Lighting LED Heat Extraction

[greenjeans]

So I will be moving to LED either sometime during my current new grow, or on the next round, and I have been doing a lot of research.

I have all but decided to go with Mars. I just don't see any way to deny that they are the way to go since they seem to have great reviews and the best prices around..

Anyway, I see that the fans blow the air downward, forcing the heat out the sides of the unit. Are all (or most) LEDs designed this way? It seems really counterproductive IMO. I really can't understand why you would pull the hottest air in the space in and blow it out in such a way as to introduce heat to the space below the light. It seems backward. The heat should exit at the top of the unit.

Does anyone know why it is designed that way? I can see the fan blowing down onto the heatsink would create more turbulence inside the unit, but I also think that it would be relatively easy to create the same effect in a system that reverses the flow direction with some very minor design tweaks. I keep thinking there must be a reason, but it escapes me.

 

[oddjob]

That's point on and one of the pitfalls of going from HPS to LED, you don't have the ability to cool the hood. Best method is to prolly place fans to blow towards your carbon filter that serves as somewhat as a heat extractor.

The Mars LED seems to be very popular on these boards

 

[Chester]

I agree it seems counter intuitive but the fans on my Advanced LED lights blow the same way ... there must be a greater cooling effect when air is blown onto the fins rather than pulled over them ... I've seen a lot of great Mars grows ...

 

[robbio]

Hey chester i have 2 Advanced LEDs and one G8 led,both have the same setup.I just bought 2 BML LEDs for my seedling table,and supplement lights during Veg.I am very impressed with these,they do not have a fan.The two lights are 150 watts ,and are 36in. long.These are commercial grade lights.I,m getting to start a supersoil grow and will use for the first time ,I will let everyone know how they work.Peace.

 

[namvet25]

Blowing air on to the heat sinks and out the side is the most effiecient way to cool LED'S.They really don't give out much heat so this set up works the best.

 

[Chester]

I've been following Tangs HS1 grows on here ... he is using a ridiculous low amount of wattage and growing a jungle ... my lights will do a good job for a few more years ... by then I hope someone manages to control the heat ...



Current grow ... https://www.autoflower.org/index.php?threads/high-temps-nlbb-bubblelicious.45970/#post-862077

 

[Ozone69]

I'm running a couple of Platinum LED P150's. The fans on them blow the air up and out, sucking it in over the heat sinks through side slits. I suppose that if the fans were blowing down into the heat sink, it would possibly do more to force the air between and then out the fins on the heat sink. As it is with the air being sucked out the top on mine, it may only be flowing above the top of the fins. Seems to do a good enough job, though, as the lights aren't having any heat issues. I don't know that it would make a huge difference if the fans blew one way or the other as I just don't know that the lights are generating all that much reletive heat. The 3ft T5 side lights I've got in with them seem to raise the temp in my closet noticeably more than the LED's do, even with the LED using a little more watts.