Interpretation of calculation results

Interpretation of calculation results

1. Scrutinize critically

  • To prevent glare – check the luminance conditions in the room.

2. Maintenance factor 

  • Has the maintenance factor been adapted to a maintenance plan for the lighting installation?
  • NOTE: The maintenance factor affects the lighting installation’s energy consumption. It is important to take into account the correct L-values and any luminaires with CLO.

3. Calculation conditions

  • Have the conditions for the lighting calculations been checked?
  • Has the size of the working area and immediate surrounding area been established?
  • Has the calculation area for the peripheral surrounding area been defined?
  • Has the calculation area for the room's brightness, walls and ceiling been defined?
  • Has the size of the calculation range of the cylindrical illuminance been determined?
  • Do the room surfaces' reflectances apply?
  • Has the luminaire’s average luminance been checked in rooms used for working with display screen equipment?

4. Uniformity requirements

  • When calculating uniformity illuminance, i.e. the ratio between the minimum value and the average value in the working area and the immediate surrounding area, it is important that the distances between the calculation points are documented and follow the recommendations of EN 12464-1.

5. Significance of gradient

  • Excessively large differences in illuminance and the luminance within the normal field of view can cause vision difficulties. Therefore, the scales for changes in illuminance and the luminance indicated in the standard EN 12464-1 should be used.

6. Limit values of luminaire luminance for working with display screen equipment

  • Verify that the luminaire's average luminance does not exceed the limit value according to 12464-1.

7. UGR glare number

  • Check, where appropriate, that the system’s average glare number conforms to the value stated in the standard.

8. Energy efficiency

  • Are the Swedish Energy Agency's recommended limit values for energy consumption for lighting in rooms (LENI numbers) being complied with?