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Coral Vue Hydros

How much heatsink


HM3105

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Hey Dave,

 

I got my V3 array firing and it looks great but I'm having some heat issues. I've got it on a 2" by 4" actively cooled (with a 40mm fan) heat sink and the temparature is rising to around 200 F after 30 minutes.

 

How big of a heat sink do I need to cool these assuming active cooling?

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Way too small. General rule of thumb is 10in^2 of surface area per watt for passive cooling (no fan), and 3in^2 per watt for active cooling with a moderate flow rate.

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jedimasterben

That's quickly approaching where I would consider the violets to start having issues with longevity. You're pushing all channels at 700mA? Is this at maximum output? Is the fan at full speed? What did you use to attach the PCB to the heatsink, is it making good contact?

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What type of fan? I push the limits on mine as well however not anything close to this. Is the heatsink just sitting on top? Enclosed? Is it blowing through the fins or pulling?

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That's quickly approaching where I would consider the violets to start having issues with longevity. You're pushing all channels at 700mA? Is this at maximum output? Is the fan at full speed? What did you use to attach the PCB to the heatsink, is it making good contact?

 

Right its way too hot, I'm not actually running it over a tank. I was testing it to see if the heat would dissapate (which it isn't). So I turned it on for 30 minutes and measured the temp, saw it go to 200 and turned it off. All the channels are set at 50% using 700mA LDDs. The fan is at full speed as far as I know, it doesn't have a controller just plug it into a wall wart. The PCB is attached to the heatsink at the edges with screws with nylon washers, I used thermal paste in between (cermique 2 I believe) the PCB and the heat sink.

 

What type of fan? I push the limits on mine as well however not anything close to this. Is the heatsink just sitting on top? Enclosed? Is it blowing through the fins or pulling?

 

This fan - http://www.amazon.com/Scythe-Mini-KAZE-Silent-SY124010L/dp/B000LB0M8S/ref=sr_1_3?ie=UTF8&qid=1441041946&sr=8-3&keywords=40mm+fan&pebp=1441041715693&perid=1XTGWRYZWABD5SM1D34X

 

The heat sink is partially enclosed in a metal project box with two 1" holes on the top. One of the holes is directly over the fan which is blowing on the heat sink. The other is directly over the heatsink. The acrylic cover has a 1/8" gap between it and the enclosure edges also to help ventilate the heat.

 

Evil is probably right, I just need to order a bigger heatsink..

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Can we get a look at the heatsink you used?

 

Also, 200F is still within tolerance of the LEDs, but if you got that at only 50% output, then you are going to make matters worse no matter what you do to try and improve the current situation. You really need a bigger heatsink. A larger diameter fan wouldn't hurt either if you have the room.

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Can we get a look at the heatsink you used?

 

Also, 200F is still within tolerance of the LEDs, but if you got that at only 50% output, then you are going to make matters worse no matter what you do to try and improve the current situation. You really need a bigger heatsink. A larger diameter fan wouldn't hurt either if you have the room.

 

I'm fairly certain my heat sink is too small at this point, I had no idea these things for this hot! I'll just need to get another one. Maybe Dave will sell me a blank like the one he uses for the mini........

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jedimasterben

 

I'm fairly certain my heat sink is too small at this point, I had no idea these things for this hot! I'll just need to get another one. Maybe Dave will sell me a blank like the one he uses for the mini........

The heatsinks in the Mini are roughly the same size.

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