Lighting Confused over Meanwell specs

[Jimmyclone]

I was quoted 13$US on alibaba for 160mm pin fin passives.. Which to me is a pretty good deal.. I payed 18$ for 140mm from rapidled.. I personally prefer passive, as i regularly spend a couple days away from the tent and would always be worried about those fans.. Though i assume you can buy higher quality fans somewhere.. Ether way buddy, keep those cobs cool and they will last u a long time..
Cheers

 

[pop22]

Not all heatsinks are equal..... nor do they dissipate heat equally well. I'd be very careful buying, cheap, Chinese heatsinks. Thermal resistance goes up as the grade of Aluminum goes down. Die casting is even higher C/W than forged or extruded Al, and the Chinese sometimes polish die-cast material so that it looks like higher grade Al. They've been known to even go so low as the use zinc and pass it off as aluminum ( Be VERY careful about cheap, Chinese herb grinders, many are NOT aluminum, and ingesting/inhaling Zinc can be bad for you!) IMO, py a little more for name brand and KNOW what your getting!

I was quoted 13$US on alibaba for 160mm pin fin passives.. Which to me is a pretty good deal.. I payed 18$ for 140mm from rapidled.. I personally prefer passive, as i regularly spend a couple days away from the tent and would always be worried about those fans.. Though i assume you can buy higher quality fans somewhere.. Ether way buddy, keep those cobs cool and they will last u a long time..
Cheers

 

[L0wbob2017]

Be sure on getting some quality heatsinks!
I once had a heatsink with 2 COB's in series mounted on it. One side cooled like it should, the other one had some unknown issue and the COB just went to hell.
Because they where connected in series ( god thanks for this ) the other COB turned off too. ( both were running at close to their max values for testing reasons ).

 

[Bekay]

These are the heatsinks I ordered.

If they do indeed handle 50W of heat and I am running them at ~75W any efficacy (efficiency?) over 33% would produce less than 50W heat. I think I am safe there. If I grasp the Thermal Resistance concept (doubtful, but maybe) 75W x 0.85 C/W = 64 degrees C increase if all went the watts to heat. If only 50W of the 75W went to heat the rise would be 43 degrees C. Add that to the ambient of 25C and it would be 68C in still air, which it won't be with fans in the tent and a 6" exhaust fan. Still well below the 85C reference temp in the COB data sheet.
I played with light distribution diagrams today and decided the 90 degree Angelina's were of no benefit in my small tent. I will include those in my build thread. Looks like 300W of COB power for $310 shipped plus $20 est for L channel aluminum frame.

 

[Jimmyclone]

Those will work just fine..
Good luck on the build

 

[pop22]

You've got it right. and probably 43%+ efficiency if its a good, brand name chip like Citizen or Cree. Optics are not needed in a tent, the reflectivity makes them unnecessary.

These are the heatsinks I ordered.
View attachment 757770 View attachment 757771
If they do indeed handle 50W of heat and I am running them at ~75W any efficacy (efficiency?) over 33% would produce less than 50W heat. I think I am safe there. If I grasp the Thermal Resistance concept (doubtful, but maybe) 75W x 0.85 C/W = 64 degrees C increase if all went the watts to heat. If only 50W of the 75W went to heat the rise would be 43 degrees C. Add that to the ambient of 25C and it would be 68C in still air, which it won't be with fans in the tent and a 6" exhaust fan. Still well below the 85C reference temp in the COB data sheet.
I played with light distribution diagrams today and decided the 90 degree Angelina's were of no benefit in my small tent. I will include those in my build thread. Looks like 300W of COB power for $310 shipped plus $20 est for L channel aluminum frame.

 

[L0wbob2017]

These are the heatsinks I ordered.
View attachment 757770 View attachment 757771
If they do indeed handle 50W of heat and I am running them at ~75W any efficacy (efficiency?) over 33% would produce less than 50W heat. I think I am safe there. If I grasp the Thermal Resistance concept (doubtful, but maybe) 75W x 0.85 C/W = 64 degrees C increase if all went the watts to heat. If only 50W of the 75W went to heat the rise would be 43 degrees C. Add that to the ambient of 25C and it would be 68C in still air, which it won't be with fans in the tent and a 6" exhaust fan. Still well below the 85C reference temp in the COB data sheet.
I played with light distribution diagrams today and decided the 90 degree Angelina's were of no benefit in my small tent. I will include those in my build thread. Looks like 300W of COB power for $310 shipped plus $20 est for L channel aluminum frame.

these will just work fine. also if you think about the air circulation in your room you may end up with slightly lower temps than expected.

you could also go nuts on cooling like i did and which could be viewed in my "DIY clickbait" in the signature

 

[Bekay]

I did check "DIY Clickbait" last night. Inspirational my friend.

 

[wwwillie]

Hey!
So, how's the project coming along?

 

[Bekay]

I'm commencing to begin to get ready to start in a week or so.
Procrastination is highly underrated, I find.
Picked up the Alum. angle iron 1/16 x 3/4 last trip to the city. Lowes had it in 8 ft length for $16.