LED lighting

[charles123]

I am thinking of replacing a couple of my 10 watt halogen downlighters with LED fittings since they are getting more cost effective.

 

I know they use less power which has to be good and last mant times longer than conventional bulbs but does anyone know what the light output is

 

Eg I have seen fittings with 6 LED and other fittings with 12 LED. Anyone know what the equivalent would be in watts ie would these represent the same light output of a 10 watt bulb or 20 watt bulb etc?

 

Charles

[DHutch]

I did some research on LED lights a few months back (maybe a year now)

 

There acttually not great for room lighting.

- Infact, in terms of lumens per watt, there not that much better than a dence halogen. And there considerably worse than a fluorencent.

 

And there not great at producing white light. (also of the "white" leds are made using florecent coatings)

 

There great for torches etc, where the blueish light is actually good, becuase we more receptive to that in low levals. And becuase they actaully get more effenect as the voltage decrease (ie battery going flat) unlike incandesents.

- And also also great in street lights, becuase there very durable and long lasting, and can produce the colours directly, rather than wasting loads of it by pasing it thought a coloured gel.

 

So if your looking for low-power room lighting on your boat, florenents are the way to go.

- LEDs are good for low-leval lighting, such as outside to loo at night, but they wont make great replacements for you downlighters.

 

 

Daniel

[Richard Bustens]

What Dan says is corect but if you can accomadate them, 500 in the celing panel uses about 12 w @ 24v and is very efective for room lighting.brighter than a 60w light bulb.

 

Though you will have to hang on till xmas for B&Q to get more stocks in they come in 120 chaines and if you do away with the controler they work on 24v.

Edited March 11, 2006 by Richard Bustens

[charles123]

What Dan says is corect but if you can accomadate them, 500 in the celing panel uses about 12 w @ 24v and is very efective for room lighting.brighter than a 60w light bulb.

 

Though you will have to hang on till xmas for B&Q to get more stocks in they come in 120 chaines and if you do away with the controler they work on 24v.

 

 

Having done a bit more checking I can get a G4 (this is the standard quartz halogen downlighter bulb) replacement in LED for about £8 containing 20 LED and I believe its equivalent to a 25 watt bulb, the amperage will be 10% of the quartz halogen which is a massive saving and will run between 11 and 15 volts.

 

It apears that the thing to watch for is the number of LED you are getting in your fitting or bulb, many of the decking light fittings that appear quite cheap have only 6 LED

 

You just have to be a bit carefull when comparing light output of various types of bulbs eg flourescent v tungsten etc as they give out a light in all directions or a focused light if you follow me. I guess the thing to do is spend the £8 and buy one and report back which is what I will do

 

http://www.leisurepower.co.uk/acatalog/21_..._volt_lamp.html

 

Charles

[bottle]

"21 LED < 2watt 12 Volt equivilent 15 watt"

 

This is a comparison of power consumtion and not the amount of light output.

 

Light ouput is measured in lumens.

[DHutch]

"21 LED < 2watt 12 Volt equivilent 15 watt"

This is a comparison of power consumtion and not the amount of light output.

I beleave is trying to say the light out put of the 2watt LED cluster in compairable to that of a 15w Incadecent (halogen?) lamp.

- Like 240v CFL's have "equivelent to a 60w bulb" on the side of the box

 

 

Daniel

[bottle]

I beleave is trying to say the light out put of the 2watt LED cluster in compairable to that of a 15w Incadecent (halogen?) lamp.

- Like 240v CFL's have "equivelent to a 60w bulb" on the side of the box

 

 

Daniel

 

Daniel

 

I'm sure you are correct

[John Orentas]

There isn't a straight comparison to be made between filament lamps and L E D's. All filament lamps radiate in roughly all directions, to have some control over them you must use some form of reflector or diffuser, if they are for area lighting such as the cabin of a boat the 'all round radiation' is a positive advantage.

 

An L E D by definition will radiate light in a limited direction or divergence so true comparisons can't be made. If you are designing a feature light or a hand held torch, one or more L E D would be a good device/s to use as most of it's output can be used.

 

Also by definition when using a filament lamp a theoretical maximum of no more than 50% can be controlled by reflector or prism.

 

There has been some confusion. A tungsten lamp is very different from a tungsten halogen, we should not confuse the two.

[Alastair]

 

So if your looking for low-power room lighting on your boat, florenents are the way to go.

- LEDs are good for low-leval lighting, such as outside to loo at night, but they wont make great replacements for you downlighters.

Daniel

 

Sorry, daniel, you are wrong.

 

I have used LED, Halogen and fluor tubes. The output varies hugely. The 1W bike light I have gives off a great deal more light than the 8W 12V fluor - point the bike light at the ceiling, and the reflected light totally drowns out the fluoro

 

That said, the LED downlighters use low output LEDs generally. They are ok as reading lights, or to light a specific spot such as a cooker, but not for room lighting.

 

I have found that Halogens are best for this. A couple of 5W halogen bulbs, suitably placed, will do a better job of lighting a room than a couple of 12V 8W fluoro. Yes, the Fluoro give off more light than the halogen, for the same wattage. However, the colouring of the halogen light seems to make it more usable to the human eye. So you can get away with lower wattage halogen.

[John Orentas]

Quote;

 

"The 1W bike light I have gives off a great deal more light than the 8W 12V fluor".

 

First, what is a 'bike light', but whatever it is it won't be 8 times more efficient than a fluorescent tube.

[Alastair]

A 'bike light' is a light used on a bicycle,

 

I have no way to measure the amount of light given off other than my eyes - and by that measure, the bike light gives off much, much more light than the fluoro.

[Guest]

A 'bike light' is a light used on a bicycle,

 

I have no way to measure the amount of light given off other than my eyes - and by that measure, the bike light gives off much, much more light than the fluoro.

Are these the blue coloured led type bike lights? If they are I know what you mean. The led lights on my son's bike are superb (2 blue leds-one reflector), and the battery life is nothing short of amazing.

[Alastair]

No, they are absolutely white.

 

Very expensive - normally £50, I got mine for £25 from ebay.

 

I have several LED bike lights, and these cateye ones are very very bright. If I leave them on the high setting, oncoming cars tend to flash their headlights at me - they are that bright.

[ChrisPy]

I have read that the lighting industry will dramatically change over the next 10 years, and LEDs will become the norm. A bit like CDs replacing VCRs.

[Richard Bustens]

These things are improving all the time, but at the minuite i think you need about 100 to be anything like a 10w bulb but i expect they would be a lot better with a reflector of some sorts behind,

 

But the power consumption is still a lot less even with 500 and they look good i driled 500 holes in a sheet of 4mm ply and poked them through from the back and fitted it as a removable panel in case i did not like it, the jury is still out on that as although i like them im'e not convinced they go with the theme.

[charles123]

These things are improving all the time, but at the minuite i think you need about 100 to be anything like a 10w bulb but i expect they would be a lot better with a reflector of some sorts behind,

 

But the power consumption is still a lot less even with 500 and they look good i driled 500 holes in a sheet of 4mm ply and poked them through from the back and fitted it as a removable panel in case i did not like it, the jury is still out on that as although i like them im'e not convinced they go with the theme.

 

 

with 500 you must need sunglasses on to sit in that room, seriously I am still not understanding how many LED you need for an equivalent size conventional light bulb. Although it has been pointed out that light is measeured in lumens we dont go down to Tesco and ask for "a 200 lumen light bulb please"

 

Charles

[Richard Bustens]

No. 500 is acceptable but nothing like as light as the bathroom, same kind of size but with 9 x 10w halogen bulbs in fact not even 1/2 as much light. but i only put them in for effect. there will also be 2 wall lights and a big centeral fitting in tiffany glass these defuse a lot of the light out so also are not that bright.. so there will be 3 diferent light sources for diferent moods and diferent uses for the room.

[ChrisPy]

.... the bathroom, same kind of size but with 9 x 10w halogen bulbs

90watts of light in a small bathroom on a boat is an awful lot of power, and if they are halogens it will be lit up like a filmset, methinks. What do you plan to do in there?

[Richard Bustens]

Need bright lights as if not the shadows make the wrinkles and bags under eyes look verrrrrrrrry bad anyway i made a mistake there are only 8 not 9

[Jim Riley]

48 led replacements

£3.98 + £9 p+p on ebay

[Alastair]

48 led replacements

£3.98 + £9 p+p on ebay

 

I've made several lights up from cheap LEDs bought from Ebay. All of them expired after a while, and were not particularly bright.

[charles123]

I bought one of these £8 replacement lamps for a G4 fitting downlighter and all the responses to this posting advising doubts about the light output from LED were correct.

I fitted the LED bulb and would estimate that its output is less than a 10w halogen bulb. This one contained 20 LED.

This is disapointing so I will not be buying any more nor can I recommend these to anyone because of the poor light output.

It wont be wasted however as I have an under deck light that is not a downlighter which lights the front stairs and will therefore be on much of the time during evenings, the massive saving in power used by the LED will be an advantage

 

Charles

[John Orentas]

Charles

 

Out of curiosity what is the wattage rating of the LED unit, it is possible to buy G4 tungsten halogen lamps as small as 5 watts.

[charles123]

Charles

 

Out of curiosity what is the wattage rating of the LED unit, it is possible to buy G4 tungsten halogen lamps as small as 5 watts.

 

John,

 

These units are not rated in terms of wattage, I guess that was what I was trying to establish in the first place, my guess is they are equivalent to about 5 or 6 watts.

As regards halogen units or 5 watt, I have not seen them advertised anywhere

 

Charles

[DHutch]

These units are not rated in terms of wattage.

Yeah, ive noticed that.

- Do you have a multimeter? It would be really great if you could mesure what is drawing at what voltage (watts=amps*volts)

 

 

Daniel