Heatsink for 50 multichip led

[celebrityovernight]

Hey led diy gurus, can someone recommend a good heatsink for a 50 multichip led such as the dream chip. Not looking for anything over $20.

 

[kapelan]

I think heatsink a way overpraised too.
Here it is: inside old compact fixture LEDs on the aluminum bar

 

[rott]

is that an old coralife or jbj I have one like it but only 3 foot size never thought about using for leds

 

[mcgyvr]

I've got a 50W LED running on an old duron heatsink/fan out of an old computer.. works pretty darn well and you can find them for a couple bucks or sitting in a closet or whatever..

 

[ravi197699]

I have my 50w blue led running on dell heatsink I bought lot of 4 from ebay for 10 bucks and 12v fan to keep it cool and it has been working pretty good from almost 7 months....

 

[celebrityovernight]

Thanks guys, are the heatsinks handling the leds with ease?

 

[mcgyvr]

"typically" the duron heatsinks can do about 20-30 watts without the fan and 50-60 watts or so with the fan.. Now if you expect to get 50k hours then I might suggest something slightly larger as lifespan is directly related to die temperature. They are sufficient.. But obviously not the "best"

The 50W I have is running around 30-35 deg C over ambient with that Duron/Fan combo. Thats slightly warmer than I "typically" shoot for for long life.

 

[kapelan]

I'm using this fixture on the picture above about half a year.
It's 200W total, using 4 coolers (thinking to keep only 2)
It is never hot, even in the summer. Would say a bit warmer then room temperature.
Basically the rule to keep it cold is pretty simple :
Active or Passive cooler.
Passive: heatsink
Active: fan
For the best performance we are doing a combination of active+passive

 

[celebrityovernight]

Nice, I feel confident with going with some cheap Intel processessor heatsink

 

[mcgyvr]

Good choice.. A flat bar is a horrible heatsink..
Surface area of a flat bar isn't anywhere close to what you get when you throw fins on it..
Surface area is what matters..

And without having thermocouple/temperature data to back it up saying its "warm" or whatever is meaningless... There is NO way in hell I would ever create an LED fixture without doing temperature measurements on it.. I always do a 1 hour minimum temperature test. (it can take a while for "thermal stability" to be achieved)

 

[kapelan]

.. A flat bar is a horrible heatsink..

Do not forget - that's a pipe with airflow.
Increasing the led power - airflow should be increased as well.
Nothing can be overheated inside a pipe.

 

[mcgyvr]

Nothing can be overheated inside a pipe.

huh?.. Sure it can..
Don't believe the marketing crap on that Steves LED site..

Square/rectangular tube still isn't even close to the surface area a heatsink can provide..

 

[allstar.h2o]

Check out the as-is heatsinks at Rapidled. 6x10 for $10 bucks.

I have a 6x20 as-is from them and can't find any damage on it.

 

[Norahsdad]

Picked up some intel 1155 heat sink for a 30w 50w project glad some of you have had luck with them. Or that type of one with 50w