To understand the lighting needs of an industrial shed, it is necessary to perform a lighting calculation.The application contexts for industrial lighting are diverse and each with different needs: entrance areas, reception, offices, work and production areas, storage spaces, outdoor and transit areas.
A lighting solution must be designed to meet the quantitative and qualitative lighting requirements for the visual enjoyment of both an indoor and outdoor space (so-called application space).
The lighting system must provide efficient and optimal visibility at every point of the industrial shed, to ensure the safety of operations.
The lighting calculation for an industrial shed must be carried out correctly, in order to propose a lighting design that adequately meets both the height constraints of the interior ceilings and the safety and visibility lighting requirements for the large outdoor space.
The lighting calculation for an industrial shed is performed through the examination of a number of parameters useful for classifying the entire application space.
The main parameters to be considered are: the size of the room and its illuminance value, the type of luminaire to be installed, the utilization and maintenance factor, the value of wall and ceiling reflection coefficients and the level of maintenance.
Another important indicator is the performance parameters of the luminaires to be installed, including durability.
There are mainly two phases:
- with the first stage, a simplified calculation is performed, which allows the determination of the parameters described above;
- with the second stage, processing to obtain lighting parameters is performed with the help of a calculation software.
The lighting calculation methods to be applied are different, depending on the lighting design objective to be achieved.
For the artificial light objective, the total flux method and the point flux method are applied. For the daylight objective, the Daylight Factor (FLD) is considered.
The ‘Utilization Factor’ method allows an initial dimensioning of the lighting system ofan industrial environment, with the determination of the number of light sources required to uniformly illuminate the application space.
The maintenance factor takes into account the depreciation that the quality of the lighting system suffers, due to the reduction in luminous flux emitted by the luminaires during their operation.
The lighting calculation of an industrial shed is carried out by applying a calculation formula that allows, starting from the average illuminance values to be obtained, to determine the required luminous flux, i.e. the number of luminaires to be installed.
The units of measurement, which are used to perform the lighting calculation, are Lumen (lm), Lux (lx) and Nit (nt-candles).
If we apply the total flux method to perform the lighting calculation of an LED solution, the formula is as follows:
Ftot = A x Em / (u x MF)
- Ftot corresponds to the flux emitted by all luminaires;
- A corresponds to the area of the illuminated surface;
- Em corresponds to the average illuminance on the surface;
- u is the coefficient of use;
- MF corresponds to the maintenance factor.