Detail of GB 50033-1991

Introduction of GB 50033-1991

1 General provisions 1.0.1 This standard is formulated in order to implement the national technical and economic policies, make full use of natural light, create a good light environment, save energy, make the design advanced in technology, economical and reasonable, and benefit the production and protect eyesight in the daylighting design of industrial enterprises. 1.0.2 This standard is applicable to new projects in industrial enterprises that take natural light for daylighting, and can also be applied to renovation and expansion projects. 1.0.3 In addition to this standard, the design of daylighting shall also meet those stipulated in the current relevant standards of China. 2 Daylighting criteria 2.0.1 This standard shall take daylighting coefficient C as the quantitative index of daylighting design. The daylighting coefficient of a certain point in the room can be calculated using the following equation: (2.0.1) where, En——the indoor illumination at a certain point of the site (1x); EW——the outdoor illumination of the site at the same time as indoor illumination at a certain point (1x). 2.0.2 The selection of standard value of daylighting coefficient shall meet the following requirements: 1. The side daylighting shall take the minimum value of daylighting coefficient; 2. The top daylighting shall take the average value of daylighting coefficient; 3. The room with side daylighting and top daylighting can be simplified into side daylighting area and top daylighting area, which take minimum value of daylighting coefficient and the average value of daylighting coefficient respectively. Note: The calculation point of daylighting coefficient can be determined according to Annex II of this standard. 2.0.3 The standard value of daylighting coefficient on the working face of the workplace shall meet the requirements of Table 2.0.3. Table 2.0.3 Standard value of daylighting coefficient on working face in workplace Daylighting grade Visual operation classification Side daylighting Top daylighting Accuracy of operation Minimum size d (mm) of recognized object Indoor natural illumination (1x) Daylighting coefficient Cmin(%) Indoor natural illumination (1x) Daylighting coefficient Cav(%) I Particularly elaborate d ≤ 0.15 250 5 350 7 II Very elaborate 0.15＜d≤0.3 150 3 250 5 III Elaborate 0.3＜d≤1.0 100 2 150 3 IV Less elaborate 1.0＜d≤5.0 50 1 100 2 V Rough d≥5.0 25 0.5 50 1 Notes: ① The values of daylighting coefficients listed in the table are applicable to Category II light climate zone in China. The daylighting coefficient is determined based on the outdoor critical illumination of 5000 1x. ② Daylighting grades classified by production workshops and workplaces can be subjected to Annex III of this standard. ③ The daylighting grade for Classes I and III visual operations with small brightness contrast can be improved by one grade. 2.0.4 Light climate regionalization shall be determined according to Annex IV of this standard. Light climate coefficient of each light climate region K shall be adopted according to Table 2.0.4. The standard value of daylighting coefficient one site shall be multiplied by the light climate coefficient K of the region. Table 2.0.4 Light climate coefficient K 2.0.5 For daylighting by single-layer ordinary glass fiber reinforced plastic window in Category III light climate region, the window opening area can be estimated according to the window-to-floor ratio listed in Table 2.0.5. The window-to-floor ratio corresponding to building dimensions can be determined according to Annex V of this standard. Table 2.0.5 Window-to-floor ratio Ac/Ad Notes: ① Calculation conditions: For rooms with Grade I daylighting, calculate as weighted average value pr of reflection coefficients of cleaning workshop and indoor surfaces is 0.5; for rooms with Grades II to V daylighting, calculate as the general pollution and its weighted average Pl is 0.3. ② The window-to-floor ratio in other light climate regions shall be multiplied by the light climate coefficient K given in Table 2.0.4. 2.0.6 For buildings with Grade I and II side daylighting and rectangular skylight lighting, when the window area is limited, the daylighting coefficient can be reduced to Grade III, and the reduced natural illumination shall be supplemented by other types of daylighting or artificial lighting, but the total illumination formed by natural daylighting and artificial lighting should not exceed 1.5 times the standard illumination specified in this standard. 2.0.7 In daylighting design, windows with good daylighting performance shall be selected as external windows. The daylighting properties of external windows can be inspected according to the current national standard Graduation and test method of daylighting properties for external windows. 2.0.8 The building design shall consider convenience for window cleaning and maintenance. Clean windows regularly, not less than once a year. 2.0.9 When it is necessary to check the actual effect of daylighting design, follow the current national standard Method of daylighting measurements. 3 Daylighting calculation 3.0.1 The dimensions of window openings shall be estimated and determined according to Table 2.0.5 and Annex 5 of this standard, and lighting calculation shall be carried out. Daylighting calculation points shall comply with the provisions of Annex II of this standard. 3.0.2 In the case of top and side daylighting, the daylighting coefficient value can be calculated using the following equation: I. Top daylighting:

Contents of GB 50033-1991

1 General provisions 2 Daylighting criteria 3 Daylighting calculation 4 Daylighting quality Annex I Glossary Annex II Determination of calculation points Annex III Examples of daylighting grades of production workshops, workplaces and auxiliary buildings Annex IV Light climate regionalization in China Annex V Window-to-floor area ratio corresponding to building dimension Annex VI Daylighting calculation parameters Annex VII Calculation of discomfort glare of side window Annex VIII Explanation of wording in this standard Additional explanation