1.Why we should use LED downlights ?

The first and most important thing is using a LED downlights can save your money! How it can save money? We are going to show you that below

LED downlights is more energy saving as the LED is using high-brightness white light-emitting diodes as the light source, using the cold light, no heat generation.

Let’s make a comparison as below:

An incandescent lamp of the same brightness needs 60W, and 1 kW can be used for 17 hours.

An energy-saving lamp needs 10W to achieve the same brightness, and 1kW is used for 100 hours.

One LED downlights only needs 3W, 1kW can use 333 hours.

So it’s obviously that using LED downlights can help you to be benefit by the lower power cost.

ALSO LED downlight with high light conversion rate: 90% of the energy of LED lamps is converted into light energy, while only 20% of halogen light bulbs are converted into light energy.

Environmental protection: I guest you don’t know that LED downlights do not contain substances harmful to the environment such as mercury (Hg)? And the assembled parts of the led downlight it can be easily disassembled , and can be recycled by others without recycling from the manufacturer.

Besides the above we also have more advantages of using LED down lights such as Protect eyesight, no shaking of light, fast response speed, completely eliminating the shortcomings of the traditional halogen startup process.

Now we will come out with next problem

2.Where we can use the led downlights?

LED downlights (sometimes known as recessed lights, pot lights or can lights) are widely used on both commercial or residential projects such as office,school, shopping mall, hospital, hotel and showroom etc.

 They are extremely versatile, and can be used practically anywhere.

3.What wattage downlights we should use?

The wattage of downlights was depend on how big is the area and how many downlights you are going to use. Also different area also require different brightness

Before the invention of the LED, people use wattage to measure the energy consumed by the light source and also the brightness. 

But for the LED downlight, it does not use the same method. As we know lumens are a measure of the total amount of light emitted by a light source. So lumens can be used to calculate power to measure the energy efficiency of LED chips. 

For example, a 7-watt LED downlight that produces 600 lumens has an 88% improvement in energy efficiency compared to a conventional downlight, which an conventional downlight requires 60 watts to produce the same brightness.

 Even for different LED lights, energy efficiency will be different, and lumens per watt can be used to calculate the energy efficiency of the product.

 From above, we are going to give you a simple standard as below: 

For instance, Suppose you are using a high quality LED light with high efficiency, you can consider each 3 suare meter use an 11~13W or 2 square meter use 5W~7W LED downlights for a shop area(not counter area). For more acurrate detail you can contact our staff for the further calculation. 

4.How to identify the good quality led down lights?

Before you buying a led down light you should consider the below 5 important things:

A, The LED chips

 The LED chip is a key component of the LED lamp, the electrical and optical properties of the LED lamp are determined by it. Because the LED chip is packaged inside, we generally can’t directly see it, so you need to keep your mind clear when you pick the LED chips.

In general, high quality LED chips can’t be very cheap. The price of the famous brand chips are quite transparent on the market. If the offer is particularly low, you should be careful that the seller is using the counterfeit goods or lower parameter item.

As a well experience LED manufacturers in China we suggest you to use the famous brand such as CREE, SHARP, EPISTAR, OSRAM LED chips to ensure the stable quality.

And you also have to be careful about the below points as there are some trap in it:

A.Use small size chips to replace the big chips.

Usually, the bigger chip, the stronger of withstand voltage and current resistance, but the cost is also higher. Small chips are generally poor in brightness.

Some bad suppliers use small IC to package the LED chips, but identifies a large forward current,( our design engineers often only use about 75% of the LED forward current to ensure the life of the led chips, minus the small light fades), so the brightness of the lamp chips look like the same or even higher than it shoule be, but it is actually sacrificing the life of the LED lamp chips.

B .Fake famous chips

Some packaged lighting factory consider the cost reason,they use Taiwan or China mainland chips pretending to be the LED light brand manufacturers such as CREE, Epistar, Osram’s chips. This is the common way for everyone to buy low-quality products with high price, which also may cause serious quality issue for LED down light products.

What’s the consequence when you use a low quality product? I believe everyone have known it and I will not go into details.

Furthermore, We will remind you that one of the most popular LED chips brands have many fake products, was CREE, because CREE technology is very mature, but the price is high, so they can have a lot of profit to pretend to be CREE chips.

 2.Heat sink

Let’s look at this first before we talk about heat sink.

LED light source illuminates electricity into light energy. However, electrical energy cannot be completely converted into light energy. Some of the energy is converted into heat energy, which causes the light source to be accompanied by heat during operation. The efficiency of electron-optical conversion is generally 20-30%, and the remaining 70-80% is converted into thermal energy.

Temperature vs life

Due to the heating of the LED, the LED lamp must have a heat sink, and the heat dissipation problem becomes an main parameter for evaluating the merits of the lamp. LED light decay, service life and junction temperature are inseparable, heat dissipation is not good, junction temperature is high, light decay is fast, and so life is shorter.

According to the Arrhenius rule, for every 10 °C drop in semiconductor devices, the lifetime will be doubled. From the light decay curve published by CREE, temperature is the main reason for the life of the lamp:

Curve of light decay and junction temperature 

The heat dissipation problem affects the application of the light source, so heat dissipation is a key issue that has to be considered.

The heat-dissipating material with small thermal resistance has better heat conduction effect. For better heat conduction, the heat dissipation of each layer must be optimal.

We are going to show you some sample for better understanding what is a good heat sink:
  • The below picture shows a more common heat dissipation problem diagram.

The heat distribution of the qualified heat dissipation components is uniform or symmetrical. This makes it not easy to cause the internal temperature of the light source to be inconsistent and prevent uneven light distribution.

Therefore, most of the light sources of the lamps are located at the center of the lamp. The thickness of the heat sink heat sink and the heat convection fins have a great influence on the heat dissipation efficiency.

For qualified lamps, the heat sink heat sink thickness should not be too thick or too thin, and the distance and thickness of the heat convection fins should not be too large or too Small.

  • Below picture showing that the same shape of the radiator, the right side of the heat dissipation is better than the left              

In LED luminaires, the heat sink occupies a large part of the cost of the luminaire. In order to save costs, some manufacturers shoddy the structure, materials and design of the radiator, resulting in serious quality problems of the lamps.

How to judge the heat dissipation of the lamp is good or not? The most authoritative way is to test the junction temperature using professional equipment.

However, such professional equipment you may don’t have on your hand, so the easier way is use the most traditional method to touch the light to sense the temperature.

Now we will ask, is the light fixture good whey you feel hot or not hot?

Hand touch heat sink is very hot, certainly not good

The hand touch heat sink is very hot, the heat dissipation system must be bad, or the heat dissipation capacity of the heat sink is insufficient, and the heat of the chip cannot be dissipated in time; or the effective heat dissipation area is insufficient, and there is a lack of structural design.

The hand touches the heat sink is not hot, maybe good maybe not good

The chip has not much heat, good conduction, sufficient heat dissipation, and low temperature. This is a good cooling system, the only “disadvantage” is a bit waste material

But there is another reason that casue it not hot: If there is impurities under the substrate, there is no good contact with the heat sink, the heat cannot be transmitted, and it is concentrated on the chip. It’s not hot outside, but the chip inside is already hot.

Here, we recommend a very easy to use method – “half-hour illumination method” to determine whether the heat is good.

As we said before, the general LED junction temperature rises and the luminous flux decreases. Then, as long as we measure the illuminance change of the luminaire in the same position, we can reverse the change of junction temperature.

If you want to know more detailed methods, please click on the detailed article below.

“Half-hour illumination method” to determine whether the heat dissipation is good

3, The driver

 The driver device is the power source of the LED chips.You can image the LED chips is just like an electronic device which need a good power supply. And the driver is that” power supply”. We will provide you some useful suggestions help you to choose the right driver to match your application requirements to the LED.

Different from other switching power supplies, LED drivers or LED power supplies require high reliability and safety in lighting applications. Its output characteristic curve can be well matched with the LED lamp bead illumination curve and has good adaptability.

The LED driver converts the AC input power (usually 110VAC and 230VAC) into a stable DC power to power the LED chips and extend the life of the chips.

Select driver

The type of driver selected for the lighting application will be based on several factors.

A.Regulations are important

Does the entire system need to operate within a certain harmonic current range? Does it need to meet the safety standards for lighting, or is ITE power sufficient?

It’s important to know if your design standards meet the requirements, including any requirements for power consumption when turning off the power.

Safety standard

There are various standards for lighting systems. Internationally, Part 1 of IEC 61347 covers the general safety requirements for luminaire control devices, and Section 13 (2) of Part 2 applies to LED module power supplies. The United States has UL8750, and Europe has EN61347, all of which are named in the IEC format.

B.Constant current driver or constant voltage driver?

All LED drivers can be divided into two basic types, constant voltage LED driver and constant current LED driver. But some manufacturers have also launch a combination of two modes of LED drive power.

If you want to know more about the constant voltage driver and constant current driver. Pls read the below article which explain it in detail.

The led driver type and what is constant current driver & constant voltage driver?

C. The related parameters you have to consider
  • Input Voltage Input voltage is indicated on each LED driven label. It is necessary to know the local rated grid voltage before using the LED driver. For example, the voltage in the United States is 120VAC, the voltage in Japan is 110VAC, and the voltage in Europe and China is around 230VAC
  • .Output Current  When using a constant current LED driver, pay attention to the drive current required for the LED bead you selected. The LED’s parameter manual usually gives the rated current value, and the unit should also be noted, 1A = 1000mA.
  • Output power  It is necessary to choose an LED driver that matches the power of the LED luminaire. The output power of the LED driver is preferably slightly larger than the rating of the LED luminaire. If the output power of the driver is exactly equal to the power required by the LED luminaire, then the LED driver will always operate at full load, which will greatly reduce the life of the LED driver. And the rated power of the LED luminaire is also an average value. The maximum and minimum power required for the multi-string LED lamp bead are inaccurate. Therefore, the output power of the LED driver can best cover the power requirements of all luminaires.
  • Output Voltage  This voltage is the DC output in volts (V). For constant voltage power supplies, be aware that the output voltage value needs to reach the rated voltage of your fixture. The common LED lights require voltage levels of 12V, 24V, and 36V.
  •  Lifetime  LED drive life is usually measured in thousands of hours. Also known as MTBF (Mean Time before Failure), it is the time that the drive runs until it fails. The use of LED drivers under rated parameters generally guarantees their longevity and reduces maintenance costs.
  •  IP rating What is the waterproof and dust proof rating of your LED driver? If the drive is working in a dusty environment, it is recommended to select an LED driver above IP65. If the requirements are more stringent, IP67 or IP68 or higher products are required, and outdoor LED drivers often need to use this level of products.  The numerical meaning of the IP level is as follows, the first number indicates the dustproof level, and the second number indicates the waterproof level.

4, Light distribution system

LED is a directional point source. How to creatively apply this feature of LED to make a comfortable light environment is the key point of LED light optical design technology.

The LED light source itself generally has a lens or a transmissive material for improving the light exiting efficiency, and at the same time satisfies the light distribution of about 120 degrees of light emission, which is generally called a primary optical design.However, in order to meet the various needs of indoor lighting, it is necessary to redistribute the light according to the needs.

5.dimmable or not dimmable downlight?

Dimming is absolutely a useful function which we strongly recommand. The only disadvantage is that the price is more expensive than non-dimming.

Let us show you why here:

(1) Dimming can make you feel confortable by use different brightness

(2)If the light changes slowly not suddently, the eyes are easier to adapt without harmness.

(3)The dynamic changes of lighting create different atmospheres.

(4) dimming can achieve maximum lighting energy saving and save cost.

(5) Forn newly installed lighting, considering the attenuation and maintenance factor, the initial lighting will usually far exceed the actual required illumination.

People don’t kown that the light pollution caused by excessively strong and flickering lighting has caused great damage to the human body. At this moment, if your light is dimmable you can control the new lighting brightness by that.

More over, LED dimming methods usually have the following types: Switch dimming, digital dimming, triac dimming, if you are interesting to know more about these dimming methods please visit the below article.

The different lighting dimming type and how to choose it?

6.How to choose the color temperature of led downlights?

Color temperature is a measure of color. This concept original is based on a fictitious black object that emits different colors of light when heated to different temperatures, and the objects appear in different colors. Just like heating an iron block, the iron block turns red first, then yellow, and finally turns white.

But we don’t need to dig into this concept but only need to know how related to the lighting area. 

Applied to the led downlighting, different color temperatures will give us different feelings. It is easy to find that going to different places will have different colors. There will also be different color temperatures in our environment, and it will also bring us a different mood.

 In a commercial place, customers should also be given different feelings according to their own services.

Some people would prefer to choose the brightest LED lighting fixtures when choosing LED fixtures, which may bring out the result which not we really wanted.

Below we list some appropriate color temperature in several places for your reference.

Factory workshop: For specially meticulous work, with a lot of work we advise to use 4500-5000K close to daylight. Others, the color temperature is higher, such as: 5000-5500K. For work that is easy get tired, we suggest use a color temperature close to the daylight.

Office, conference room: Generally 5000-5500K. The color temperature of the reception room is 4000-4500K, which is convenient for the customers and staff to interact and communicate smoothly.

Hospital: The ward of general mental illness should be based on high color temperature, such as: 5000-5500K. In wards, the color temperature of natural light is 4000-4500K. The clinic is preferably 5000-5500K which make the patient be quiet, trust with the doctor, and cooperate with the doctor’s examination and treatment.

Shopping mall: mainly 3500-4500K. Different areas should be equipped with different color temperature downlights. Because this color temperature is natural and lively can cause people’s desire to buy.

Food area: 3000-3500K. This color temperature can cause appetite and increasing food sales.

Household area: The color temperature is 5000-5500K. Most home appliances are light in color, people feel it clean, high-grade, bright line.

Children’s product area: Children usually lively and active, 2500-3000K color temperature is in line with the child’s psychological characteristics. Can quickly cause children’s desire to buy.

Daily necessities area: 4500-5000K. Most of the daily necessities purchased by women. They are more influenced by emotions and their purchasing often arise by chance.If the color temperature is too high, it will cause too much hesitation, and the color temperature is too low, also not conducive to the association of purchasing.

School: Classroom, library, and science lab are recommended at 4500-5000K. Reason: Schools need to be quiet, serious, and lively.

Students use more eyes and concentrate on energy. Too cool will make the students feeling of depression, which is not good for the cultivation of students’ creative ability. The school’s art classroom, liberal arts activity room: should be in the 3000K–4500K. Help to stimulate students’ initiative and foster creative thinking.

The above is the basic knowledge of some color temperature and we can’t show all the information here. Here we have to remind you that that when the color temperature is higher, the lumen of the fixture will be lower.

you can contact us to consult about what color temperature LED lighting should be buy before you make the purchase. We are happy to provide our help.

7.How to decide the beam angle of led downlights

When we choose LED DOWNLIGHTS, how do we choose the right beam angle according to the scene we will use?

First let’s explain what is the beam angle of the luminaires.

From the light of the luminaire, there is a range of places where the light shines.

From a physical view, there is an angle between light and a boundary that is completely no light. If the beam boundary is determined completely in terms of light and no light, this is very difficult to measure and observe.

Because of the difficult to measure, a rule is made to specify an edge, and the light outside the edge has been reduced to negligible or useless.

There are relevant standards in the world. But different regions are not unified.

The International Commission on Illumination (CIE Europe) stipulates that the light intensity reaches 50% of the normal light intensity, and the angle formed by the two sides is the beam angle.

The International Illumination Society (IES USA) stipulates that the light intensity reaches 10% of the normal light intensity, and the angle formed by the two sides is the beam angle.

The definition that YUFENG Lighting generally use is the definition of the (CIE Europe), which is based on 50%.

We now take the 10°, 24°, and 38°beam angle examples.

In the picture below, the three powers are exactly the same, except that the three light with different beam angles illuminate the wall surface, and the light distribution curves of the three beam angles are shown.

We can see that the 10°angle of the light has a small illumination scope, and the center light intensity is the largest, which can form a strong contrast on the illumination surface;

the 38° angle light has a large illumination scope, but the center light intensity is the smallest, The spot formed on the illuminated surface is softer;

the 24° angle is an effect between 10° and 38°.

So we can conclude that at the same power, the larger the beam angle, the smaller the center light intensity is, and the spot is softer, the smaller the beam angle is, the larger the center light intensity is, and the spot is stronger.

Let’s make another example as below picture

The 10°angle gives a strong visual impact with its strong contrast of light and dark, and it can catch people’s eyes in the first time, but we find that under the strong contrast of light and dark, we can’t see the details of the plaster statue. And because the beam angle is too small, the statue is not fully visible in front of us.

The beam angle of 20° is much better than the beam angle of 10°, and the texture of the gypsum and the expression of the statue are well displayed, and there is also a good visual impact between the three.

The 30° beam angle makes the statue softer and more delicate, and you can more easily observe the details of the statue, but because the beam angle is too large, the background wall and the statue are mixed together, compare to 10° and 20°it is difficult to draw attention when the beams are placed together.

However, this does not mean that the beam angle of 20° is the best beam angle of this LED downlight. It can only be explained that it is more suitable to choose the beam angle of 20° for illuminating this statue!

Therefore, we also need to consider the projection distance, angle, and ambient brightness,and then choose different light beam angle according to their demands.

If the ambient illumination is relatively high, a narrow beam spotlight with an angle of 10° may be required because the ambient light can compensate for the unexposed area of the statue, while a narrow beam spotlight with a beam angle of 10° is formed on the statue. The strong contrast between light and dark has a good visual impact.

If the installation distance is closer, then the beam angle of 30° should be chosen. At this time, the beam angle effect of 30° is similar to the 20° angle effect in the picture.

As the distance becomes shorter, the illumination range also becomes smaller, and the light intensity also increases. Similarly, if the projection distance becomes longer, a spotlight with a beam angle of 10° should be selected. Narrow beam spotlights are particularly suitable for illuminating wall columns.

Below is our downlight D0083-09 beam angle illustration.The IES file will be provided for your reference.

If you still have more queries for this beam angle issue you can contact our stuff for more professional consultant service.


8.How to install a led downlights?

The LED downlight from Yufeng lighting comes at a compete unit consisting of two parts: the downlight body and the driver box.

All we need to prepare for the installation are two tools. One is a ladder and the other is a saw.

Before you begin with the installation process, when working with the electrical components.

Make sure you trun off the power at the main breaker.

Double check and measure the size of the ceiling hole, be sure it is the correct size for the outside rim of the luminaire to cover the hole while still allowing the back of the luminaire to secure to the ceiling with the spring folding firmly.

  • Pull electrical wire and cut length needed.
  •  Locate the power supply leads from the driver box and connect to power source using.
  • Connect the black wire to the live wire,white wire to neutral wire and green/yellow wire to the ground wire.
  • Place the driver box through the cut out hole and lay it on the ceiling.
  • Pull the spring clips on the fixture up and through the cut out hole.
  • Place the light body in the hole, making sure the spring clips are holding securely.
  • Turn the power in the room back on and test the light can be used normally.

9. The most important 4 tips for LED downlights maintenance

First of all, proper installation of the downlight is a prerequisite for extending the life of the luminaire. If it is not installed correctly, the luminaires will easily break down, sometimes even exploding, which is very dangerous.

Specially for the installation of home and bathroom and kitchen fixtures you must be very careful.

1.When using LED downlights, try not to switch frequently. Although the number of LED downlights is about 18 times that of ordinary fluorescent lamps, too much frequency will still affect the life of electronic components inside the LEDs, then shorten the life of the lamps.

2.Do not change the structure of the LED downlights during cleaning and maintenance, and do not change the parts of the lamps. After maintenance, the lamps should be installed as they were.

3.If the downlight was cover with dust, it should not be washed with water. Generally, wipe them with a dry cloth with little water. Ater that try to dry them as much as possible. Do not wipe them with a damp cloth immediately after turning on the lights.

4. Pay attention that in addition to special LED downlights with IP rating, the normal LED downlight should be avoided in wet environments. The wet environment will affect the electronic components of the LED lamp driver.

10.Warranty from Yufeng lighting

YuFeng Lighting are committed to produce high quality products in factory price. Our strictly engineering and extensive testing drives us to achieve the highest possible standards. As a result of this, we are able to offer a three-year warranty from the date of purchase on all Yufeng lihgting products. You can contact our after-sales team for the service of quality assurance. Below is the detail for your reference.

A. Warranty period

  • 2 years for conventional products (Non-LED).
  • 3 years for the LED light source of CREE,OSRAM,SHARP or other branded LED chips and good quality driver.

B. Terms & conditions

  • The warranty period commences on the date of the delivery out of factory.
  • The warranty period is based on a burn time of a maximum of 4,000 hours per year. In the case of more than 4,000 hours per year, the warranty period is adjusted on a pro rato basis.
  • This warranty policy only applies if the products have been properly installedand are used in the operating conditions specified by yufeng lighting.
  • Normally the Purchaser is automatically entitled to this ‘standard warranty’. On request, an ‘extended warranty’ or a ‘customised project warranty’ can be agreed after the specific dicussion.
  • If YufengLighting is unable to replace the a defective product with the same it will use all reasonable endeavour to replace with an alternative of a similar specification. Due to changes in specification by LED component suppliers this is not always possible 

C. Additional conditions

  • The Products wasbought directly from Yufeng lighting factory.
  • The costs of labour for the installation/dismantling of the Products are not covered by the Warranty.

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