LED strip light buying guide: How to choose LED strip lights

This is an all-inclusive purchase guide for LED strip lights. It explains in details the nine major factors to consider before choosing LED strip lights. With so many options on the market, it is really hard to tell which one is good. We have prepared this article to educate new and experienced users. It has greatly helped buyers to determine the right LED strips for a lot of projects.

1. Need single white or tunable white light? Select the white color temperature you need.

If you need install white lights, the color temperature of white lights should be carefully considered.

• 1800K is the orange color. It is unique and very impressive, super warm with reddish and yellowish tone.
• 2400K is the amber color. It is very warm lighting with yellowish tone.
• 2700K is similar to light color that incandescent lamps generate. It is a warm and relaxing lighting.
• 3000K looks like the light of halogen lamps. It is slightly brighter than 2700K, and puts a slightly yellowish or reddish tone on objects illuminated.
• 4000K or 5000K, also known as neutral white, is a whiter white than 2700K or 3000K. It is commonly used in office and commercial lighting.
• 6500K, also called cool white or daylight bright, is the brightest pure white. It mimics the natural sunlight of a sunny day. School, work and production environment widely utilize 6500K strip lights to increase productivity. 6500K light is an essential element for high end modern hotels, restaurants and clubs.

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2700K vs 3000K

Tunable white LED strip lights, also called white adjustable, can produce lights with color temperatures from 1800K to 6500K, or from 2700K to 6500K. They are made by using both warm white and cool white LEDs on the same FPC board. The lights of warm white and cool white LEDs are mixed to various levels of relative brightness to produce light of varied color temperatures.

2. Prefer color changing light? Consider RGB, RGBW, or RGBCCT.

If you like colorful light, you can choose RGB LED strips, or RGBW and RGBCCT. They all have colorful light. The difference is that RGBW or RGBCCT has pure white light, but RGB doesn't.

RGBW LED strips have white light of single color temperature, which can select only one from 2400K, 2700K, 3000K, 4000K, 5000K, or 6500K. It is worth mentioning that we offer super high brightness version, which has three rows of high density LEDs with RGB in the middles, white on each side. It is suitable for almost anywhere, because if it is too bright, you can dim down anyway. But if you use a lower brightness LED strip, you can not bring up the brightness higher than its designed limit.

RGBCCT Tunable White LED strips have all the colors, and various adjustable whites at the same time from one single strip! That means you can enjoy not only millions of colorful light, but also and all the whites mentioned above.

3. Indoor or outdoor waterproof.

For indoor applications, please choose IP20 indoor LED strips. Choose outdoor waterproof LED strips, IP65 or above, for outdoor or semi-outdoor applications. Waterproof ones are also good for indoor use, as their outside layer of waterproof tubing can protect electrical parts from dust and impact.

4. Voltage: 12V or 24V DC.

Compared to 12V, what advantages do 24V LED strip lights have? 24V lights operate with half current as 12V ones, which is determined by the relationship of power, current, and voltage.

If a lighting project needs continuous and long run installation of LED strips, 24V version is better. The reason is a commonly known issue "voltage drop". Voltage drop is the phenomenon that electrical voltage decreases along the road because the electrical resistance is inevitable along the circuit.

Due to voltage drop, the light at the beginning part of a long LED light strip will be brighter than that at the end. The voltage drop is smaller for a 24V LED strip than 12V. Many 24V LED strips can run continuously up to 10 meters (about 32 feet) without noticeable brightness decrease from end to end.

Current Controlled LED strip lights can resolve the voltage drop issue, to certain degree. But they are more expensive, because they have more complicated electrical circuit design, utilize more electrical parts, and need longer time for manufacturing.

Most cars, RVs, boats and yachts have 12V power system on board. So, 12V LED lights are the only choice.

5. Brightness.

Light creates atmosphere via its brightness and color. In light science, brightness is measured by using lumen. It is indicated in the value of lumens.

What is lumen?
Lumen. Lumen is the measure unit for the total quality of visible light emitted during a unit of time. It indicates the brightness level of the light produced by the light source. Traditionally, electricians use foot-candle as the measure to tell the light intensity, as is the customary unit used in the United States. A foot-candle equals one lumen per square foot. The brightness level roughly equals to the light that is one foot away from a common wax candle.

If you need brighter LED strip, you will select those marked with higher value of lumens per unit length. Please be careful that different manufacturers may use different brightness marks.

For example, one strip is marked as "240 lumens/ft", another marked as "700 lumens/meter". We cannot say that the second one is brighter than the first, because the length units are different.

Unit conversion is necessary for meaningful comparison. Say we convert the brightness mark of the first strip to lumens/meter. 1 meter equals 3.28 feet. The first LED strip would be 240 lumens/ft*3.28 = 787.2 lumens/meter. Now we find out that actually the first one is brighter than the second.

Luminous efficacy. Luminous efficacy is another important factor regarding brightness. It is the ratio of the light strip's lumen value to its wattage. By this definition, we can see that the ratio measures the efficacy of emitting light when using one watt of power.

When consuming the same amount of power, a light strip with higher luminous efficacy can produce more lumens of light. To put it from another perspective, when generating the same brightness, higher luminous efficacy means less energy consumption, saving more on operation cost.

Relationship between brightness and wattage. The brightness of a strip light is correlated to its wattage, the power it consumes. Similar to light bulbs, the higher wattage a light is, the brighter it is.

How many lumens do I need for a space?
When installing LED strip lights for homes, we often encounter the questions: how many lumens do I need for the space? How many lumens per square foot should be planned to illuminate the rooms optimally and comfortably?

To achieve optimal brightness for different rooms, you can refer to the following table as a general guidance:

6. The number of LEDs, LED density, and LED types.

LED density: the meaning of the number of LEDs on a unit length

The number of the LEDs has meaning only when it is viewed by the length of the strip, e.g., how many LEDs per meter or per foot. It is commonly referred to as the LED density.

LED Density indicates how far away one LED is from the next, indicated by the LED quantity per meter or per foot, such as 60 LEDs/meter, 120 LEDs/meter, 18 LEDs/foot, or 36 LEDs/foot.

How does LED density affect the brightness?

In general, all other factors comparable, a higher density LED strip is brighter than a lower density one. This is because there are more LEDs emitting light on the higher density ones. By comparable factors we mean the same type of LEDs, the same current drawn, etc.

Light spotting: How does LED density affect light distribution?

A common phenomenon of LED strip lighting is that for certain projects, you can clearly see the light spots or LED dots on the diffuser of a light strip fixture. This is so called "light spotting" in light distribution. Perfect distribution would mean no light spotting.

Light spotting is affected by two factors: the distance between LED and diffuser, and the distance between two adjacent LEDs.

Distance between LED and diffuser.
How the distance between LED and diffuser affects light spotting can be understood this way. If you stand 10 meters away from a wall and project a flashlight onto the wall, you'll see the whole wall area is lighted, we consider the light distribution good.

As you move closer to the wall, the lighted area becomes smaller and smaller till the point it reaches to the same size of the flashlight head. At this time the light distribution is not good because of the light spotting is very pronounced. This character is universal to a spot source of light.

Same as the flashlight, LED is a spot source of light. So if the light spotting is an issue, we can choose to increase the distance between LED and diffuser. If we are using LED strip channel assisting installation, we can choose deeper channels so that the distance between LEDs and the diffuser is larger.

Distance between two adjacent LEDs.
In contrast, the shorter the distance between two adjacent LEDs is, the higher the LED density, the better the light distribution of the LED strip. It is because the shorter the distance is, the easier for the LEDs to cover each other's blind spots.

There is a situation when the distance between LED and diffuser can't be longer any more due to limitation on installation space. In this situation, in order to obtain less light spotting or better light distribution, light strips with higher LED density are the right choice.

Some of our LED strip lights are specially designed to achieve perfect light distribution. They come with high density of LEDs. Even used in shallow aluminum channel, they present very nice light distribution with no light spotting. At the same time the light strip produces high brightness with low current drawn, generates little heat, and promotes long lifespan.

LED types.
The type of SMD LED package is often indicated by a number, such as 2216, 2835, and 5050. The number is actually the LED package's dimensions in size

• 2216: The size of a 2216 LED is 2.2mm x 1.6mm, height is 0.6mm. 2216 LED has the smallest and ultra slim body, perfect to make high density LED strips, such as tunable white, to get the best mixing effects for tunable white color temperatures. It is also the best LEDs to make ultra slim light strips to fit small grooves. Each LED usually has the power of 0.06W, 0.15W, or 0.2W.


• 2835: The size of a 2835 LED is 2.8mm x 3.5mm, height is 0.7mm. Each LED usually has the power of 0.1W, 0.2W, or 0.5W. It is one of major LEDs to make white LED strip lights. It is also used to make colored light.


• 5050 RGB: The size of a 5050 RGB LED is 5.0mm x 5.0mm, height is 1.6mm. Each LED has three chips inside, red, green and blue. It is the major LEDs to make RGB LED strip lights. Each LED usually has the power of 0.2W.


• 5050 RGB+White: It is also known as RGBW. The size of a 5050 RGBW LED is also 5.0mm x 5.0mm, height is 1.6mm. Each LED has four chips inside. In addition to red, green and blue, it has the fourth white chip. Due to this, it is also called 4-in-1 LEDs. The white chip is able to produce pure white light. The 4-in-1 design makes this LED the best to make RGBW LED strip light. Because the white chip is so close the colored chips, this 4-in-1 RGBW LED produces the best light mixing distribution when blending white into colored light.


• 5050 RGB+Tunable White: It is also known as RGBCCT. It is the same size as RGBW LEDs. In addition to the three colored chips, it has two more white chips: one is warm white, one is cool white. In this sense, it is also called 5-in-1 LEDs. The two white chips can produce tunable white. Because the white chips are very close to the colored chips, the 5-in-1 RGBCCT LED is the best LED to make RGB Tunable white LED strip light. It has much better white and colored light mixing effect than other types of RGB Tunable white LED strips.

In summary, the size of 2216 LED makes it perfect to make tunable white LED strip lights. 2835 LED has bigger heat dissipation base and lower height, and is perfect to be used to make white led strips. 5050 LED has bigger light emitting surface and multiple chips inside, and is widely used to make white and colored strip lights.

2216 LED has the smallest and ultra slim body, perfect for high density LED strips, such as tunable white. It is also the best LEDs to make ultra slim light strips to fit small grooves.

7. Color rendering index (CRI).

Recommended Reading High CRI LED strip lights

CRI is the measure that indicates the light source's ability to render the original colors of objects lighted by the light source. The original color is defined by the color when the object is illuminated by sunlight.

The closer the color of an object rendered by a light source is to the color of the same object under sunlight, the higher CRI the light source has. CRI has a value range running from 0 to 100. By definition, sunlight has the perfect CRI with the value 100.

Note: The higher the CRI value is, the better the quality of a light source in the sense of its ability to render colors. This is important to lighting applications where color matters.

For example, we take a look at the produce area where a supermarket sells vegetables and fruits. When high CRI light is used, the produces appear in natural and saturated colors, looking juicy, glossy and fresher. Hence, they are apparently more attractive to customers.

Same with fresh meat. Under light of high CRI, the meat is in purple red that looks fresher. If CRI is lower than 80, the colors of the object illuminated are distorted in such way as if they were covered with a gray veil. The object looks gloss-lacking and dull.

From the perspective of protecting vision of human eyes, light strip intended to be used long time need to have CRI higher than 80. Light with CRI lower than 80 will affect human eyes' ability to differentiate colors. Long time exposure to light with CRI lower than 80 may cause various vision problems.

All our LED strip lights have CRI 85+. For your professional needs, we also carry high CRI 97+.

8. Length and width.

The length is usually 5 meters(16.4 feet), or 10 meters(32.8 feet). Why they are made into 5M or 10M long? It is because of the voltage drop along the strip. For a 12V LED strip, if it is longer than 5M or 16.4FT, the LEDs at end will look noticeably lower in brightness.

When purchasing LED strips, pay attention to the length noted by sellers or manufacturers. There are ones in 2 meter or 3 meter long. Be aware that with the money you paid, how long the light strip you are getting.

The width varies from 5 mm, 8 mm, 10 mm, 12 mm to 20 mm or more. The 5 mm ultra slim version is designed to meet the needs of special lighting projects.

Note: If you use LED strip channel, need to consider if the inner width matches the light. Also if you used LED solderless connectors, the connectors are usually wider than the LED strip. Need to check if the connector's width fits the inner of the aluminum channel.

9. Choose LED strip power supply.

Should I choose power adapter or switch power supply?

1. Power adapter is easier to install. What you need to do is just plug the power adapter into LED light strip. Usually a power adapter can power one to two strips, fit for small installation.

2. Quality power adapters are UL listed. Make sure you are buying power adapters with real UL certificate.

3. For medium to large installation, choose professional brand name power supply. LED Power supplies usually can provide power for many strips.

4. Quality power supplies and power adapters can provide full indicated amperage for continuous operation. Inferior power supplies provide less amperage than indicated. When put into continuous operation, inferior power supplies will become too hot, and usually fail in short time.

6. Voltage and Wattage of LED strip power supplies

• Voltage. LED power supplies should provide proper voltage for light strips. 12V and 24V LED strips should use 12V and 24 power supplies respectively.


• Wattage. Power supply should be able to provide enough power for the lights. The power or wattage needed is determined by the wattage of the light strip to be installed. Wattage calculation formula: Wattage= Length x wattage/meter. For example, if you are installing a 3.5 m light strip with 16 W/m output, the total wattage is 3.5 m x 16 W/m = 56 W.


• Then we calculate the wattage of power supply needed. Rule is that power supply should not be used to its full capacity, because full load will cause too much heat and shorter lifetime for the power supply. 20% more capacity is recommended.
  
  For example, for above installation, the power supply should be: (1+20%) x 56W = 67.2W. There is no such a power supply with this exact wattage on the market. We choose the next level of output, which is 72W. A power supply with higher than necessary output won't harm the strip lights. It will provide only necessary output needed.