Dimmable hid lighting

[withoutfear]

Any ideas on dimming Metal Halide Lighting?

[millamber]

Not really possible without either a Sinewave dimming system, and even then only slightly, or using a DMX Douser device or Hood.

The big sporting arenas use hoods by Musco to shutter the field/court lights when they do player intros or special events. But that isn't the same as dimming the output, its just a way to block output without unstriking the arc.

While I don't recommend it, I have seen places that use relay modules to turn on and off HID lights from the console, but since it takes 5 minutes for the units to come up to temperature and another 10 minutes to cool before they can be restruck, this is only used rarely.

Is there a specific reason you are asking, or are you just wondering?

[Esoteric]

What Chris said. There is a reason they generally aren't used in that application.

Mike

[withoutfear]

Im asking becasue we are moving into our gym with 8 hid lights and we would like to continue using them only for financial reasons.It would save us 10,000 dollars and time (says the electrician vs cans and halogens on a 20' tall room). I have found dimmable hid ballast and read several articles that say dimming is possible. I just wanted expert knowledge rather than a google article.
We aren't wanting the lights off just not at full bright. We will have foh, up lights, and down lights installed for the stage. So it's more about making sure the congragation can 1) read along and 2) not fall asleep during service, somewhere in the middle.

[Steve Vanciel]

Originally Posted by withoutfear

I have found dimmable hid ballast...
We aren't wanting the lights off just not at full bright.

You might compare the cost of the ballasts, installation and dimming circuits against the cost of a DMX color scroller. It would be possible to load the scroller with several gradations of Neutral Density gel to achieve different output levels and you could even add some color correction (HID's generally have a terrible color output). No dimmers would be required, only some extra DMX channels on your controller. Scrollers are available for various sized lights. You would have to come up with some sort of a mounting bracket since the HIDs probably do not have color frame slots. Which brings to mind a question: do the lights currently have a cage to protect them from wayward balls?

SteveV
Orlando, FL

[Esoteric]

I am not sure I have ever seen a scroller (aside from the ones they use for the huge Alphas) that would completely cover the output area of any HID light that I have ever seen. But if they did that would be your best budget solution. But there are a myriad of options you could do for less than tens of thousands of dollars. Depending on the size of the gym you might even be able to get in at around $20k or so to do it right. I am reasonably sure you could get an LED solution in that range, and depending on how picky you are you might be able to get an incandescent solution.

If I were specing the job I would suggest keeping the HIDs for work lights and adding LED house lighting to the area where the congregation will be sitting. This way you can concentrate coverage and get the most bang for your buck.

Mike

[withoutfear]

Can you give me some more info or a link to find more info on the lighting hood by musco i can't seem to find anything.

[RickR]

Try contacting Musco.com directly.

I think you're into a a custom unit. The dowsers mentioned above are usually fitted to stadium fixtures that are very different than the "high bay" fixtures you probably have in the gym.

I agree with Mike. I would keep the existing stuff (only because there isn't a reason to tear it out) and install some cheap incandescents or maybe LEDs. Gym light levels are usually far brighter (3-5x) than church seating needs. Plus you have that color to deal with...

Is there someone in your town with real lighting knowledge? They can visit your building and help sort through the options.

[millamber]

As much as I dislike them, you could most likely do a 1 to 1 swap of the high bay units to a florescent high bay unit. With florescent you could dim (with correct ballast installed) or many use a 3 circuit type to give different levels of brightness.

As Richard said, the hoods are mostly for stadium units, much different than a high bay.

[Steve Vanciel]

So, what are the dimensions of your HID fixtures? And, just how bright are they (watts, lumens, footcandles)?

SteveV

[D.R.HADDOCK]

If floros can be dimmed,
then metal halides could also be dimmed,
As both lamps are discharge lamps.
How ever, how well it works is another thing.
Also special ballasts will be needed,
they could be expensive.
Could be a costly experiment.

[withoutfear]

For what we want, the hid's just wont work. We need to be able to dim and turn on say after a illustration video ect. the only option to use the HID lights would be to install hoods on a solenoid and that's just not something we are going to do. I'm currently trying to find other alternatives. Thanks for all the response.