Functional Lighting Design
A Guide to LUX light levelsOne key aspect of lighting design is to get the required lighting levels for a space which is dependent on its usage. The following table provides a guide to typically what LUX levels are appropriate for different applications.
|Description of Space||Comments||Light Level in LUX|
|Relaxation Area||Warm ambient space||120|
|Domestic Bedroom||Relaxation and Occasional Reading||200|
|Domestic Office||Computer and reading||250|
|Corridors/ Restroom||Occasional reading||150|
|Storage Area||No small print||150|
|Commercial Office||General Use||500|
|Retail Shop||Usage dependent||600|
|Sports Hall||LUX increases with level of sport||500|
|Car Park||Higher at entrance||100|
|Workshop||For detail work||750|
|Operating Theatre||medical work||1000|
Once you have analysed the usage patterns and requirements, then the next task is to design the adequate lighting, based on the LUX level requirements for the space.
Office Simulation Example
In this example we are using 600x600mm LED panels to light an office area. The first step is to select a luminaire which is in this case is a 600x600mmm LED panel and load the necessary light output data for this unit into the simulation. The industry standard for this is by using an IES file which provides details of lumens output and all angles from the lamp centre. In this example we have used DIALux as the simulation tool. From here the panels can be positioned in the ceiling in the initial desired position. A working level is then selected, typically 0.75m above the floor, to simulate the light level at and then the simulation can be run. It is normally necessary to then review the output and optimise the positioning and also possibly the number of panels to get the desired LUX level on the working plane. In this case we are looking for an average maintained LUX level of 500. The following diagram then shows the lighting design for the office area which can be seen with 14 LED panels placed in the ceiling to obtain the required illumination. As shown at the base of the chart we have achieved a maintained LUX level of 499 which is ideal. The concept maintained means that we have allowed a light depreciation of 20% over the life of the luminaire and consequently have selected a maintenance factor of 0.8. This means that the LUX level at the start of usage will be 625 LUX.
Office lighting Rendering
The illustration below then provides a 3D visual rendering which pictorially presents the lighting level in the space.