brummydave
Senior Member
In this day of LED lamps where the wattage is not always an indicator of light output why is the lumens quoted so variable and often a missing statistic?
To add further confusion, when trying to replace older incandescent or halogen lamps it is near impossible to find a lumens figure for them to then compare with new.
I'm aware that colour temperature is a factor, but cool white only adds 10% or so it seems.
Currently I've been asked to replace Par 38 80W lamps in some recessed ceiling fittings.
Option one is replace lamps with £3 like for like.
Option two is replace lamps with CFL or LED... but working out which one will be trial and error rather than calculation from figures. Not very practical.
Option three is replace entire units but again getting the right amount of light is proving to be a theoretical headache.
After MUCH longer than i'd have liked i've found some info from over a dozen websites but with some quoting 1700-2100 Lm for a standard PAR and an 'equivalent' LED having 800 or 1000 or 1600... how's that helpful?
Any help or lighting level guidance i've missed would be gratefully received.
If I have to go to every lighting job with a light level meter, measure LUX and then do calculations to work out required light fittings, will this work out faster? It may be the only way it seems!
To add further confusion, when trying to replace older incandescent or halogen lamps it is near impossible to find a lumens figure for them to then compare with new.
I'm aware that colour temperature is a factor, but cool white only adds 10% or so it seems.
Currently I've been asked to replace Par 38 80W lamps in some recessed ceiling fittings.
Option one is replace lamps with £3 like for like.
Option two is replace lamps with CFL or LED... but working out which one will be trial and error rather than calculation from figures. Not very practical.
Option three is replace entire units but again getting the right amount of light is proving to be a theoretical headache.
After MUCH longer than i'd have liked i've found some info from over a dozen websites but with some quoting 1700-2100 Lm for a standard PAR and an 'equivalent' LED having 800 or 1000 or 1600... how's that helpful?
Any help or lighting level guidance i've missed would be gratefully received.
If I have to go to every lighting job with a light level meter, measure LUX and then do calculations to work out required light fittings, will this work out faster? It may be the only way it seems!
Last edited by a moderator:
