Temp on heatsinks? Diy cob led

Hello.

Ive made my grow lights, inspired from a member here.

Im rubbing 5x Vero 18s @0.5A, aprox 15w per light. Cooling them I use Arctic 11, but passive. How hot is it acceptablw for the heatsinks to get?

After about 30min they feel warm, however not really hot. It doesnt hurt, but its only been running a short way without any circulation in the tent.

Will circulation be enough or should I add some fans blowing across the "board"?

Question 2 - is there any max distance I should go for? I only feel the heat from the lights up to 20-25cm, however I dont know if thats an indicator.

Thanks again for the help Ive gotten, or it wouldnt have been a light.

Will post more pics of the dit equipment if someone is interested later.

You need exhaust of the entire tent. Not just blowing on them. That'd how you get temp down. I'm glad I went for large extruded heatsinks rather than cpus like I planned originally. At full brightness, my heatsinks stay straight up COLD.

There is an exhaust, just not visible. Upright corner.

Unfortunatly I couldnt get my hands on a nice big one.