**Lighting Design for Schools and Libraries**
1. **Requirements for School Lighting**
The purpose of school lighting is to provide a good lighting environment for visual tasks in educational activities, meeting the visual needs of students and teachers, protecting eyesight, and improving teaching and learning efficiency.
While daytime teaching is predominant in schools, consideration must also be given to evening classes and self-study activities. In addition to natural lighting, classrooms must be equipped with artificial lighting. These lighting fixtures should be controlled by switches according to different zones to effectively compensate for the lack of natural light. On sunny days, direct sunlight may enter the classroom; thus, curtains or blinds should be installed to protect eye health.
School lighting should not only meet visual task requirements but also ensure safety, reliability, ease of maintenance and repair, and harmony with the environment.
2. **Lighting in Ordinary Classrooms**
**(1) Illumination Standards**
The illumination standards for school rooms can be selected according to Table 5-1. However, for classrooms used by adults in the evening and general classrooms in higher education institutions, the illumination standards can be increased by one level. The vertical average illumination of the classroom blackboard should not be less than 200LX, with a uniformity of over 0.7 above the average classroom illumination.
**Table 5-1 Illumination Standards for School Rooms**
*Note: The illumination standards in this table are extracted from the GBJ99-86 architectural design standards for primary and secondary schools. The values taken are median values. For general classrooms in higher education institutions, the illumination values range from 150-300lx, with a uniformity of no less than 0.7, as per the JGJ/T16-92 electrical design specifications for civil buildings. However, according to the International Commission on Illumination (CIE) standards, the illumination values are more than double those listed above.*
**(2) Light Source**
Classroom lighting is recommended to use GUIHAI T5 or T8 straight tube fluorescent lamps, which have high light efficiency, good light color, low brightness, and can easily meet the requirements for illumination uniformity.
**(3) Selection of Lamps**
It is advisable to use GUIHAI open-type lighting fixtures with a certain protective angle and an efficiency of no less than 75%, or GUIHAI batwing-type fixtures that can reduce the light intensity distribution in the glare zone and light curtain reflection zone, thereby reducing glare, especially the interference from light curtain reflection. This increases the effective light intensity distribution in the effective area, significantly improving the utilization efficiency of the output luminous flux.
Fixtures with high brightness or full mirror light control covers are not recommended. Ordinary classrooms are small in size and should use GUIHAI single-tube or double-tube fluorescent lamps, which are easier to achieve uniform illumination and energy savings.
**(4) Arrangement of Lamps**
The arrangement of lamps depends on the size of the classroom and the direction of the desk arrangement. Generally, the long axis of the lamps is arranged parallel to the students' line of sight, which has the following advantages:
- a) Uniform illumination and light curtain reflection are light;
- b) For fixtures with a small protective angle, direct glare can be reduced;
- c) The direction of the lighting and natural light projection are consistent, which is effective for auxiliary lighting and can avoid shadows;
- d) The direction of the lamps is the same as the students' line of sight, enhancing the sense of spatial direction and making it easier to focus attention on the blackboard;
- e) The brightness distribution should be uniform and reasonable. The hanging height of the lamps affects the lighting effect. To ensure uniformity, the distance-height ratio (L/H) should be greater than the maximum allowable distance-height ratio of the lamps used (both A-A and B-B directions should be checked separately). If the above conditions are not met, the arrangement of lamps or the type of lamps should be adjusted to meet the requirements.
**(5) Blackboard Lighting**
If only general lighting is set in the classroom, the vertical illumination of the blackboard will be very low, and the uniformity will also be poor. Therefore, dedicated lamps should be set for blackboard lighting, with the following requirements:
- A. It is advisable to use special lamps with asymmetric light intensity distribution characteristics. The protective angle on the student's side should be greater than 40°, so students do not experience direct glare.
- B. Blackboard lighting should not cause direct glare to the teacher or reflective glare to the students. During design, the hanging height of the lamps and the distance from the blackboard wall should be reasonably determined.