I have a BC29 and I am thinking about the BC29 heatsink you guys are selling for a LED DIY project I am putting together and have few questions. I am getting 24 XREs (50/50 wh/rb) and 60 deg optics. Originally was planning to get a Heatsinkusa heatsink which is 1.3" high, 8.46" wide and I can order it any length that will fit in the hood. From my measurements it looked like I could put a heatsink about 16" x 8.46" or so in there w/probably multiple cutouts. But, the Nanotuners h/sink looks a lot nicer, is a lot shallower and has mouting holes predrilled etc. However, it's much smaller... it's only about 11"x7" ... 1" width doesn't look significant, but the length of 11" vs the 16" that can fit there feels a bit on the low side. When looking at install pics it looks like there will be a significant (2.5") on each side gap between the h/sink and the side of the tank/hood. Assuming the cooling area is sufficient, there is still the issue of coverage... IOW, I could mount the LEDs w/a spread more uniformly across the width of the tank if the h/seink was wider, say closer to 16"s...

Questions:

1) I would like to hear the rationale for why it's ok to have a narrower mounting platform.
2) I spoke w/Chris who said there are mouting points (pre-drilled holes) for 56 stars on that h/sink. But, that's still concentrated in the 11x7 rectangle. Aren't the sides going to see a deficit of light?
3) Is the Nanotuners h/sink w/24 or so CREEs going to be OK w/just stock BC29 fans for cooling or do I need to change those out too? I've been thinking about changing them out anyway or at least adding a temp sensor in there so they only run if they need to, but don't want to be forced to do this just to make the lights work.

Thanks,

spacey

i dont know about the heat sink but with your fan question the way i see it is this. if your already gonna be taking the hood apart and are already debating swapping out the fans id say go ahead and do it while your in there because otherwise youll probably decide down the line that dang i shoulda just gone ahead and done it while i was in there. also i think the temp probe is a pretty good idea and that would be totally up to you but if it were me i wouldnt space any expense id go ahead and do the fans and temp probe for the best performance

1) We chose a narrower mounting platform for our x.6 heatsinks because we wanted to be able to use the heatsinks interchangeably & leverage our competitive advantage by offering our customers a single price for a multitude of SKUs. Stated simply, we wanted to use as few custom parts as possible.

After weeks of optimizing the thermal characteristics of the heatsink using Solidworks thermal simulation software, we were able to find that by moving the heatsink into the free stream (the heatsink stands just 1/2" tall & can still handle a thermal load ~ 140w and maintain 130F in 90F room conditions).

The one downfall of a Heatsink USA heatsink DIY retro is that the heatsink is so tall that you end up having to ventilate the top of the hood somehow. We decided to drop the heatsink into the airflow stream and cool it from both sides. BOOO YAH! no more frankenstiening your hood.

At some point, we will investigate using more of the built in light space, but for now, the "big heatsink" fits: Nanocube 12, Nanocube 24, Nanocube 28, Biocube 29, Aquapod 24, Aquapod 12 & NOW SUNPODs!!!

2. With the wide display angle of the LEDs, you should be able to get plenty of coverage.

3. The heatsink has mounting points for 2 x 80mm fans. You can tap them 4-40 and screw your fans directly in as in some of our retros. I would recommend replacing those POS oceanic OEM fans ASAP.

Take care

Chris

Chris,

Thanks for the info man, really appreciate it. That said, if you don't mind I'd like a bit more precision on few points...

2. With the wide display angle of the LEDs, you should be able to get plenty of coverage.

#2.1 - Ok, just to make sure - so you are saying that there should be enough coverage due to the XREs wide display angle, yes? Is that with or w/out the 60 deg optics?
#2.2 - Should I be thinking of not putting optics on the LEDs on the left and right side to get more coverage? But that will reduce intensity relative to the rest of the panel no? Is that still ok?
#2.3 - I got the 60deg optics because that is what I have been told directly and have deduced by reading all the DIY info here on the site, that it will maximize the intensity (which makes perfect sense). Should I not put them on at all to maximize the coverage? Basically I am trying to get my lighting to a point where I don't have to worry about not having enough of it on tap for any organizms I would ever want to put in the tank. For example a Crocea clam on the sand bed...

3. The heatsink has mounting points for 2 x 80mm fans. You can tap them 4-40 and screw your fans directly in as in some of our retros. I would recommend replacing those POS oceanic OEM fans ASAP.

#3.1 Oh really? Thats cool... but would those fit in the BC29 hood w/out mods? Where would they vent? The stock fans are I think half that size.
#3.2 Sorry, I don't know what "you can tap them 4-40" means... could you explain it to a fastener idiot?
#3.3 Agreed, w/replacing the POS fans ASAP... but... do I have to do that in order for my LED's not to fry right away? Or can I live w/them for a short time while I figure out what to do about the temp sensor and fan replacements that would run on demand.

Thanks,

spacey

2. With the wide display angle of the LEDs, you should be able to get plenty of coverage.

#2.1 - Ok, just to make sure - so you are saying that there should be enough coverage due to the XREs wide display angle, yes? Is that with or w/out the 60 deg optics?
- once the light hits the water, it bends away from the normal, so it will spread out on its own due to the different index of refraction the water/air interface (snells law).

#2.2 - Should I be thinking of not putting optics on the LEDs on the left and right side to get more coverage? But that will reduce intensity relative to the rest of the panel no? Is that still ok?
- The main drawback of optics in a BC 29 or any all in one is the spotlight effect that can occur with too tight of optics. We run most of our systems without optics because of this fact, and give up high par for coverage. With optics, you will see 400-500 par on the sandbed depending on optics. Without, you will see 100 or so.

#2.3 - I got the 60deg optics because that is what I have been told directly and have deduced by reading all the DIY info here on the site, that it will maximize the intensity (which makes perfect sense). Should I not put them on at all to maximize the coverage? Basically I am trying to get my lighting to a point where I don't have to worry about not having enough of it on tap for any organizms I would ever want to put in the tank. For example a Crocea clam on the sand bed...
- Par of 400 or 100 will get the job done. Its about dealing with the potential spotlighting.

3. The heatsink has mounting points for 2 x 80mm fans. You can tap them 4-40 and screw your fans directly in as in some of our retros. I would recommend replacing those POS oceanic OEM fans ASAP.

#3.1 Oh really? Thats cool... but would those fit in the BC29 hood w/out mods? Where would they vent? The stock fans are I think half that size.
- Convective cooling says that as long as you have airflow, and a temperature gradient, you will have cooling. The 80mm fans get mounted on top of the heatsink (with some spacers). The venting of the air into/out of the canopy is done by the fans in teh BC29 hood (unfortunately 1 in 1 out). This will be sufficient to keep the heatsink at 130F or lower with a load as high as 140W. This is still way below the 50C LEDs are nominally rated at.

#3.2 Sorry, I don't know what "you can tap them 4-40" means... could you explain it to a fastener idiot?
On the top of the heatsink, we have 8 holes which are untapped. You can tap them to accept a 4-40 machine screw.

#3.3 Agreed, w/replacing the POS fans ASAP... but... do I have to do that in order for my LED's not to fry right away? Or can I live w/them for a short time while I figure out what to do about the temp sensor and fan replacements that would run on demand.
- I would get the quietest fans you can find and run the fans all the time. The temp sensor would be nice, but not necessary. Just keep enough air coming into and out of the canopy and the 80mm fans on the top of the heatsink going and you will be fine.

Not to go off subject or hijack the thread or ntohing But i have got to say..

I love seeing so many sponsors on this forum. I think its a great service to your customers/potential customers as well as a credit to your committment to your products and hobby.. so Thank you to all the sponsors and other merchants who post their support on this forum..

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