How to reform school classroom lighting
Everyone knows that there are many problems with the current classroom lighting in primary and secondary schools: substandard illuminance, serious glare, low or high color temperature, blue light problems, stroboscopic problems, color rendering index, and energy consumption problems. There are many reasons for these problems, and they are long-term. Although the renovation has begun, the renovation of school classroom lighting is not accomplished overnight. What are the difficulties?
One, the standard is not standard. In fact, there have been national standards for school classroom lighting. Although the standards are relatively isolated and poorly compatible, these standards have always been on paper, and there is a big deviation from the real classroom scene. With the development of the times, the existing national classroom lighting standards are far from international standards and cutting-edge research in terms of indicators, design layout methods, intelligent control requirements, and lamp light source parameter requirements. They should really keep pace with the times. And for some classroom lighting indicators, there is still a lack of detailed specifications at the national level.
Second, the difference in the classroom. Our country has a wide geographical area and a large number of schools. The orientation, lighting, geographic latitude and climate zone of each school classroom are very different. How to study the effective use of natural light in the real environment and rationally plan the classroom lighting plan , Is a very detailed and cumbersome project.
Third, the differentiation of students. The physical and mental development characteristics of adult students and minor children are different. The lighting transformation of school classrooms should be based on real space scenes and the needs of different groups of people. Professional lighting design should be carried out, and natural light should be used as much as possible, and some professional technology should be combined. Create a high-quality light environment suitable for different student groups.
So what are the lighting standards for campus classrooms? Let's take a look now!
1. Excellent illuminance and uniformity of illuminance: According to the national standard GB7798-2010, the classroom desktop maintains flat illuminance ≥300, illuminance uniformity ≥0.7, blackboard maintains average illuminance ≥500, and illuminance uniformity ≥0.8. As of the end of 2018, more than 90% of the illuminance and uniformity of all the classroom lights in the 10,000 primary and secondary schools that we have renovated did not meet the requirements of the national standard. Even the illuminance of some school desks and blackboards is only more than 100 lux. Students studying in such a light environment for a long time can easily cause eyesight fatigue and cause myopia.
2. Anti-glare: The national standard stipulates that the glare value of classroom lighting is <19, and most school classroom lighting uses simple fluorescent lamp brackets, the light source is directly exposed, the light is very dazzling, and the glare value exceeds 22. As a result, the eye muscles are too tight, which seriously affects the students' ability to concentrate in class.
3. ,: Generally fluorescent lamps use AC power supply, the current changes periodically with time, and the flashing 100 times per second causes the brightness of the light to be unstable. When learning under the stroboscopic light source, the visual system needs to constantly adjust the pupils of the eyes. The size is used to protect the stability of retinal light intensity and the clarity of imaging. Long-term learning under this light environment will definitely make the pupil sphincter tired due to overuse.
4. Anti-blue light and other light hazards: The high-frequency and short-wave blue light between 400-500nm in ordinary LED light sources can cause irreversible damage to the eyes, such as the formation of myopia, to the macular disease area that directly penetrates the eyeball and reaches the fundus. In addition to the blue light hazards in traditional LEDs, there are seven harmful lights such as actinic ultraviolet, near ultraviolet, retinal heat, weak vision stimulation, small light sources, and infrared radiation. These 7 kinds of harmful light seriously harm our eyes and body to varying degrees.
5. Anti-light decay and prolong service life: Ordinary lamps will have serious light attenuation after half a year of use, resulting in a decrease in luminous flux, which will not meet the national low standard requirements. Currently, in order to maintain the lighting brightness that meets the national standard, the cycle of replacing the lamps It takes 2 to 6 months and requires long-term maintenance by relevant maintenance personnel, resulting in high maintenance costs and waste of resources.
6. Excellent color rendering index: the spectrum of ordinary fluorescent lamps is incomplete, resulting in color loss and color cast. Far from reaching the national standard Ra≥80, and the poor color reproduction ability of lighting fixtures will directly affect children's color discrimination ability.
7. Comfortable color temperature: The national standard stipulates that the color temperature is 3300-5300K, and the actual measurement result reaches 6500K. Too high color temperature will increase the proportion of blue radiation, and the blue light will also increase. Blue light will be aggravated due to genetics, nutritional environment, healthy habits and old age Related problems caused by macular degeneration. Late self-study for a period of time will also affect the secretion of melatonin in the students, reduce the quality of sleep, and affect the learning efficiency of the next day.
8. Resist the related hazards of fluorescent lamps: fluorescent tubes contain mercury, phosphors and other heavy metal substances. If mercury and heavy metal phosphors are improperly stored and disposed of, they will also cause great harm to the ecological environment. They can enter the ecology in various forms. The environment directly pollutes soil, air and water. Then enter the human body through the food chain, directly endangering human health, and the luminous efficiency of fluorescent lamps is low, generally fluorescent lamps are only 50lm/w. Although the fluorescent lamp emits light at 365 degrees, the light emitted in the opposite direction is basically useless. Although it is reflected back through the lampshade, the reflection efficiency is low and the energy consumption is too high. The ballasts in fluorescent lamps also emit infrasound waves that are harmful to the body.
