working out lighting levels

[Farmelectrics]

am i right we have an office area of 20m2 so we calculate the number of fittings times there lumen output which in our case is 2700 lumens times 6 = 16200 divided by 20 = 810 lux have i done this properly

 

[Farmelectrics]

the correct lux level for an office area is 500 lux at what height is that measured desk height eye height etc

 

[Farmelectrics]

doing a bit of googling ive notiched 2 other values must be added to the calculation cu of 0.6 and llf of o.8 so my new calculation would be 2700 x 6 x0.6 x 0.8 divided by 20m2 = 388lux that seems better any lighting experts out there lol

 

[sjhall]

Hi mate, how many office do you have to light?

Anstel & others offer a free lighting plan when you call a rep out .

I have a large lighting plan here for a factory & offices.... I can email it you so you can look through it, it has all the cals , lux levels etc .

 

[Andy78]

As said get a lighting rep to spec your room plan for you. The calculations are extremely complex for multiple fittings and are best done with software. You would need to include ceiling heights, angles and distances to work planes, available natural light levels, the reflective capacity of the walls etc etc.
As a very general rule of thumb, at average ceiling heights for offices, plan for two grid tiles in from the wall to a fitting, and 3 tiles max between any 2 fittings. This only works with a grid ceiling of course.. lol.

 

[Farmelectrics]

thanks for help guys they dont think like that were i work sort of make it up as they go along changing lots of these 600 x 600 to led types now people are complaining there to bright in office areas i have suggested your ideas to them falls on deaf ears there blaming the white walls now saying the light reflects of them even painted a couple of walls grey been in with are lux meter not saying how accurate that is but the meter is reading 800 lux in some offices were there ment to read 500 lux ive suggested removing a couple of fittings lol awiting my reply

 

[Farmelectrics]

sjh ive pm you my email adress

 

[atm84]

Needs to be done with software. Ask at your local wholesaler. They may offer lighting design for free.