Author Topic: LEDs - Are they better?  (Read 263 times)

charnhoupito

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Re: LEDs - Are they better?
« Reply #15 on: January 18, 2018, 04:36:51 AM »
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Yes, this is one of the worst light polluting fixtures out there. Half the output spills uselessly horizontal or upwards. It'd be nice if the folks who dream up these "streetscape" projects with "vintage"/"historical" lighting would ponder if those streets were historically lit with the crazy intensity of today's glare bombs.

There are lots of "decorative" street light fixtures out there with LED's, and quite a few of them are actually cutoff designs.

Clear Skies,
Phil

Hey Phill, the city was out here replacing a burnt out bulb across the street from me yesterday. Too bad as it was out for the last 3 months and it was nice and dark in that direction. I went out to speak to him and asked him what kind of bulb it was? It was a 100 watt hi-pressure sodium and clear glass. I asked him if there where any type of bulb that had any type of cut-off so the light would just shine down and not 360* and light up everything....including my house! He didn't know anything about it. I asked him for the bulb so I might look around for a better replacement, but he said it was not safe to??? Anyway, he gave me the package that the bulb came in, so at least I have an idea what the size is if I want to look around for a better replacement?

BTW, I did have the electrical manager come out and put a "make shift" shield in front of the bulb so it did not shine directly into my bedroom after complaining last year, but need a lot more of them up and down my street and he's not going to do it! So i figure I could do some research on my own and if I could find a better solution I could buy a few of them myself and replace them.

Lauro Mason

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Re: LEDs - Are they better?
« Reply #16 on: January 20, 2018, 11:36:56 PM »
Retrofitting to LED lighting from HPS is typically not just a matter of swapping out a bulb if we're talking about streetlights.  Due to heat issues, LEDs typically require the FIXTURE to be replaced.

Clear Skies,
Phil

revekosque

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Re: LEDs - Are they better?
« Reply #17 on: January 21, 2018, 12:57:11 AM »
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Retrofitting to LED lighting from HPS is typically not just a matter of swapping out a bulb if we're talking about streetlights.  Due to heat issues, LEDs typically require the FIXTURE to be replaced.

Clear Skies,
Phil

Is there another type of bulb besides a LED that could be used? The one in the lamb has clear glass, maybe a frosted glass or one with a "cap" on the top?

Sean Meyer

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Re: LEDs - Are they better?
« Reply #18 on: January 23, 2018, 04:26:20 AM »
I'm very curious about this as well. They have silently, but expediently, been changing out the flat lens sodium lighting to LED's in Austin over the past couple years.

arovuzar

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Re: LEDs - Are they better?
« Reply #19 on: January 23, 2018, 08:35:20 AM »
Here are a few example of cut-off "decorative" street light fixtures.

http://www.acuitybra...luminaire-small
http://www.acuitybra...t-top-luminaire
http://www.acuitybra...-led-luminaire/

Clear Skies,
Phil

Ricky Mondal

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Re: LEDs - Are they better?
« Reply #20 on: January 23, 2018, 07:32:37 PM »
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Here are a few example of cut-off "decorative" street light fixtures.

http://www.acuitybra...luminaire-small
http://www.acuitybra...t-top-luminaire
http://www.acuitybra...-led-luminaire/

Clear Skies,
Phil

Thanks for the links. I'm going to Lowes with the current bulb and see if they have a replacement that is the same size and wattage and see if they make a frosted one or something besides clear.

bijstentetal

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Re: LEDs - Are they better?
« Reply #21 on: January 31, 2018, 03:14:23 AM »
On my way home from work yesterday I passed a utility contractors truck that was in the process of swapping out the streetlights and installing new LED fixtures.

This morning I got my first ever look at one in action and it brought a smile to my face.

Directional lighting!

Much, much better!

Woody Boelkens

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Re: LEDs - Are they better?
« Reply #22 on: February 03, 2018, 08:04:22 AM »
I noticed these kinds of streetlights when I was visiting family in Mt. Pleasant, SC, back in February of this year. Far better light control than the usual HPS ones with the sag lenses. I could see more stars than I was expecting to see that close to Charleston.

But I hear about LED installations that don't go as well, particularly in L.A. I'm trying to gauge an overall sense out there of the overall change, either better or worse. Some cities like Savannah and Raleigh are swapping out their entire inventory of streetlights for LED's and I'd really be interested in how observers in these locales gauge the change in skyglow.
Clear Skies,
Phil

propdiagairil

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Re: LEDs - Are they better?
« Reply #23 on: February 08, 2018, 10:54:44 PM »
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I think the primary difference you are seeing is that the new LED lights tend to emit directly downard and are usually also hooded (which blocks direct upward emission...
As I was driving home last night from Sunset Beach to Raleigh, it was striking how rapidly private businesses and homes (of the sort previously inclined to have sodium yard lights) are switching to LEDs - only a year ago between Sunset Beach and Wilmington, there was still virtually no private adoption of LEDs yet and only a smattering of municipal LED installations at new buildings or occasionally where an old sodium fixture was being replaced at the end of its life cycle.

SOMETHING THAT JUMPED OUT visually was how often private businesses are mounting the new LEDs at 45-degree angles rather than downward, such as to defeat any shielding built into the fixture and significantly reducing the benefit of the greater directedness of LED light. In short, old thinking habits about most "efficient" use of fixtures for illumination die hard, especially when the benefit they see to LEDs is far lower electric costs to run them the same way they did old sodium fixtures. They think this orientation allows them to use fewer fixtures and to shine light directly on a wider area, which seems more "efficient" to them - not understanding the reduced visibility the glaring exposure of eyes to bright direct beams causes. The one upside is that the greater directedness of LEDs doesn't seem to proliferate the beam quite as wide or diffusely (especially in moist conditions) as the old sodium lamps did - though the glare issue when the LED light is directly visible (because of the 45-degree rather than downward orientation) is much worse.

Jason Harlan

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Re: LEDs - Are they better?
« Reply #24 on: February 09, 2018, 05:29:51 AM »
Here are some photos from an astronomer friend (not on CN) showing the just installedLEDs in Binghamton, NY versus the older sodium lights. The photos are from her front yard, but not quite the same place, yet they show the same city residential street scene.

Things I see here:

 While the LEDs seem a little brighter, and are certainly more blue, their cut-off design shield her higher yard from the lights. Note that the old lights brightly lit uphouses on the street, while now the houses have no light on them!

 Her general impression is of less upward light from the LEDs, and it is probably an improvement.

 It would seem that the full-cut-off design here may end up with lower sky glow in the area. Only time will tell.

I have only seen these new LEDs during the daytime, and they are full-cut-off and mounted flat to the ground, so there is no upward aimed light.Attached Thumbnails