high frequency control gear with Tri-phoshor lamps T8/T5 ,
So 4 x 14W T5 ( 4 x 18W T8) in 600/600 module or LED dimmerable 45W 600/600 modules
both can have additional emergency lighting backup modules added

as to function room etc. I'd say plenty of socket to allow for plug in lamps for variable task light
may be LED wall lights if the bugdet will allow

I would focus on three things:

1 - what illuminance level do I need, can i meet that task lighting illuminance locally at the desk and avoid a high energy consuming general lighting system meeting that task lighting level everywhere - 500 lux and a cat 2 louvres is widely specified (still) and is a complete disaster from an energy perspective

2 - i would focus slightly less on the particular lumen package and more on the luminaire LOR - it's no good having a high performing lamp package if most of the light doesn't get out of the box - the metric should be the installed efficacy of the installation

3 - Daylight linking with dimmable control gear will give huge savings compared to comparisons between different luminaires

Do all three, and you should be able to show 80% savings over a "typical" office lighting scheme

Regards

Barney

I would like to see more of (3) with possible light piping from outside too: it offers a real saving when the sun is out like having solar PV but at probably a tiny fraction of the cost and space and complexity.

Rgds

Damon

You don't train them to dim the lights - just put the photocells in the right place - conect up to the relevant dimmable ballasts and hey presto - the luminaire modulates to give a constant illuminace level as daylight varies (it also has the davantage of dimming the fittings when new, as the light output will be higher - you effectively save 1/maintenance factor.

Depending on how far you want to go with controls, I would use manual on with absence off - in small groups as above. If it's a rasonable sized office, you could also consider links to corridor hold etc to avoid lone workers sitting in a small pool of light in a generally dark space

Good daylight is important for many reasons - let alone the significant energy savings when integrated with the lighting solution - just beware of the need to control glare though - you really don't want to engineer in a "blinds down - lights on" scenario by making the space too "bright" for the users. (Equally, 1 w of solar energy in = 1w of cooling power needed - so the balance has to be the energy saved from daylight compared with the winter heat loss through glazing and the solar gain in summer)

Regards

Barney

The cross sectional area of fibre optic would have to be at least as large as the light tunnel - more in fact! Unless light flux was mightily concentrated e.g. by fresnel lens, at the 'skylight' collection surface. It shocked me to discover how lossy fibre optic is, at piping light - I'd thought the whole point was that they were almost loss-less.

Posted By: fostertomThe cross sectional area of fibre optic would have to be at least as large as the light tunnel - more in fact! Unless light flux was mightily concentrated e.g. by fresnel lens, at the 'skylight' collection surface. It shocked me to discover how lossy fibre optic is, at piping light - I'd thought the whole point was that they were almost loss-less.

Ah I thought it might not be so simple. Someone on another thread (forget which) was mulling using fibre optics to shift light from a centralised, well cooled LED source and I thought if that would work then the same would go for daylight.

Could still be very pretty if not very efficient - but then daylight's for free..