One of the biggest technical challenges of LED lighting fixtures currently is the issue of heat dissipation. Poor heat dissipation can cause the weakness of LED drivers and electrolytic capacitors which prevents lighting fixtures from further developing and resulting in early light decay. Only by quickly transmitting the heat out can reduce the luminaire temperature effectively, as well as protect the power supply from working in a prolonged high-temperature environment.

Many of us may notice that the so-called IP67 outdoor underground lights are with rainwater infiltrating into the fixture, even though they’re with IP test reports that prove they are waterproof and some of the lights are a good brand, there are still leaks. So why does water leakage occurs In IP67 underground lights? Before we give an answer, you have to understand what IP67 stands for.

In our basic understanding, the lights in the home are there to help us see things clearly. It’s something that we use daily without giving it much thought. But they’re just more than that! Good lighting can make a home more attractive and welcoming. It changes the mood, sets the ambiance, and adds character to the places like living and dining rooms or bathrooms and kitchens, particularly in open-concept spaces. Lighting choices can make or break a room’s design and mood. And if…

If your kitchen is only with the overhead lighting, the problem is there will be a shadow zone generated by the ceiling light. When you’re washing dishes in the sink or chopping vegetables on the tabletop, with your back to the light, you are operating in your own shadow zone. It’s no wonder that many people in the kitchen will accidentally cut their hands, as the workbench where you are chopping vegetables is completely covered by shadows. So, how to avoid this unpleasant experience and don’t let it happen again?

When it comes to LED tri-proof lights, we are all familiar with these luminaires. It’s waterproof, robust, and versatile. Thanks to their outstanding performance, the tri-proof lights have been widely used in many applications. To serve different purposes, there are lots of new designs of tri-proof lights in the market now, giving us more options to choose the best tri-proof lights for our projects. But when it comes to buying tri-proof lighting…

IP Rating - Complete Guide

What Is IP Rating? – Complete Guide

When installing lights in your garden, warehouse, and even kitchen, you want to know how waterproof your lighting is. Because this ensures that you can install and use your lighting fixtures safely in a specific area. The IP Rating (or “Ingress Protection”) tells you just that. It is the measure of how much the electrical is sealed and protected from the intrusion of liquid, but also solids like dust and dirt.

The Ingress Protection or IP Rating is an important consideration during the selection of LED lighting products for any projects. It reflects the suitability of the light fitting to specific environmental conditions in indoor and outdoor installations. The specifications for light fixtures often include a value for IP, but what IP grade you should choose? Or what IP level is the most suitable for your applications? This article will give you a complete guide of it.

What is IP Rating (or Ingress Protection)?

The IP Code (or International Protection Rating, sometimes 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 standard aims to provide users more detailed information than vague marketing terms such as waterproof.

*Explanation of the letters IP is given in IEC 60529 (Ed. 2.1), clause 4.1

The first digit refers to the level of protection a scale or indicator enclosure against access to hazardous parts (e.g., dust particles, electrical conductors, moving parts) and the ingress of solid foreign objects, while the second digit defines the level of protection against liquids. The larger each digit is, the greater the protection.

First Digit: Protection against solids

LevelObject size protected againstEffective against
0Not protectedNo protection against contact and ingress of objects
1>50mmAny large surface of the body, such as the back of the hand, but no protection against deliberate contact with a body part.
2>12.5mmFingers or similar objects.
3>2.5mmTools, thick wires, etc.
4>1mmMost wires, screws, etc.
5Dust ProtectedIngress of dust is not entirely prevented, but it must not enter in sufficient quantity to interfere with the satisfactory operation of the equipment; complete protection against contact.
6Dust TightNo ingress of dust; complete protection against contact.

Second Digit: Protection against liquids

LevelObject size protected againstEffective against
0Not protected
1Dripping waterDripping water (vertically falling drops) shall have no harmful effect.
2Dripping water when tilted up to 15°Vertically dripping water shall have no harmful effect when the enclosure is tilted at an angle up to 15° from its normal position.
3Spraying waterWater falling as a spray at any angle up to 60° from the vertical shall have no harmful effect.
4Splashing waterWater splashing against the enclosure from any direction shall have no harmful effect.
5Water jetsWater projected by a nozzle (6.3mm) against enclosure from any direction shall have no harmful effects.
6Powerful water jetsWater projected in powerful jets (12.5mm nozzle) against the enclosure from any direction shall have no harmful effects.
7Immersion up to 1mIngress of water in harmful quantity shall not be possible when the enclosure is immersed in water under defined conditions of pressure and time (up to 1 m of submersion).
8Immersion beyond 1mThe equipment is suitable for continuous immersion in water under conditions which shall be specified by the manufacturer. Normally, this will mean that the equipment is hermetically sealed. However, with certain types of equipment, it can mean that water can enter but only in such a manner that it produces no harmful effects.

What IP Rating Will You Need?

If you don’t anticipate a harsh environment that is extremely dusty or wet then a lower IP rating would suffice.

In places that will have a lot of dust, debris, or potential to be in contact with any solids or liquids, you’ll want to make sure that the IP ratings are high and that you have adequate water resistant or waterproof coatings on your LED lights.

Following are the most popular IP ratings for some of the fixtures, such as flood lights, tri-proof lights, street lights, and their meanings:

IP20 or IP40 for indoor applications:

This is for lights that are designed to go in an enclosed fixture.  An IP20 or IP40 light should never be outdoors unless the fixture is sealed. It is usually fine indoors unless it’s an area of high humidity or other harsh conditions. A lot of LED LightsLED track lights, LED Linear and other fixtures fall in this category. They are a great option for indoor use in basic environments.

IP54 Dustproof Rating:

LED lights with IP54 give complete dust protection. Whereas, for liquids, it gives protection against splashing water only. This will be common in basic led light bulbs and indoor fixtures.

IP65 Waterproof Rating:

Considered to be perfect for domestic and commercial use, IP65 rating gives complete protection against foreign bodies and water jets. Water disposed of by a nozzle of 6.3mm will have no damaging effect on LED lights. Anytime you are purchasing an outdoor fixture it should be IP65 rated. This includes fixtures like LED Flood Lights or LED Parking Lot Lights.

IP67 and IP68 Waterproof Rating:

LED lights with IP67 or IP68 ratings give complete protection against foreign objects (similar to IP64 and IP65). However, the difference lies in protection against liquids. LED lights with this rating are much more resistant to water as compared IP65. Water will have no effect on LED light even if it is immersed in water of the depth of 1m.

For outdoor applications, the most commonly used IP level of LED lights is IP65, as it provides maximum protection against solid particles and a good amount of resistance against liquid particles as well. They can be fit to use for both in domestic and commercial purposes. The popular light fixtures such as LED street lights, outdoor LED strip lights.

IP Rating Reference Chart

Below is an easy to follow reference chart to help you decide which IP rating you need or have:

IP Rating Chart Penglight


In addition to the above-mentioned IP ratings, there is also with another different kind of IP grade – IP69K.

What is IP69K?

The IP69K rating provides protection against ingress of dust and high temperature, high-pressure water – making products with this certification ideal for use in conditions where equipment must be carefully sanitized.

In industries such as food processing, where hygiene and cleanliness are paramount, equipment must be able to withstand rigorous high pressure, high temperature wash-down procedures.

In many industries, where dust and dirt can be an issue, it is important to ensure that dust cannot penetrate the casing of a product and cause it to fail.

The IP69K rating is the highest protection available.

What is IP69K?

What are the advantages of IP69K?

In environments that require heavy washdown, such as in the food processing industry, the combination of water, chemicals, high pressures, and temperatures can prove fatal for electronic circuits and instrumentation. The IP69K rating offers complete assurance that the piece of equipment that has undergone that tests is both durable and resistant and conforms to the highest protection rating on the scale.

How does a product achieve the IP69K rating?

Products bearing the IP69K rating undergo a challenging set of tests to ensure that they offer protection against penetration of high pressure, high-temperature water and dust. The popular fixtures with this character such as IP69K tri-proof light.

How is the water intrusion test performed?

The water intrusion tests themselves are done by placing the product on a turntable with a rotational speed of 5 ±1 revolutions per minute. The product is then sprayed at close range at a rate of approximately 4 gallons/16 liters per minute with the water pressure of between 1160-1450 psi, at a temperature of 176°F/80°C.

The nozzle from which the water is sprayed is held between 4 and 6 inches from the product, at a variety of angles. Following this rigorous testing procedure, the product is deemed as having successfully achieved the rating if it completely resists water ingress.


You may have heard of some people refer to LED Tubes as Type A, Type B or Type C tubes. What does that mean? And, if you’re considering upgrading your fluorescent tubes to LED tubes, or are simply thinking of replacing other LED tubes, you’ll first need to understand installation and operation of the three different types of LED tubes options: Type A LED tubes, Type B LED tubes, and Type C LED tubes.

So, what are the differences between UL Type A, B, and C tubes? why the operations and maintenance considerations should be taken in? and what kind of effect will it give to the installation cost and benefits of your projects? To get straight of it, first, let’s take an overview of the explanation issued by GE:

UL Types of LED Tubes: Type A, Type B, Type C And Type A+B

UL Types of LED Tubes: Type A, Type B, Type C, And Type A+B

As a rapidly growing lighting technology, LED linear tube options are raising questions throughout the industry — it’s important to know the options and which one will work best for you.

When considering LED Tube refits, it is important to understand the financial aspects as well as the installation, operations, and maintenance implications with three different options, which are UL Type A, UL Type B, and UL Type C.

Type A – Easiest Installation

LED Tube with Integrated Driver – Compatible and Operated on Existing LFL Ballast

Description: This UL Type A tube, is designed with an internal driver that allows the tube to operate directly from the existing linear fluorescent ballast. Most of these products are designed to work with T12, T8 and T5 ballasts.
Advantages: UL Type A offers the simplest installation process— retrofitting involves a simple swap of the existing LFL with a UL Type A LED tube. Unlike the other options, no electrical or structural modification of the existing LFL fixture is required.
Disadvantages: However, with these benefits come some limitations. The lifetime of a UL Type A solution is dependent not only on the design life of the LED tube but on the linear fluorescent ballast life, which could result in additional maintenance and costs within the lifetime of the product. Ballast compatibility will vary by manufacturer and must be checked before installation.

Additionally, a UL Type A tube sacrifices efficiency due to the additional power loss from the existing ballast and is limited in dimming and controllability.

Type B – Simplest Total System

Ballast Bypass LED Tube – Wired to Mains

Description: Like the UL Type A, this UL Type B tube operates with an internal driver. However, UL Type B’s internal driver is powered directly from the main voltage supplied to the existing LFL fixture, requiring several important and unique considerations. GE’s Type B system requires an in-line fuse. GE offers in-line fuse & socket kit, for ease of installation.

Advantages: UL Type B offers the simplest total system— retrofitting involves wiring directly to main voltage, bypassing the ballast which removes any compatibility issues, as well as eliminating maintenance costs associated with ballast replacements.

Disadvantages: Installation of a UL Type B involves electrical modification to the existing fixture in order to connect the tube to the power supply. The existing LFL and its corresponding ballast must be removed from the fixture. Sockets should be replaced. (GE requires replacing with unshunted sockets.)

UL Type B is more efficient than UL Type A, with no power loss as a result of removing the existing LFL ballast, but similarly lacks control capabilities.

It is important to note that the fixture’s incoming power wires are connected directly to the sockets, meaning installers are potentially exposed to the main’s voltage during installation. For replacement safety reasons, strict adherence to installation instructions is critical when rewiring existing fixtures and utilizing UL Type B tubes. Safe installation can be completed, but total installation time and cost will increase because of additional precautions required.

Type C – Best Performance

LED Tube with Remote Driver

Description: A UL Type C tube, offered among GE’s Refit Solutions as the LED Tube with remote driver, operates with a remote driver that powers the LED linear tube, rather than an integrated driver. Like UL Type B, UL Type C involves electrical modification to the existing fixture, but the low-voltage outputs of the driver are connected to the sockets instead of line voltage.

Advantages: Installation for UL Type C tubes involves removing existing tubes and ballasts, and it may involve replacement of existing sockets if damaged. The fixture input wires must be connected to the LED driver, and the driver’s low-voltage output wires must then be connected to the sockets before installing the new LED linear tubes. Once installed, this driver can power several LED tubes throughout the fixture.

The UL Type C offers excellent system efficacy, best system compatibility, and greatest overall performance. It can be integrated with robust dimming and control functionality, helping to offset moderate labor and installation costs with heightened efficiency well into the future.

UL Considerations

If retrofitting an existing fixture that is UL approved with a UL-approved LED tube, the fixture will remain UL approved. If retrofitting an existing fixture that is not UL approved with a UL-approved LED tube, the fixture with the LED tubes would need to be submitted to UL for approval if UL certification is necessary.

GE’s Refit Solutions will keep intact the existing fixture’s UL certification because Refit Solutions are certified by UL. GE customers must read the instructions provided with Refit Solutions prior to installation to understand the inherent risks involved in altering existing systems.

As a more controllable technology than LFL, LED lighting can be successfully integrated into facilities energy-efficiency planning. And with new LED tube options, the installation work can be done without as much hassle. GE’s Refit Solutions can provide efficient LED lighting anywhere fluorescent tubes currently exist.

So, which LED Tube option is the most cost effective and the best solution for your application? Review the table below to compare each solution.

Dollarizing Type A, B and C LED Tubes
UL TypeType A without Ballast Replacement*Type A with Ballast Replacement*Type CType B
Cost Per LED Tube$12.00$12.00$11.00$12.00
# of Tubes4444
Cost Per Driver/Ballast$11$18
Socket Kit w/Fuse
Total Fixture Retrofit Cost (4 Tubes)4 minutes10 minutes10 minutes15 minutes
Labor Cost ^ ($/hr$15.00$93.20$93.20$93.20
Total Fixtures Retrofits Cost (4 Tubes)$49.00$74.53$77.53$79.30
Key BenefitsPlug and Play: Fast and Easy refit with not wiringMinimizes compatibility issuesIncreased Efficiency Best Option for use with controlsFewer compatibility issues. Reduction of external components (driver/ballast)
Best ApplicationQuick re-lamps requiring no professional electricians and minimal investment. Ballast is less than 5 years old.Retrofits where time and simplicity are imperative. The existing ballast is older than 5 yearsRetrofits where future proofing and life-time cost and efficiencies are paramount. Applications with immediate and/or future need for controls.Retrofits using professional electricians with the ability to execute proper re-lamps in the future, ensuring only specified Type B lamps are used.
Calculations are for example only and are meant to be directionally accurate in comparing options, but are not absolute.
* Ballast replacement is recommended if the installed ballast is more than 5 years old.
^ Labor rates will vary, but less skill is required to simply replace lamps. Costs based on certified electrician estimated hourly chargesand minimum wage for Type A without ballast replacement (sources: and

As you can see, Type A without Ballast replacement offers an easy plug & play solution with the lowest initial cost. Type C has a higher upfront cost, but is the best future-proofing solution as it offers the ability to work with controls that are currently in place, or that are installed at a later time.

Type B is the simplest total system, eliminating compatibility issues, but also has the highest installation cost. To determine the best solution one must consider the initial installation cost, long term maintenance implications, intended application, and overall which benefits are most desired.

– Above Type A, Type B and Type C definitions of LED tubes are from GE, source:

4 different types of LED tubes


Besides the 3 types of LED tubes, Type A, Type B, and Type C, there is also a type of hybrid LED tubes which are developed as Type A and Type B, also known as Type A+B. A Hybrid LED tube is a combination of Type “A” and Type “B” tubes.

This is a tube that can (may) work with the existing fluorescent ballast or can operate without the ballast. This is an excellent choice for those installations that want to use the fast installation method using the ballasts but have a backup plan if the ballast is not compatible. Some of the more clever designs allow the tube to be both SEP or DEP.

Following is the designation from DLC:

Type A and Type B

Dual Mode Internal Driver (UL Type A and Type B):

U-bend, Four-foot or two-foot LED “tubes” designed to replace U-bend four-foot or two-foot fluorescent lamps, respectively. Products in this category have the ability to operate off the existing fluorescent ballast and also have the ability to operate off of line voltage if the troffer is rewired to bypass the ballast. These products connect to the troffer using standard pin-base connections to the lamp holders. Note that due to testing considerations, at this time only products that can operate off specific ballasts types are eligible.

These four types of LED tubes are with advantage as well as disadvantage respectively, choosing the right products for your projects can bring you significant results.

As always, feel free to reach out if you have questions or if we can help. You can also leave your comments below for further discussion!


There are a lot of important factors to look at when choosing the right LED light fixture. Lumens per watt, fixture type, driver performance, color temperatures are all super important. But how about light distribution? Light distribution is basically the projected pattern of light a fixture will disperse onto a surface.

The importance of choosing LED Panel Light

How to choose the best LED Panel Light? (Complete Guide)

LED Panel light now is booming in the market, it’s one of the best lighting options for indoor applications, considering its easy installation, modern design, and efficient light quality. Now almost every supplier producing led lights can also produce led panel lights, so how to choose the most suitable panel light for your requirements? This post will tell you the differences of the materials used in the panel and learn how it affects the quality and cost.

First, let’s take a look of the structure of panel light:

LED Panel Light Explosive View

LED Panel Light Structure

From the explosive photo you can see that panel lights are mainly consist of frame, LED, diffuser, LGP plate, LED driver and back plate. Now let’s go over these materials and see what are the differences when you choose a panel light.

Frames(aluminum heat sink)

There are mainly 3 moldings of frame for panel light.

1. Stamping aluminum

Stamping alu normally made by 1mm aluminum board, and then welded to assemble as a frame, apply wiredrawing surface treatment.

Advantage: from appearance, the joint area of heat sink can reach a seamless level, it’s more light, easy to install and low cost.

Disadvantage: heat sink made with stamping aluminum is easy to scratch hands. And, for 36w and other higher wattage panel lights, heat dissipation is very bad, the situation of LEDs burn out is very often.

Stamping Aluminum heat sink

LED Panel Light with stamping frame

2. Extruded aluminum

Panel light with extruded aluminum, mainly made by AL6063 and AL6061 material, the structural strength of AL6061 is stronger than AL6063, but appearance and surface treatment are not as good as AL6063, basically, the differences are tiny. Frame made by extruded aluminum is most common for LED panel light.

Advantage: heat dissipation is good, with exquisite appearance, diversified surface treatment, low tooling cost and easy to shape up. And the sizes can be custom made according to different applications, with good plasticity. All these features make it the most ideal model to make led panel light.

Disadvantage: cost is higher compared to stamping aluminum, and material is more heavy.

Extruded Aluminum heat sink for panel light

LED Panel Light with extruded frame

Although the extruded alu is the best material to make LED panel, in the market now there are many short-term-business-suppliers have eyes only on profit only, they use cheap, unqualified materials to produce panel light. Normally, the thickness of the frame has to be 2mm, only that it can reach good heat dissipation.

3. Die-casting aluminum

Die-casting aluminum is mostly applied to the panel lights with small sizes that diameter is under 300mm.

Advantage: integration, a truly seamless profile, with elegant outlook, good heat dissipation and cheap price.

Disadvantage, tooling cost is high, size is fixed that it’s unable to modify randomly in accordance with customer requirements and without plasticity.

Round and square panel light, smaller sizes

Round and square panel light


Type of diffuser: PC, PMMA, PS, PP

1. PC——Polycarbonate


LGP with protective films

protective films on LGP

  • with high Intensity and elastic coefficient, high impact strength, wide using temperature range.
  • high transparency and free chromaticity.
  • high grade of H.D.T.
  • good fatigue durability.
  • good weather resistance (weather resistance is the ability of a material, paint, film, or the like to withstand the effects of wind, rain, or sun and to retain its appearance and integrity).
  • odourless and harmless to people
  • shrinkage rate of shaping is low and with steady size stability.

In a word, PC is with the best stability, the fire-rated level is high and safety certification is better.

However, in terms of production and marketing, PC is more expensive and because of the big static electricity, it’s easy to absorb dust during assembling, it also has higher labor cost(PC diffuser is with protective films on both sides, takes more time and energy to get it off ). Also, the light transmission for PC is much lower, at around 86%.

2. PMMA — known as acrylic


  • PMMA is with excellent weather resistance, higher Surface Glossiness, and better high-temperature behavior
  • PMMA board have good printability and sprayabilit, it can make ideal surface decorative effect process with appropriate print technology
  • Flame resistance
  • PMMA is fragile, easy to break

The advantage of PMMA applied to LED Panel Light:

  • Economical, PMMA is easy to pre-forming and materials are inexpensive, which makes it very common earlier in the production of panel light.
  • Silk print effect is excellent if you need to print your own logo and lamp parameters, PMMA is preferred.
  • Super high light transmission, up to 90% or so, but it also brings some troubles. Due to the high light transmission, it’s difficult for a diffuser to cover dust and other small stuff, so sometimes it always has a light spot. Like PC, PMMA also has protective files on both sides, that it’s easy to absorb dust due to static electricity, so it requires a very strict production environment (need to be dust-free) to produce panel light.

When you buy a panel light from suppliers, you can evaluate from their workshop environment whether it passes dust-free standard. Penglight have strict procedures to follow when selecting a supplier, see how we do with our supply management

Panel Light Diffuser

LED Panel Light Diffuser

3. PS——polystyrene

PS is with excellent chemical stability, thermostability, Optical transmission characteristic, insulation characteristic and with minor moisture absorption tendency, it can be used in a moist environment and it’s with high radiation resistance. But it’s fragile, with low impact strength and bad weather resistance, it’s easy to turn yellow and get crisp. Heat resistance is also bad, distortion temperature is 70-90°, only available to use under 70°, cold resistance is also not good, the brittle temperature is -30°

Although there are so many defects for PS, when apply for indoor the room temperature is normally more than 0° and without solar radiation, PS can be a good material for panel light. Compared to PMMA, it’s with small static electricity makes it easier and convenient to arrange production. PS is cheap, easy for produce and incise, light transmission can up to 88%, All of these features make it the favorite materials for suppliers when it first launched to market.

4. PP——polypropylene

PP is mainly used as a low-cost product. People in the industry call it waste materials.


  • non-poisonous, odorless, it’s one of the lightest variety of all kinds of plastic.
  • tenacity and fatigue durability is as same as PC
  • high light transmission, close to PS, can also up to 88%
  • without films on the surface, easy to produce and assemble.
  • PP is with good heat resistance, melting point between 164~170℃. without the external forces, it has no deformation even in 150℃


  • When apply to low temperature, it’s easy to get crispy, not wear-resisting and ageing easily
  • high static electricity, get dusty on surface after longtime used.
  • soft, panel light of big sizes are very likely to sag naturally

LGP (light guide plate)

LGP is a kind of PMMA with high light transmission, its main processing methods include: silk print, laser engraving and injection moulding. The thickness of LGP has 8T, 6T, 4T and 3T, the thicker the LGP, the higher the luminous efficiency, price is higher as well.

different thickness of LGP

Three LGP Compare

1. Silk print

Silk print is a common processing method for producing LGP.

Advantage: good effect and high luminous efficiency.

Disadvantage: costly, easy to create poor products and it’s difficult to regulate printing ink.

2. Laser Engraving

Laser engraving is another common processing method for LGP, but the production process has reduced the printing ink.

Advantage: low labor cost and material cost, product consistency is good and less defective products.

Disadvantage: luminous efficiency is with 3%-10% lower compared to silk-screen, and it will have a Grid effect on LGP as a result of laser engraving, need frosty and high diffusivity diffuser to solve this problem.

3. Injection Moulding

Injection moulding is normally applied to small products.

Advantage: extremely low material cost, good product consistency, few poor products.

Disadvantage: poor luminous efficiency, only have 90% of silk print, no plasticity, high tooling cost.


Panel Light LED PCB

Panel Light LED PCB

Using what kinds of LEDs will have direct impact on the cost and optical parameter. If you don’t specified, normally the panel lights are with Sanan led chip, packing type is SMD2835, with  following  optical parameter:

  • CRI: RA>80
  • Color temp: 3000K/4000K/5000K/6000K
  • SDCM: <6
  • Luminous efficiency: 100lm/w to 120lm/w

These are the most common configuration, matured and cost-effective. and for the PCBs are mostly fiber glass not aluminum. For some special requirements that need CRI>90 or SDCM<6 or need color temp at 2700K, this can also be achieved by changing a different LED chip, but price will be more expensive.

LED Driver

Driver plays a crucial role in the lifespan of led lighting, it’s very important that a driver is selected that is matched to the lamp and to be illuminated.

When selecting an LED driver, the following are five factors that you should take into consideration and determine which one is the best fit for your application:

  1. Total LED power per function: this is the key to determining LED driver topology.
  2. The ambient temperature of the electronic components: For example, with rear lighting where brighter LEDs are required, a linear driver is not the best option because of its high power dissipation; instead, a switching driver is a better choice because it is more efficient and, hence, runs cooler at higher power levels.
  3. Flexibility to change LED configurations: light adjustment capabilities by using multiple luminance methods such as voltage reference control and PWM control. A wide operating supply range allows configuration of power supply and the number of LEDs to drive.
  4. Supported features: such as auto dimming, individual LED control, color change.
  5. Supported diagnostics and safety compliance: such as thermal warning, thermal shutdown, open circuit, short, over-current protection, single LED failures, under voltage and overvoltage on the booster, LED temperature monitoring.

Now many suppliers offer their panel light with a branded driver, such as Meanwell, Inventronics, Lifud, etc, quality is guaranteed and with competitive price.

LIfud and Meanwell drivers

LED drivers

Back Plate

Back plates are for sealing and assist heat dissipation. Normally 1mm thickness back plate made by aluminum is better for heat dissipation and make entire structure stronger, but now in the market the back plate are mostly with 0.8mm thickness and some factories produce back plate with metal to further reduce material cost. Metal back plate can be rusted after long time used and have big impact on service life.


So, now you have a pretty good idea of what you need to look for in selecting a LED panel light that is sufficient enough for your application. I know it will be a lot to digest for you, especially if you’re new in this field. But don’t worry, just leave your comments or questions below, or you can contact us directly at, we will get in touch with you and reply your questions anytime.


LM80, LM79, L70 and TM21, what are the differences for lighting?

LM80, LM79, L70, and TM21, what are the differences for lighting?

We have got these questions a lot from our customers regularly, and it’s easy to confuse LM80, LM79, and L70 or assume they test the same measure in an LED product. Although all of them are used when discussing LEDs, they are not related measurements.

Understanding LM-79, LM-80, L70 can help you evaluate LED products. Learn why LM-80 matters and how the data can be used to improve your bottom line. So what are the differences between them?  This post will give you a detailed explanation.

What is LM80?

What is LM-80?

LM-80 is a method for measuring lumen depreciation

LM-80 refers to a method for measuring the lumen depreciation of solid‐state light sources, such as LED packages, modules, and arrays. Before the advent of LM-80, LED component manufacturers each reported lumen maintenance data using their own disparate and varied systems.

To avoid customer confusion, members of the Illuminating Engineering Society (IES), came together to create a standard methodology that would allow customers to evaluate and compare the lumen maintenance of LED components from different companies. LM-80 was born.

  • It was developed by the Illuminating Engineering Society of North America (IESNA), to allow people the ability to evaluate and compare the lumen maintenance of LED components from different companies.
  • It is typically a 6000hr test (can be 10,000hrs) that shows depreciation and chromaticity shift over the period at particular operating temperatures 55 degrees, 85 degrees, and a third manufacturer defined temperature, say 105 degrees.

Who can perform testing?

LM-80 testing should be performed by EPA recognized Laboratories. Only reports from recognized laboratories are relevant. This standard is used for the Department Of Energy (DOE) ENERGY STAR program early qualification in conjunction with other reports.

What does it provide?

The testing report issued according to a standard format will provide luminous flux for a given current over a 6,000 hours period with interval measurements. Luminous flux will be measured for 3 different LED case temperatures: 55ºC, 85ºC and a third temperature to be selected by the manufacturer. Besides, the lumen maintenance, the chromaticity shifts over the measured period.

Typically, LED chips are tested for 6,000 hours and extrapolated until they reach L70. LM-80 determines the rated life of the LED module, but not the life of the complete LED product. Other components, such as drivers, electrical connections, product integrity, etc. may fail before the LEDs.

What is LM79?

It is the Illuminating Engineering Society of North America (IESNA) approved method for the Electrical and Photometric Measurements of Solid-State Lighting. It measures an LED luminaire or integral lamp as a whole system according to a standard process using specified equipment.

IES and Integrating Sphere Testing facilities

IES and Integrating Sphere Testing facilities

Who can perform testing?

LM-79-08 testing should be performed by EPA-Recognized Laboratories for the category of the product tested. Only reports from recognized laboratories are relevant. This standard is used for the Department Of Energy (DOE) ENERGY STAR program qualification and lighting facts advocate program.

What does it provide?

The testing report issued according to a standard format will provide:

  • Total Luminous Flux (light output)
  • Luminous Intensity Distribution
  • Electrical Power Characteristics (wattage, voltage…)
  • Luminous Efficacy (calculated)
  • Color Characteristics (CRI, CCT…)

While LM79 measures several aspects of a complete fixture, LM-80 solely measures the lumen depreciation of the LED module.

What is TM-21?

It is the Illuminating Engineering Society of North America (IESNA) approved method for taking LM-80 data and making useful LED lifetime projections. The standards apply to lifetime projection of LED package, array or module alone. The results can then be used to interpolate the lifetime of an LED source within a system (luminaire or integrated lamp) using the in-situ LED source case temperature.

TM-21 calculator

TM-21 report

Who can perform testing?

There is not such a thing as testing, it is a mathematical method based on LM-80-08 collected data.
Among other things, TM-21-11 will consider:

  • If total LM-80 data period is  between 6,000 and 10,000 hrs, we consider the last 5,000 hours
  • If the total data period is above 10,000 hours, we use the last half of the collected data
  • In situ case temperature interpolation using Arrhenius equation between LM-80 temperature
  • Projections are limited to 6 times the available LM-80 data period so projected and reported lifetime may or not be the same

For example, Philips Lumileds tests several of its popular LUXEON products for 10,000 hours or longer, so that our customers can claim a 60,000-hour-or-more lifetime for their products.

What does it provide?

The method will provide a projected lifetime for the LED source or system. Life notation results will then use the following standardized nomenclature: Lp (Yk)

  • P: Lumen maintenance percentage. For LED luminaire we consider L70 to be the standard. After 30% lumen depreciation, we consider the system is not performing its duty anymore and should be replaced.
  •  Y: Length of LM-80 data period in thousands of hours
    Example: L70(6k) = 36,000 hours

What is L70?

“My LED’s will last for 50,000 hours.” “My LED’s will last for 100,000 hours.” We have all heard these claims. The truth is that an LED being an electronic device with no moving parts could theoretically last forever.

Three things can kill a LED. Heat, dirty power and moisture will all have detrimental effects on LED life. In reality, even if LED’s could last forever, their lumen output will diminish over time to a point where they would no longer function as a useful lighting source. We call this “lumen maintenance.” The industry has determined that the LED ceases to be a useful light source when lumen output reduces to 70% of its initial lumens. This is called L70.

L70 is a lifetime measurement criteria developed by IESNA (Illuminating Engineering Society of North America) to evaluate the useful lifetime of an LED luminaire in terms of the expected number of operating hours until the light output has diminished to 70% of initial levels. or when the lumen output is 70% of its initial output.

As LEDs do not fail and “burn out” like other light sources; instead, they gradually decrease over time until they are no longer producing useful light. It is generally established that the human eye is only sensitive to lumen depreciation of 30% or more. Therefore, L70 lifetime is defined by Illuminating Engineering Society Standard LM-80-08, entitled “IES Approved Method for Measuring Lumen Maintenance of LED Light Sources.

L70 lifetime is dependent upon many variables, such as the operating temperature, drive current, and the technology and materials used to construct the products.

L70 Lumen Maintenance

L70 Lifetime


Now you get the hang of what are LM80, LM79, L70, and TM-21, and what are differences between them, but if you still have questions, just leave your comments below, we will answer any of your questions and guide you through.

Penglight sources lighting products only from recognized suppliers that are able to offer full reports for their products, if you’re looking for a professional LED sourcing agent, feel free to get in touch with us.