OT - replacing sodium flood lights with LED

Legume

Trying to figure out replacing some large sodium floodlights on a dock with LED fixtures.  Has anyone installed large, very bright LED floods?  Recommendations for source, brand, etc?  Will be exposed to salt air 100% of the time.

nolaegghead

Sodium lights are actually more efficient than LED in lumen per watt but much less efficient in effective "pupil" luminous per watt.  

Our street's sodium lights have been replaced with LED.  Looks different, a weird golf ball pattern, but the color is nicer.  

They should make nema 4x but I'm not certain.

clifkincaid

Night falcons! I've installed them on sports courts.

fishlessman

we had a company come in last year and give us several led lights to try out, hated most of the lights but eventually they found one that lit every corner of the shop and we replaced all the slow lighting metal halides. they do seem harder on my eyes and i would not take my biannual eye exams late in the day with these lights but the instant on off is a great feature.  let us know which light you go with, i need a lights badly on my docks

Legume

nolaegghead said:

Sodium lights are actually more efficient than LED in lumen per watt but much less efficient in effective "pupil" luminous per watt. 

@nolaeggheadI have a 3rd grader's understanding of lumens/candlepower and brightness.  Could you explain what you mean?  Not actually sure if lights are HPS or metal halide that will be replaced, someone's looking for a receipt now from the last time a bulb was purchased).  This all goes back to how big of a generator is needed - since the diesel generator finally died.  More efficient lights=less generator, etc.

One of the concerns of converting is will the light from an LED penetrate the water in the same way - these are used for night fishing on the coast - mostly specs

gdenby

I can give you some pointers. Before I retired, one of my ongoing projects was working out how to replace most of the lamps in the building for increases in efficiency. Spent several years trying out various LEDs.

LEDs are basically a point light source, emitting mostly blue light. By coating the LED lens w.various phosphors, the blue light is mixed w. other colors. For what you are doing, this is good, because blue light penetrates water quite well. There is a down side. At low light levels, humans don't see well in the blue end of the spectrum. Things tend to look ghostly, and washed out out. We're adapted to see firelight in dim environments. The LEDs will be rated by color temperature. They run up to about 6000K for a bright blue light and down to around 2300K for something similar to an incandescent light. I'd suggest that anything you look at have at least 4000K for water penetration.

Unfortunately, LEDs are not well suited for flood lights. Either the light has to pass through a diffuser, which dims the output, or the lamp has to be built w. the LEDs in an spread array. That's whats going on in the "golf ball" pattern nolaegghead mentioned. The models I tested a few years ago were fairly disappointing. About $150 for an array that only had the output of a 75W incandescent flood. Given the price declines, I'd suppose it would be maybe $75 today.

The same wattage lamp designed as a spot was closer to the output of a 125W incandescent. At the time halogen capsule lights were a better buy price per lumen.

We were not using the lamps outside. They were desirable because we could get the same amount of light from about 72 watts of LEDs as 1200W of halogen lamps. That saved a huge amount on HVAC costs. Because they (used) to require special transformers, and had lots of circuitry in the lamp, I would suppose exterior fixtures would need a good waterproof enclosure, and might be somewhat bulky.

The best LEDs at the time were a brand called Luxeon Star. Cree, from China, was making the fastest advances. We settled on GE. Not quite the same efficiency, but cost was about 2/3 of the others.

The big upside is that they will last decades w. ordinary use. Probably not as much as projected. The LEDs will last, but the circuits driving them will fry in maybe 20 years. Great for installation in hard to reach places, and places where continuous function is needed.

nolaegghead

Search led floods on amazon 

xfire_ATX

What Wattage HPS are you trying to replace?  

Terms
Lumens- amount of light output by the light source
footcandles- amount of light on any given surface

A fixture or lamp (bulb) gives off Lumens, the more light sources in a space/ area the higher the footcandles on any given surface.

Adding on to gdenby comments- LEDs are directional in that all light goes forward.  So 100 Watts of LED producing 85 Lumens per watt will give you appx the same footcandles on a surface as a 400W metal halide fixture.  The reason is the HID 'fixture' housing traps roughly 35-45% of the light vs an LED emits 100% of the light.

Now the great debate of Photopic vs Scotopic- that is how the light appears to the human eye.  I can go into a whole myriad of terms but basically the human eye likes the look of 4k-5k color temp that most outdoor LED products a whole lot better than the HPS~2500K so things appear brighter even though the lumens are the same.  The most efficient light source Low Pressure Sodium (used by telescopes) will make you look like a zombie.

If you are trying to replace 250W or greater you will need to look to a commercial solution vs a Home Depot Fixture.  If you want to post up a pic I can give you a few options.

Legume

I wish we knew what wattage and what type of lights, someone's digging around trying to figure that out without the going down there (~6 hours door to door)

I appreciate the info and suggestions.  Here are a couple of pics - one at night and the other is the best pic I have of one of the lights in the day

GregW

I have two of these in my back yard area,
I installed them this spring. They are excellent. 
I really like that they are instant on. They can be turned off and on at will.
They are around $130 each.
http://lighting.cree.com/products/outdoor/street-and-roadway/rul-series

U_tarded

we are replacing metal halides with induction lights in showroom.  i don't know about the use but my electrician introduced me to them.  he has done several gas stations as well.  works with magnets somehow, i am no lighting expert though.

xfire_ATX

Those CREE are nice but are going to have Glare for that application.

I would put this in RAB FFLED52 in


U Tarded- Induction is basically Fluorescent that doesnt have an end- its donut shaped.  5 years ago when LED was very expensive people started trying this again but it was only slightly less expensive.  However now that LED is competing against existing technology on a price level Induction is dead and I wouldnt use it anymore.