Low energy Dimmable House Lights

[techtech]

Hi All,

 

Can anyone recommend good low energy dimmable house lights to fit into a standard BC fitting? I would be running them of ETC 5kw and 3kw dimmers.

I tried one sort but the dimming curve was not brilliant - faded to about 10% then snapped out.

 

Any thoughts would be much appreciated!

 

Thanks

 

TT

[david.elsbury]

By "low energy" do you mean compact fluroescent? AFAIK most have a poor dimming curve towards the lower 10% of the range- as you've noted, some just snapping off.

I',m sure we've covred dimming CFLs recently, have a look thru the search function for more.

[Tomo]

I tried one sort but the dimming curve was not brilliant - faded to about 10% then snapped out.

That actually sounds very good for a 2-wire dimmable fluorescent. Which one was it?

 

Better results can be had with 3-wire (two lives plus neutral) and 4-wire (0-10v and DMX controlled) ballasts, but obviously that adds quite a bit of expense due to the extra cabling.

Compared to tungsten halogen you will probably still be disappointed - quite simply, the laws of physics get in the way.

 

For houselights, there isn't really a suitable replacement for halogen illumination.

 

LED isn't bright enough (yet) - I've been to one venue that has about 5 or 10kW of LED in a chandelier (I forget the exact size), but needs several kW of tungsten to illuminate the place as the chandelier doesn't actually produce enough light at ground level.

 

That said, LED makes a lot of sense for 'features' - anything that needs to be lit to look good but isn't the primary illumination for the space.

[J Pearce]

Use the halogen capsule replacements for inert gas tungsten lamps.

 

Still qualify as energy saving, and still look good.

[adam2]

If this is an existing install, then I would use incandescent lamps in the short term, perhaps for another year or so, and then review the matter.

Dimmable CFLs certainly exist right now, but as others post, have not given complete satisfaction, especially at the bottom of the dimming curve.

There is a huge demand for dimmable CFLs and I believe that improved products will soon be on the market.

 

If this is a proposed new install, then I would consider dimmable ballasts with either DMX or 3 wire control, as suggested above.

[rgye]

I spent months trying to solve this problem in a new theatre cum multi-purpose auditorium (representing the client's interests)

 

The spec called for low energy lighting and the M&E consultants assured us that we would be able to dim to 1% with compact fluorescents in decorative fittings, controlled by a Zero88 HF dimmer.

 

The results were ghastly. Tracking the dimming curve on the dimmer output I found that the lights stopped dimming at 30%, and then cut out as you tracked from 1% to zero. We had the M&E consultants back who did endless lux meter tests which demonstrated that the lights were in fact dimming to 13% before they cut out - if you didn't mind waiting two minutes for the light levels to stabilise at the bottom of the curve. We talked to the manufacturers who said the ballasts were designed to go down to 10%, which doesn't explain why the M&E people specified them for this job. We talked to the ballast manufacturers and to Zero88. There are 3% ballasts on the market but, inevitably, not at the power level for these fittings. There are, allegedly, some 1% ballasts on the market (Russian, I think), but the experts were all quite dismissive of them. The problem is that in terms of human perception, a fluorescent running at 10% or even 3% just looks like a somewhat dimmed lamp; the curve is far from linear. So even if you manage to dim to 3%, you are still going to encounter an ugly switch off (or switch on when raising the lights).

 

The lessons from this were that some M&E engineers at least, even quite distinguished ones, have a pretty hazy grasp of dimming technology, and compact fluorescents are fundamentally unsuitable for theatre standard auditorium lighting. Strip fluorescents can be made to dim reasonably well to zero, but they look awful.

 

In our case we declined to pay the last installment of the M&E people's fee, which they took on the chin, and we now only use the CF system for non-theatre uses of the space. For theatrical use we have installed a completely separate tungsten system.

[bob_lamb]

I spent months trying to solve this problem in a new theatre cum multi-purpose auditorium (representing the client's interests)

 

The spec called for low energy lighting and the M&E consultants assured us that we would be able to dim to 1% with compact fluorescents in decorative fittings, controlled by a Zero88 HF dimmer.

 

The results were ghastly. Tracking the dimming curve on the dimmer output I found that the lights stopped dimming at 30%, and then cut out as you tracked from 1% to zero. We had the M&E consultants back who did endless lux meter tests which demonstrated that the lights were in fact dimming to 13% before they cut out - if you didn't mind waiting two minutes for the light levels to stabilise at the bottom of the curve. We talked to the manufacturers who said the ballasts were designed to go down to 10%, which doesn't explain why the M&E people specified them for this job. We talked to the ballast manufacturers and to Zero88. There are 3% ballasts on the market but, inevitably, not at the power level for these fittings. There are, allegedly, some 1% ballasts on the market (Russian, I think), but the experts were all quite dismissive of them. The problem is that in terms of human perception, a fluorescent running at 10% or even 3% just looks like a somewhat dimmed lamp; the curve is far from linear. So even if you manage to dim to 3%, you are still going to encounter an ugly switch off (or switch on when raising the lights).

 

The lessons from this were that some M&E engineers at least, even quite distinguished ones, have a pretty hazy grasp of dimming technology, and compact fluorescents are fundamentally unsuitable for theatre standard auditorium lighting. Strip fluorescents can be made to dim reasonably well to zero, but they look awful.

 

In our case we declined to pay the last installment of the M&E people's fee, which they took on the chin, and we now only use the CF system for non-theatre uses of the space. For theatrical use we have installed a completely separate tungsten system.

 

M&E consultants will spec from a book rather than the wise old guys in the trade. Seen this many a time and im sure it wont be that last.