Because LED light source can save cost and energy, so LED street lights in recent years the development is very rapid, many cities will be newly installed street lights or traditional street lights are converted to energy-saving LED light source street lights.

However, the American Medical Association (American Medical Association, AMA) in 2016 has issued an official statement warning that if the LED street light is too white and too bright, the LED light source will release a large amount of blue light, not only may be driving due to the glare and increase the chance of car accidents, if the installation in the community, the public or wildlife exposed to it, will also have an impact on the sleep cycle. cycle. It also affects your health.

Let's take a look at the following comparison chart after replacing the light source with LED light source

The yellow light on the left is the traditional street light, and the white light on the right is the retrofitted LED street light.

Why some street lights are yellow light, some street lights are white light?

In fact, this is caused by the color temperature of the LED light source, this article, we will explore the color temperature of the LED as well as according to different use scenarios to recommend the appropriate color temperature.

What is LED Color Temperature?

Color Temperature Definition

Let's take a look at Wikipedia is so defined, Color temperature is a parameter describing the color of a visible light source by comparing it to the color of light emitted by an idealized opaque, non-reflective body.

Color temperature is usually measured in kelvins. The color temperature scale describes only the color of light emitted by a light source, which may actually be at a different (and often much lower) temperature.

LED Color Temperature Chart

The color temperatures of our common light sources are: 3000K, 4000K, 5000K, 6000K, etc.

3000K LED bulb light is yellow, the color is relatively soft.

4000K to 5000K, this range of color temperature is closer to sunlight, is a clearer white light.

However, 6000K LED bulbs emit a very bright white light with blue light, and the quality of the light begins to deteriorate and may feel too harsh. As the color temperature rises, the color of light emitted by the LED bulb is slowly converted from yellow to blue-white.

The chart below gives a better idea of the color of light emitted by each color temperature range.

 

How to choose the right color temperature?

LED street light color temperature selection needs to consider a variety of factors, the following we will do a brief analysis from the comfort, pedestrian safety, the use of the scene, and geographic latitude and other aspects.

Comfort

The eyes of human beings or small animals perceive different colors of light sources differently. For example, warm color light (3000K) will always make people feel comfortable, cozy and relax. And cold color light (6500K) sometimes makes people feel harsh and unnatural. So the color temperature of road lighting should be selected with visual comfort in mind.

Pedestrian safety

The main role of road lighting is to provide safe lighting for pedestrians and vehicles passing by.

Low color temperature, such as 3000K, may not be able to clearly identify the surrounding environment of the object color, of course, this also includes vehicle color and pedestrian.

However, high color temperature, above 6000K, in winter snow or rainy days, the reflection of snow or water on the ground into blue and purple, affecting the visual judgment of pedestrians or drivers, which may cause traffic accidents.

Usage Scene

Different installation scenarios, the color temperature of the light source has different requirements.

In residential areas, we have to consider the impact of the color temperature on the sleep quality of humans and small animals at night. If the color temperature is too high, it will seriously reduce the sleep time and affect the health, so the color temperature of 3000K is the most ideal lighting color temperature for humans and small animals.

If in the industrial area, a high color temperature, high brightness street lamp is very necessary. It can reduce safety accidents.

Geographical latitude

If you live in high latitudes, people prefer warm color temperatures due to the cold climate.

In low latitudes, near the equator, people will be more eager for coolness due to high temperatures, so high color temperature lamps are more suitable for this area. Low color temperature lamps may depress and annoy people.

So it is very important to choose a lamp with the right color temperature, if you are a novice in this area, we can recommend lamps with the right color temperature for you to choose according to different use scenarios.

Outdoor Lamps CCT Recommendation

According to the International Commission on Illumination (CIE), the average color rendering index (CRI) measures the color reproduction of LED bulbs, which is also a way to verify the color temperature of LED street lights. Typically, LED bulbs with a CRI greater than 80 are more visually appealing. A general street light with a CRI greater than 70 is sufficient.

Residential Areas:

LED street lights with a color temperature of 3000-4000K are usually used in residential areas to help people and small animals sleep well, too high a color temperature will reduce sleep time and affect sleep quality.

Parking Lot:

4000K is recommended to clearly distinguish the color of vehicles and pedestrians.

General Road:

4000-5000K LED street light is suitable for general road area. Color temperature is too high, will produce blue light, to the driver caused by glare, visual fatigue, affecting driving safety

Industrial and Commercial Places:

It is recommended that the color temperature of 5000K or more LED street lights

High latitude Areas:

3000K-4000K, giving people a warm feeling

Low latitude high temperature area: 5000K-6000K, give a person a cool feeling

Park Square:

3000K-4000K, to create an atmosphere and relaxation

The above is for outdoor lighting on the color temperature selection of the proposal, if you have any questions, feel free to contact us, our professional and technical staff will be free to serve you.

Relevant Reference Selection Factors

In addition to the above recommended color temperature, there are some other factors to consider:

Light Pollution:

Too high color temperature and light intensity may lead to light pollution problems and adversely affect the ecological environment.

Therefore, when we choose the color temperature of LED street lights, we need to avoid too high color temperature and over-illumination to reduce the impact of light pollution.

Color Reproduction:

For certain scenes, such as art exhibitions, commercial displays, etc., LED luminaires are required to have high color reproduction.

The average color rendering index (CRI) can measure the color reproduction of LED bulbs, generally CRI greater than 80 LED bulbs with better visual effect.

In specific scenarios, a higher CRI value may be required to ensure that the object's true color rendering. For example, museums, galleries, etc.

Conclusion

In conclusion, the choice of color temperature is a comprehensive issue that requires consideration of a balance of several factors. Therefore, when designing a lighting scheme, it is recommended to discuss with a professional lighting designer or technician and make a reasonable choice based on the specific application requirements.

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