[nokturnalkid]

I have a diy led fixture that I'm just about done with. The heatsink is made from aluminum L angle bar. There is maybe a 1/4" gap in between each bar. The fixture is in a open top canopy built just to fit the heatsink. Which way should I have the airflow. The fan sits above the heatsink blowing up. Would this e the best way to face the fan? Or, should I turn the fan so its blowing down onto the heatsink? Mot sure which is the best way to do this.

Thanks in advance...

 

[majorwoo]

You want the fan to blow away from the heatsink - it should pull the air in/over the fins of the heatsink and blow it out and away. So you have it right.

 

[Gecko]

If your fan compeletely cover whole heatsink you can put it as "sucking hot air from heatsink and blow away" style.

But if your fan is smaller than heatsink (usually it is) you must run opposite side. take the cool air and blow to the heatsink fins. By the way blow away hot air between fins.

Its my opinion... you can try two diferent way..