2x18w T8, square, surface-mounted luminaire ... exists?

[DaKid]

Further to my previous thread regarding daylight lighting (eye-opening!), I've started a separate thread as I hopefully near the end of my search for lighting for my new study!

Firstly, please feel free to check my calculations. Assuming I'm aiming for around 750 lux, provided from three separately-switched fittings so that I can drop to 250 lux for relaxing (it's a home-study) but have high light levels for detailed work not on the computer, I've worked out that - given my 8.3 sq.m room (2.3m x 3.6m) - I need around 6,000 lumens, which is 3 x 2 x Activa 172 18w daylight tubes. Does that make sense, or am I missing some fundamental way this stuff works?

So, to the main question. I'm looking for a non-ugly way to display them in my study, given that a suspended ceiling is out (because of ceiling height). I'd therefore really like to try and find some square (i.e. 2ft x 2ft) fittings that'd take twin 18w tubes, which would ideally send the light out to the sides as well as down. Displayed metal is a bad thing (according to the wife), so we're looking at ideally only a cover/diffuser displayed, but otherwise white would be acceptable (but definitely not silver).

Does anyone know of such a thing? It needs to be mountable on the ceiling.

Thanks in advance for any advice

 

[333rocky333]

Twin 18 watt tubes were always rare in 600 x 600 modules, maybe due to the fact 2 tube 36, 40 and 55 watt PLL lamp fittings were available and brighter,

3 and 4 tube 18 watt modules were guite common but its all moving over to T5 HE lamp stuff now.

 

[big-all]

6000 lumins thats the equivilent to 4 100w bulbs and a 60w bulb that one dazzeling room half that would be more normal but off course i havent read your other thread

 

[ban-all-sheds]

Assuming I'm aiming for around 750 lux, provided from three separately-switched fittings so that I can drop to 250 lux for relaxing (it's a home-study) but have high light levels for detailed work not on the computer

Why not use a dimmer?

Or put in a separate lighting system (e.g. wall lights) for when you don't want the task lighting, rather than imposing artificial constraints on what characteristics the task lighting has to have so that it can also fulfill a non-task lighting role?

What's the work area like? Could you have something as simple as a shelf above it with a tube underneath concealed by a pelmet?

 

[DaKid]

Some good replies - as usual - and challenging many of my assumptions too.

What is unavoidable is the desire for full spectrum lighting, and the previous thread pointed to fluorescent as the best way to achieve this (rather than multiple spots). How best to have pretty looking fluorescent lighting in a room without suspended ceiling?

Separately, can you have dimmers for fluorescent lights??

 

[ban-all-sheds]

What is unavoidable is the desire for full spectrum lighting, and the previous thread pointed to fluorescent as the best way to achieve this (rather than multiple spots). How best to have pretty looking fluorescent lighting in a room without suspended ceiling?

Like I said, does it have to be on the ceiling? (You can get an anti-glare hood for your Eizo CG275W..... ).

Have you looked to see if that type of tube is available in 2D format? (probably not, but you never know).

Separately, can you have dimmers for fluorescent lights??

Yes. Not ordinary ones, and you need the ballasts to be the right sort, but yes. To keep control cost down you want ballasts which do 1-10V dimming, not 0-10V. They are completely different systems - with the former the ballast provides its own control voltage which goes to the 1-10V dimmer (MK make one - I'm sure there will be others).

With the latter you need to provide power to the dimmer and it sends the 0-10V control voltage to the ballast (or it talks to a dimmer pack using a protocol such as DMX or DALI which provides the control voltage).

The latter is overkill if all you want is a knob to twiddle, but might be of interest if you want to get into automation.

See //www.diynot.com/forums/viewtopic.php?t=236100&start=0