lifetime of LED high-bay fixtures, so further research and innovation are needed.
LED high bay light
LED high bay lighting is an important part of the city’s industrial lighting, the traditional high bay lights using 250W, 400W metal halide lamps, 360-degree metal halide lamp light, the loss of large light caused a huge waste of energy. Therefore, the development of new high-efficiency, energy saving, long life, high color rendering index, environmental protection LED high bay lighting is of great significance to the national industrial lighting energy conservation. High bay lighting is closely related to industrial production. SHENZHEN TUBU TECH CO.,LTD LED high bay lighting has advantages such as directional light emission, low power consumption, good drive characteristics, fast response, high seismic resistance, long service life, and environmental protection. Into the people’s field of vision, LED light source lamp has become the world’s most new generation of energy-saving light source with the advantage of replacing the traditional light source. Therefore, LED high bay light will become the best choice for traditional large-scale industrial plant lighting lighting energy saving transformation, but also the trend of the times. .
1. The LED high bay lamp housing adopts high-strength die-casting or extruded aluminum materials, anti-aging electrostatic spray or oxidation treatment, self-cleaning and strong corrosion resistance.
2. Adopt high-quality CREE LED products, high stability, life expectancy 50,000 hours, more than 10 times longer than traditional light sources, to achieve low investment and high returns.
3, green pollution-free, cold light source design, no heat radiation, no harm to the eyes and skin. Contains no pollution elements such as lead and mercury, realizing a true green
4, user-friendly structure design, lighting installation and maintenance easier. Suitable for a variety of applications.
5, the lamp design is fully heat-dissipating, the surface cover has a lower temperature, safety, and good protection.
6, good color rendering, bright and stable, more realistic display of the color of the real, LED light source color temperature is optional, to meet the needs of different environments.
7. Meanwell power supply adopts constant current and constant voltage control, applicable to wide voltage (AC 90~264V/90~305V), overcomes the disadvantages of power grid and noise pollution caused by ballast, and avoids eye banding during work. Excitement and fatigue.
8, excellent decorative effect, the use of special surface treatment process, the appearance of color optional, simple installation, easy removal, wide application.
9. The difference between the actual consumed power and the rated power is not more than 10%, and the power factor is not less than 0.95.
10, LED high-bay light protection rating is not lower than IP65
11, the average lifespan LED high bay rated life expectancy of not less than 50000h.
12, the maximum temperature LED high ceiling lamp rated maximum temperature Tc value is not greater than 65 °C.
13, immunity, surge suppression performance (anti-lightning) voltage protection level should not be less than 2kV (line – line) and 4kV (line – ground).
14. Light Distribution Characteristics When the LED lamps in a lamp are extinguished or the entire lamp is dimmed, the spot shape and uniformity of the road illumination do not change significantly.
Heat dissipation technology: Pure aluminum alloy is used as the led radiator, which greatly reduces the operating temperature of the LED light source and ensures the stability and long life of the lamps. The temperature of the lamp body is guaranteed within 65 degrees Celsius.
US CREE company imported light source chip.
Taiwan imported power supply, power supply with UL, CE, TUV, RoSH, IP65 certification.
L90> 36,000 hours
Equivalent to the brightness of an ordinary 400W high pressure sodium lamp.
Lamp life up to 50,000 hours.
Ceiling-type, ceiling-mounted installation methods.
Good color rendering and various light colors are available to meet the needs of different environments.
The study of lighting ergonomics abroad has a relatively long history. The conclusion shows that the human eye’s perception and sensitivity of LED light effects are subtly different from traditional light sources. If you do not understand this difference, you may not be able to use the LED to bring us comfortable lighting. For example, what kind of light efficiency is more efficient? Why LED lighting has more glare?
First of all, from the human eye cells.
Human eyeballs add up to about 120 million cone and rod cells. Through rod cells, we can perceive light. Through cone cells, we can see colors.
The reason why cone cells can see the “color” is that they have three kinds of “green, red and blue” cells. With the RGB primary colors, we can see all the colors including white. However, there is only one kind of rod cells, so the color cannot be seen.
What needs to be corrected is that the so-called “red cones,” “green cones,” and “blue cones,” just mentioned, are inaccurate. The cells themselves do not have these colors, but they are just for red light. Green and blue light sensitive.
Red, green and blue are long wave, medium wave, and short wave, respectively, so they can be called L, M, S cells. For example, red sensitive cones, which can be called L-cones or long-wave cones, represent long wavelengths. Short-wave cone cells are blue light-sensitive cone cells, officially called S-cones. Green light-sensitive cone cells are called M-cones and represent medium-wave cone cells.
In addition, the degree of activity of cone cells and rod cells depends on the strength of light. If the illumination level is high, the cone cells work efficiently, and the rod cells are very inactive. When the illumination is very low and very dark, the cones are not active. Therefore, under very dark conditions, we use rod cells to observe and see only black and white and no other colors in the line of sight. We will have data later to illustrate this point.
Why LED lighting more easily glare?
One interesting point is that blue light-sensitive cone cells only exist in the peripheral area of the fovea, so it takes more attention to see the blue, which is why blue can attract more attention. . So the trademark with blue is a good choice.
But it also means a bad fact: Blu-ray produces more glare.
While driving, we usually look at the road ahead. The road lighting fixtures image the surrounding area of the eyeball. In the peripheral area of the eyeball, there are more blue-sensitive cells.
In the past, road lighting fixtures had only one large light source, a large light source with uniform brightness and glare, and the visual cells only needed to transmit an edge message to the brain. Now using LED light sources, assuming that the road lighting conditions remain the same, but there are many small light spots on the luminaires, with a lot of edge information, which may be the reason why LEDs produce more glare than traditional light sources.
In general, the typical brightness range of road lighting is between 0.3-3 cd/m2. The brightness greater than 3 cd/m2 is the brightness category of indoor lighting or natural light lighting.
From the figure we can see that cone cells are active under high brightness conditions, while the rod cells are basically inactive. Until the brightness dropped to about 5 cd/m2, as the brightness became darker, the activity of the cone cells gradually decreased, and the activity of the rod cells gradually increased.
In the middle area where both types of cells are active, we call it intermediate vision. The road lighting is in this visual range, when the cone cells are more active than rod cells, but both are working.
▲ The solid line represents the cone cell and the dotted line represents the rod cell
Note that in the above figure, the maximum sensitivity of the cone cell is in the yellow region of the visible light spectrum, while the punctuated cell represented by the dotted line is more sensitive and the peak is in the blue-green region. In contrast, cone cells are highly efficient for green, while rod cells are more efficient for blue light.
What is their efficiency in the middle vision?
The dotted line in the figure represents the change in the efficiency of the intermediate vision. It can be seen that the more neutral the light is, the higher the intermediate visual efficiency is. It was then suggested that the use of blue-rich light is more efficient and energy-efficient than warm white light!
From a theoretical point of view, this point of view is indeed feasible. The 2017CIE report also made this clear. Using blue and white light can save about 2%-8% of light. But in reality, this practice is not necessary and may even cause new problems.
First, for example, a brightness of 0.3 cd/m 2 , if blue-white lighting is used, the lighting level can be reduced by 8%, 0.3 cd/m 2 by 8%, and the brightness can be reduced to 0.28 cd/m 2 . If you use blue light for indoor lighting, you can save 2%. In a few cases where the lighting level is already low, you can save about 8%. However, whether it is road lighting or indoor lighting, this light is simply not worth mentioning. You can even ignore this point of view.
In addition, if blue-white light is used, it will cause more scattering in the eyeball and the atmosphere, resulting in more light pollution. (As we mentioned earlier, Blu-ray will make the glare more serious.)
And, in order to save the brightness that is not worth mentioning at all, there will be a very bad visual experience for the elderly. Here we will talk about the lighting needs of the elderly.
What kind of lighting is more friendly to older people?
As you age, the lens of your eyes turns yellow. The yellow light can easily pass through the yellow lens, and the yellowish green can also penetrate. Even the orange and reddish can easily penetrate the yellowed lens. However, in the spectrum, blue is far from yellow and blue cannot easily pass through the lens of the elderly. Therefore, if the use of blue and white light is only to save 2% of light, or 8% of light, it may not matter to young people, but it is for the elderly to suffer!
In addition, if you want to design excellent lighting for the elderly, you can’t simply increase the light, because it may produce more glare. Therefore, to be very careful design, you must understand a lot of knowledge in this area. For example, blue light is bad for the elderly, while yellow light and warm white light are more friendly.
Every thought, every evaluation, we just on fire to share.