Solar Street Lights: Illumination Calculation Method

Solar street light illuminance (lux lx) u003d luminous flux (lumens lm) / area (square meter m2), that is, the average illuminance of 1 lux (lx), is the luminous flux of 1 lumen (lm) illuminated on 1 square meter (m2) area brightness. When using this method to find the average illuminance of the floor of the room, in the case of the overall lighting fixture, the following formula can be used to calculate: Average illuminance (Eav) u003d luminous flux of a single fixture Φ × number of lamps (N) × space utilization coefficient (CU ) × maintenance factor (K) ÷ floor area (length × width). Formula description: (1) The luminous flux Φ of a single lamp refers to the total luminous flux value of the bare light source of the light source contained in the lamp. (2) The space utilization coefficient (CU) refers to the percentage of the light beam emitted from the lighting fixtures that reaches the floor and the work surface, so it is related to the design, installation height, room size and reflectivity of the lighting fixtures. The lighting rate also changes accordingly. For example, when the common lamp panel is used in a space of about 3 meters high, its utilization factor CU can be between 0.6-0.75; and when the aluminum cover of the lamp is suspended and the space height is 6-10 meters, its utilization factor CU can be in the range of 0.7- -0.45; when the downlight lamps are used in a space of about 3 meters, the utilization factor CU can take 0.4--0.55; and when the lamps such as light strip brackets are used in a space of about 4 meters, the utilization coefficient CU can take 0.3--0.5 . The above data are empirical values u200bu200band can only be used for rough estimation. If you want to accurately calculate the specific values, you need to provide the company in writing. The relevant parameters are here for reference only. (3) It means that with the aging of the lighting fixture, the light output capacity of the lighting fixture decreases and the use time of the light source increases, and the light source decays; or due to the accumulation of dust in the room, the space reflection efficiency is reduced, resulting in a decrease in illuminance. The maintenance factor K is 0.8 for generally cleaner places, such as living rooms, bedrooms, offices, classrooms, reading rooms, hospitals, high-end brand stores, art galleries, museums, etc.; while general stores, supermarkets, business halls, The maintenance factor K of theaters, machining workshops, stations and other places is taken as 0.7; while the maintenance factor K of places with a larger pollution index can be taken as about 0.6. In order to let everyone understand the above calculation formula more clearly, here is an actual engineering case: a machining workshop in Dongguan is 58m long, 18m wide, 8m high, rectangular, and the staff work surface is 0.8m. The ceiling is mixed with cement and soil structure, and the walls are painted white. After comprehensive consideration of all aspects, 250W metal halide light source is now used as lighting. After checking the 'Architectural Lighting Standard ManualHow many sets of lamps are needed? Solution: According to the indoor calculation formula: EAVu003d(Φ×N×CU×K)/(A×B) Check the data to get the parameters: (1) The total luminous flux of the 250W single-ended powder-coated metal halide light source is: Φu003d 18500; (2), CU u003d 0.65; K u003d 0.7 Substitute the above parameters into the formula: N u003d 49 (set).