How do I use LEDs to replace fluorescent lamps?

ruriimasu · Jan 4, 2009

(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

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

Oznog · Jan 4, 2009

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.

ruriimasu · Jan 5, 2009

oh i see.. i thought it would be easy. thanks for the advice

I'mIn · Jan 5, 2009

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 · Jan 5, 2009

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 · Jan 5, 2009

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 · Jan 5, 2009

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.

Power_of_the_Sun · Feb 10, 2009

Anyone checked out these to replace fluorescent lights?
http://www.earthled.com/DirectLED-t8-fluorescent-led-tube-replacement.html
1500 lumens out of 15W 4ft fluorescent bulb replacement
2400 lumens out of 24W 6ft fluorescent bulb replacement

Downsides are price ($80 per 4ft replacement bulb) and the need for re-wiring or the purchase of an EarthLED replacement fixture.

blasterman · Feb 11, 2009

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 · Feb 11, 2009

Oznog said:
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

Ken_McE · Feb 11, 2009

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

What do I click to convince it to give me the file??:thinking:

LukeA · Feb 11, 2009

Ken_McE said:
What do I click to convince it to give me the file??:thinking:

Enter the 3 digit captcha and in 45 seconds the download link will appear.

Alternatively, PM me your email and I will send you the file.

How do I use LEDs to replace fluorescent lamps?

ruriimasu

Enlightened

Oznog

Enlightened

ruriimasu

Enlightened

I'mIn

Newly Enlightened

holiday light express

Newly Enlightened

Ken_McE

Flashlight Enthusiast

blasterman

Flashlight Enthusiast

Power_of_the_Sun

Newly Enlightened

blasterman

Flashlight Enthusiast

LukeA

Flashlight Enthusiast

Ken_McE

Flashlight Enthusiast

LukeA

Flashlight Enthusiast

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