Average illuminance (Eav) = luminous flux of a single lamp × number of lamps (N) × space utilization coefficient (CU) × maintenance coefficient (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 fixture that reaches the floor and work surface, so it is related to the design, installation height, room size and reflectivity of the lighting fixture. The 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 and 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 fixtures, the light output capacity of the lighting fixtures 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. Coefficient. Generally clean places, such as living rooms, bedrooms, offices, classrooms, reading rooms, hospitals, high-end brand stores, art galleries, museums, etc., the maintenance coefficient K is 0.8; while general stores, supermarkets, business halls, theaters The maintenance coefficient K of places such as machining workshops and stations is 0.7; and the maintenance coefficient K of places with a larger pollution index can be taken to be about 0.6.
