How do I use LEDs to replace fluorescent lamps?

ruriimasu

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Oct 17, 2007
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566
(not sure if this is the correct thread to post)

Hi all,
I am using those circular fluorescent lamp tubes in my living room and the voltage here is 220V-250V. How can I use Cree LEDs to replace them? I am thinking the advantage of doing this will be cheaper electricity bill, long lasting LEDs that dont really require replacement, brighter, and last but not least.. its cool! imagine having 2-4 tiny LEDs providing such massive amount of light :D :crackup:

if anyone knows what parts i can get from DX to build this light, i'll be very happy :D
 

Oznog

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Dec 2, 2006
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595
Well, realistically it won't be significantly less on your electric bill, and the LEDs will be VERY expensive. Also they won't last forever either. If it's a cheap ballast or heatsink, then there's a chance of premature death.

LEDs are only slightly more efficient than CFL. CFL only costs like a few dollars a year to run anyways. The big gain is going from incan to CFL or LED. CFL to LED is not a significant difference and it's already too low to even care about lowering further.

A Cree is like 100 lumens unless you're overdriving it (in which case it's less efficient and will not last quite as long). A 20W CFL might put out 1200 lumens. So you need 12 Crees. You will need a well designed heatsink. You will need some sort of light diffuser or reflector because those things are way too intense point sources to just shine downward. Even if the room lighting level is not exceptionally high, you look up at those things and you'll be blinded.

If you're doing this, do it because it's "cool", don't expect it to be cheaper or more convenient. And that IS cool.
Also, LED can be dimmed IF your ballast supports it. CFL cannot be really be dimmed, technically some claim to be able to but their dimming range is limited and I'm fairly sure it really messes with the CFL tube to do that.

KaiDomain or DX carries ballasts, but they're definitely likely to be the "cheap" ones though. Might work fine. The thing to worry about is also flicker, a 50Hz flicker would really annoy you over time. There is no way you should be doing a DIY circuit with 220V ballast BTW. Don't. There is no easy amateur solution and you'll probably start a fire sooner or later.
 

I'mIn

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Dec 19, 2008
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Also a living room will need lots of ambient light which is not where LED's outshine Fluoro's. A reading light, for example, where concentrated and conserved light may be more important is a good place to use LEDs. This is somewhat counterproductive financially, because the less the light is used(such as our readinglamp),the less important the wattage it consumes, and therefore the less energy savings it will provide you.
Like he said above it's cool, but maybe the cost of cool isn't what you were looking for.
 

holiday light express

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Dec 16, 2008
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64
Location
Ann Arbor
Right now LED bulbs are pretty application specific. For example, they don't break, so they are great for garage door open lights or lamp lights.
They are great for reading lights that collectors use. They don't get as hot, they don't give off UV, they are available with "true" white lights.

But I would agree, that lighting your hole house with LED bulbs, even the real nice ones would be a little expensive.
 

Ken_McE

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Jun 16, 2003
Messages
1,684
There is something called the VOSpad which is an entire apartment in London lit solely by RGB LEDs. The result is beautiful but cost around $50,000 US to install. Some of that would be the cost of embedding things in the walls and floor, and running wires everywhere.

Manufacturers site:

http://www.thevospad.com/projects/the_vos_pad/the_vos_pad_main.htm

Better pics:

http://www.globefox.com/vospad/gallery.html

Bit of history on who did it and how it came to pass:

http://www.archlighting.com/industry-news.asp?sectionID=1335&articleID=453495

If you feel ambitious you could do something like this on a more modest scale for your basement. No CFL could possibly come near the cool factor.
 

blasterman

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Jul 17, 2008
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1,802
I run CFL's in my lamps at home, and agree there's no practical way to replace a 1,000 lumen, 3500k with LED without costing a fortune. Lumen value is one thing, but one thing that hasn't been mentioned is that the warmer and more aethestic color values that are easy to supply with CFL are still a secondary consideration with LED.

If you prefer sterile, neutral white or cool light in your living room we seriously have different tastes.

On the other hand, there's no reason an average size living room can't be lit with a couple decent lamps. Having dozens of can/recessed lights isn't a problem for LED to solve.
 

blasterman

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Messages
1,802
I know to some people it doesn't matter, but those retrofits have a CRI of 75. $80 buys you about +1,000 lumens of decent Cree or Seoul emitters, and the color quality along with durability will be drastically better.

No CFL could possibly come near the cool factor.

I couldn't hold a Miami Vice fan club convention either, but I'm not bragging about it ;)

Where's the faux tiger skin rug on the wall, eh?
 

LukeA

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Joined
Jun 3, 2007
Messages
4,401
Location
near Pittsburgh
Well, realistically it won't be significantly less on your electric bill, and the LEDs will be VERY expensive. Also they won't last forever either. If it's a cheap ballast or heatsink, then there's a chance of premature death.

LEDs are only slightly more efficient than CFL. CFL only costs like a few dollars a year to run anyways. The big gain is going from incan to CFL or LED. CFL to LED is not a significant difference and it's already too low to even care about lowering further.

A Cree is like 100 lumens unless you're overdriving it (in which case it's less efficient and will not last quite as long). A 20W CFL might put out 1200 lumens. So you need 12 Crees. You will need a well designed heatsink. You will need some sort of light diffuser or reflector because those things are way too intense point sources to just shine downward. Even if the room lighting level is not exceptionally high, you look up at those things and you'll be blinded.

If you're doing this, do it because it's "cool", don't expect it to be cheaper or more convenient. And that IS cool.
Also, LED can be dimmed IF your ballast supports it. CFL cannot be really be dimmed, technically some claim to be able to but their dimming range is limited and I'm fairly sure it really messes with the CFL tube to do that.

KaiDomain or DX carries ballasts, but they're definitely likely to be the "cheap" ones though. Might work fine. The thing to worry about is also flicker, a 50Hz flicker would really annoy you over time. There is no way you should be doing a DIY circuit with 220V ballast BTW. Don't. There is no easy amateur solution and you'll probably start a fire sooner or later.

I made a spreadsheet a while back about this. You might find it enlightening, so to speak.

EDIT: I just realized that I deleted some important data from the spreadsheet, namely the data for the LED fixture lifecycle.

The data should be as follows:

0 0
0 98.99
50000 218.99
 
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