In light of hearing that mercury vapor will eventually be banned, I have to discuss a couple of things. Granted, I haven't done a ton of research, but I would like to raise a few questions as well as a few possibilities that could be explored.

The first issue is "dark sky preservation". I own a $1200 telescope and love astronomy. I also have an interest in outdoor lighting and appreciate the reliability and ethereal qualities of mercury vapor.  A clear merc emits precise bands of yellow, green, deep blue, and violet. If the fixtures or bulbs could be designed to filter some of the blue and violet, these lamps would be closest to Low Pressure Sodium in the ability for astronomers to filter out the light.

And here's the next point.

The most efficient and strongest light emmission in clear mercs is in the yellow and green. The majority of the rest besides the blue/purple is in the UV spectrum. If I understand things correctly, phosphors are the best at creating green/yellow...so why not use the surplus UV for this? I understand that lamps similar to this (long ago) have already been designed, but why is an improvement in efficiency so marginal? It just doesn't add up. I'm talkin' lamps that show bright yellow/green when first fired up...not red, orange, or purple.

Which leads to the next point of importance.

The landscape. Plants and trees need a dark cycle. Foilage is most responsive to red and blue light for growth but need a dark cycle to produce sugars for survival. Red is overly abundant in High Pressure Sodium and blue (and red) in Metal Halide. Plants are blind to green light and minimally sensitive to yellow (I think...feel free to correct me), so the perfect candidate is MV.

Finally, efficiency. Mercs are only half as efficient as standard fluorescents but if we outlaw them based on that, then all incandescents should go as well. Incandescents are only half efficient as mercs. Besides, Metal Halide, which seems to be so popular these days can drop to merc output levels of the same usage (old good quality mercs, that is) before half of their life...I've seen it. Also, MH still tend to explode.

So what are we trying to accomplish by abolishing mercury vapor? Efficiency? We've discussed that...I sincerely believe they could be made more efficient with the proper phosphors. What about color redering? HPS certainly doesn't score in this department. If anything, a green merc blends well with the nightime environment and is nicer on the vegetation while HPS resembles burning cities and general mayhem. How about dark skies? Metal Halide is the astronomer's worst nightmare and HPS has messy color bands. How about environmental waste? We might as well abolish all forms of light and use candles or LEDS.  Feel free to comment. I'd like to hear it.

Don


 

you should explain that to the dark sky!!!

also Dark Sky wants to ban mercs because there's mercury inside....hey MH has the same amount of mercury inside as Mercury vapor....then they should ban MH and fluorescent lights because fluorescent lights have even more mercury in it than mercury vapor or MH!!!!

The dark sky does not know anything about lightbulbs and thinks mercury vapor has the most mercury inside just because of the word "Mercury"  I believe dark sky should have the lighting expert do this...not them!......

And how do you think the plant lovers will feel about HPS killing all of the plants?

oh boy!

also if possible please post the exact same thing you just said to other lighting groups!

I've always preferred mercury vapor over any other light source, it has better color rendering than high pressure sodium and longer life than metal halide. 

I also prefer mercury vapour. Here's an idea, create a petition to prevent mercuries from being banned 

yep I agree there should be pentition
but we gotta make sure we explain that HPS is orange and MV is more white and stuff so other people and I mean normal people will know which is which and sign that they want MV!

Bear in mind we wont want to get SOX\LPS banned though. I hope I will be in a better place before SOX\LPS is no more 

I highly doubt LPS would ever get banned...
1. It is very efficient... the most efficient.
2. They do not contain mercury.
3. They are easiest to filter for astronomers.
4. I believe that the monochromatic light output has the least effect on plants because there is no blue or red...only yellow.

I also have a technical question for some of the members who are...well...technical. As I was driving home from work in the dark...as it gets dark early now...and looking at the clear mercs lit, I was thinking about phosphors. Normally, phosphors are added to improve the light spectrum in mercs. Namely red. It adds to the color output. But in physics, if I'm correct, anything that is "resonant" to the output...whether it is sound, or light, or vibration, will AMPLIFY the output. In other words, phosphors that duplicate the exact wavelegths of mercury vapor's yellow and green, would increase the light output by a large margin. The UV rays would be put to proper use to INCREASE light output instead of making it prettier.

So, I'm wondering if producing RESONANT phosphors is the big engineering challenge. I think merc efficiency would skyrocket if this could be done.

   

I highly doubt LPS would ever get banned...

I highly doubt it as well. In case if it did I'll scream and\or have a fit 

Please this topic is about mercury vapor getting banned....please continue this about mercury vapor since the topic about LPS being banned is kinda off topic....of the title "Re: Can Mercs be saved?"...........Also I am hoping mercury vapor bulbs will not get banned...only the ballasts.....so the older fixtures in my town can continue lighting the roads!

Hi Max,
Glad you responded to this...as I wondered what you would think when I wrote this.

I'm glad you answered my question about phosphors. One thing I should be more specific about on color efficiency is the "apparent lumen output"...that is, color wavelengths that the human eye most responds to as opposed to actual energy output. In reading about LPS lamps, the bell curve of light response of our eyes seems to peak at the yellow wavelength and green is right next to it. Besides, modern fluorescents that are warmer in color seem to have higher lumen output compared to cooler ones with more blue...i.e. daylight.  Also, in observing specially colored fluorescents, the ones that are green or yellow seem to be the brightest.

As far as the dark sky issue, yes, the fixtures are the main issue, however, the message gets lost when talking about banning bulbs as opposed to banning fixtures.

I see your point about U.S. metal halide as opposed to European metal halide, as I've heard the same thing...however, this is about comparing bulbs that are *available* in the place where certain ones might be banned. Metal halide is gaining ground, but it continues to be very expensive and unreliable...I'm sure it will improve as time goes on.

As far as color, it is a matter of preference. But there are many areas that don't seem to favor HPS because the color is too harsh. HPS is readily available in most lighting stores but clear MV continues to be installed by both residences and businesses at least in my area. And, again, though clear merc is unflattering on human skin, it seems less invasive on the night time land scape...with proper fixture of course, as compared to HPS.

Yes, mercury vapor will always be the least efficient in HID lighting, but, as far as *banning* it, I have to question WHY. I have yet to hear a valid reason.

Don

 

well I heard Dark Sky said mercury vapors are just excuse for cheap yard lights and they want it to stop because of the bucket lights........but what I think they should really be doing is shielding them...not banning them because if mercury vapors are banned...guess what will happen.....they will start making MH bucket lights for residental and make it cheap...and guess what...it would be worse for dark sky cuz they are BRIGHTER....I think they should make a law about shielding bucketl lights or make a different design and ban the bucket shaped fixtures instead of banning mercury vapor

also dark sky wants to ban mercury cuz it has mercury in it....BUT  HEY fluorecent tubes has MORE mercury...so does MH that has same amount of mercury.....they don't regonize it.....it's just cause the Mercury Vapor's name! thats IMO......

Also they say they can't filter out the greenish color....but I don't really believe that in some ways......Ask Dave for some stuff...we talked a lot about this....

It was always my understanding that the blue and violet light is hardest to filter because it "scatters" in the atmosphere.  In the daytime, the sky is blue because the blue part of sunlight scatters all over the sky. As I mentioned earlier, I believe bulbs or refracters could be designed to reduce some of the bluer part of spectrum...but, again, the issue goes back to fixtures.

Yes, Jace, I think it's already starting to happen. "bucket lights" are becoming MH. And I don't care what anybody says, MH light would be the hardest to filter. Even the Darksky folks agree. It is an issue about fixtures as opposed to bulbs...and that was the whole point of this discussion!

Yep I noticed mercs are far less light polluting than HPS. I say BAN HPS!