Easy money saving with LEDs

JohnB47

LowEnergySupporter wrote: »

I work for myself. Replacing 50W halogen lights with 3W LEDs may be good for the environment but not so good for your lighting. A 50W halogen spot has about 500lm which is better replaced with a 6W or 7W LED. 10 good 6W LEDs will cost you about 40-50£. Please take also a look at the energy rating, A++ is the best you can get at the moment. Most people also prefer the warm-white version. If you find the letters "2700K" on the product, then you are right.

Fair enought, that's good advice. Although you haven't mentioned CRI, which is an important measure of the quality of light. High CRI is best, certainly over 80. If no CRI is quoted, I would avoid. Another factor is a good return policy - people really need to try these things out and be able to return them if they're not happy.

Also, 40 -50 £ for 10 6w leds still seems too cheap to me. More like 90-120£ for good quality and a long guarantee - at least 3 years (from someone who is going to be around to honour it). Prices are coming down of course.

almillar

Your sums are a bit off LowEnergySupporter but you're on the right track.
A 50w halogen will give out about 800 lumens - not 500, but it's not quite directly comparable to LED - 500+ lumens, with the same beam angle and a good CRI, is a good replacement.
Which LED did you use in your comparison - a 12W one that replaces 100W? I'm interested!
Totally correct about colour temp - 2700K is 'warm white' - 3000K, often called warm white, is actually significantly 'whiter' and 'colder'.

LowEnergySupporter

Thanks for your feedback. I must admit that i was not aware of the cri indicator.. until now.

The 12W-100W is just an example. Not everyone has an degree in optics or electronics, and most people are still comparing the watts not the lumens or the cri value. That is why i wanted to keep things as easy as possible.
I figured out that most LEDs will consume about 1/8 of the energy compared to filament bulbs. That is why i used this example.
Currently i am building a homepage around this topic and i am thankful for every tip i get.


At home i replaced 6 x 50Watt GU 10 Halogens with 6 x 4Watt A++ LEDs at 2700K in the bathroom. Subjectively i would say the light has the same brightness and feels a little bit warmer.

The kitchen and floor are lighted with a 9W E27 2700K LED bulb which is comparable with an old 75W bulb, i think.

And i recently bought a A++ 4W E27 Filament LED Bulb, this thing really looks like older bulbs and I think this kind of LED will be accepted by most people as soon as they are available at a higher wattage. This bulb doesn't even get hot, you can touch it while it is on ... that's kind of strange because it really looks like an older bulb.

almillar

I figured out that most LEDs will consume about 1/8 of the energy compared to filament bulbs. That is why i used this example.

Bad assumption, and these are all over the place. It's very easy to tell how much they use - it should be quoted in watts. There's no point in doing these energy and money saving comparisons unless you're comparing the bulb coming out against the bulb going in.

Not everyone has an degree in optics or electronics

Me neither. All I ask is that you use a measurement of light (lumens, candela), to measure light, instead of a measurement of energy (watts).

6 x 50Watt GU 10 Halogens with 6 x 4Watt A++ LEDs at 2700K

So you're using 24 watts instead of 300. Great. What LUMENS are they?!

elstimpo

JohnB47 wrote: »

High CRI is best, certainly over 80. If no CRI is quoted, I would avoid. .

Most Retailers avoid stating CRI because they know their products fall well short of halogen and incandescent levels even though they advertise them as 'perfect' 'genuine' and 'like for like' replacements. I'm afraid thats pure marketing nonsense.

High CRI is also not 80, thats average, to properly replace an incandescent and halogen you need CRI within 5% of the halogen and incandescents figures which means CRI of 95+ , which you can find in LED's now.

A colour temp of 2700k, CRI of 95 or more and the required lumens to suit the application is needed to genuinely replace the feel, light quality and ambience created by halogens and incandescents.

Which actually means that virtually every LED Lamp on sale anywhere in the world is NOT a true replacement for traditional lamps.

This industry is full of companies manipulating consumers in order to sell products and it's an utter disgrace. Watch out for 5 year warranties that are actually only 2 year warranties. Seems to be the trendy thing to advertise at the moment.

Needs regulation and quick.

elstimpo

almillar wrote: »

Your sums are a bit off LowEnergySupporter but you're on the right track.
A 50w halogen will give out about 800 lumens - not 500, but it's not quite directly comparable to LED - 500+ lumens, with the same beam angle and a good CRI, is a good replacement.
Which LED did you use in your comparison - a 12W one that replaces 100W? I'm interested!
Totally correct about colour temp - 2700K is 'warm white' - 3000K, often called warm white, is actually significantly 'whiter' and 'colder'.

Actually with CRI of 95 or above you can replace a 50w halogen with around 350 lumens. Low CRI product (around 80) need more lumens.

It's important to note that not all 50w halogens produce the same lumens.

elstimpo

JohnB47 wrote: »

Fair enought, that's good advice. Although you haven't mentioned CRI, which is an important measure of the quality of light. High CRI is best, certainly over 80. If no CRI is quoted, I would avoid. Another factor is a good return policy - people really need to try these things out and be able to return them if they're not happy.

Also, 40 -50 £ for 10 6w leds still seems too cheap to me. More like 90-120£ for good quality and a long guarantee - at least 3 years (from someone who is going to be around to honour it). Prices are coming down of course.

Prices are coming down, but very quickly on the tat and not so quickly on the quality. I was offered a 5w LED Spot, 3000k, 450 lumens and 50,000 hour lifespan for $2 at the Hong Kong lighting show in October.

When i asked them what quality LED Chip, LED Driver and power supply could possibly be fitted into a product that costs $2, how much they were paying their staff and how it could possibly last 50,000 hours - i was ushered away. :rotfl:

Oh and this product is currently on sale in the UK :mad: