Reef Discussion
Home work done, (kinda):)
Each heat sink will be 1.49m in length, 98mm wide and 33mm in height. Cooling fins are 8mm apart and 25mm high, made from extruded aluminum
The heat sink has a thermal resistance of 1.49C/W per 200mm length convection cooled.
There will be four runs the width of the tank, spacing is yet to be decided and we will be using a number of fans per length.
OK, 20 Question's time! cool! and no I'm not in training to be a policeman.
How do I work out how many 3W Cree's I can use on each length? (considering the use of a few XM-L Cree's also)
What spacing should be centre to centre of each star on a grid?
On 2.5Ft deep tank, what lenses would suit? 80 deg - 65deg - 55deg or a mixture?
As there will be a total of 8x 1.49m length's, will 1x ELN-60-48D be enough to power 2x length's running ??? many 3W @800ma?
also 1x ELN-60-48D be enough to power 2x lengths running the blue's?
We already have 8x ELN-60-48D, just wondering if we need more :)
LED's waiting on number's to order as follows.....
CREE XP-E Blue 3W LED with 55 degree White Lens
CREE XP-E Royal Blue 3W LED with 55 degree White Lens
CREE XP-G Neutral White 3W LED with 65 degree White Lens
CREE XP-G R5 Cool White 3W LED with 65 degree White Lens
CREE XM-L T6 3W LED on star (cool white)
Umm did I miss anything?
Each heat sink will be 1.49m in length, 98mm wide and 33mm in height. Cooling fins are 8mm apart and 25mm high, made from extruded aluminum
The heat sink has a thermal resistance of 1.49C/W per 200mm length convection cooled.
There will be four runs the width of the tank, spacing is yet to be decided and we will be using a number of fans per length.
OK, 20 Question's time! cool! and no I'm not in training to be a policeman.
How do I work out how many 3W Cree's I can use on each length? (considering the use of a few XM-L Cree's also)
What spacing should be centre to centre of each star on a grid?
On 2.5Ft deep tank, what lenses would suit? 80 deg - 65deg - 55deg or a mixture?
As there will be a total of 8x 1.49m length's, will 1x ELN-60-48D be enough to power 2x length's running ??? many 3W @800ma?
also 1x ELN-60-48D be enough to power 2x lengths running the blue's?
We already have 8x ELN-60-48D, just wondering if we need more :)
LED's waiting on number's to order as follows.....
CREE XP-E Blue 3W LED with 55 degree White Lens
CREE XP-E Royal Blue 3W LED with 55 degree White Lens
CREE XP-G Neutral White 3W LED with 65 degree White Lens
CREE XP-G R5 Cool White 3W LED with 65 degree White Lens
CREE XM-L T6 3W LED on star (cool white)
Umm did I miss anything?
No easy answer to this as it depends on a number of factors - the heatsink, the LED's, the current used to drive the LED's and if any external cooling is employed.
As an example I have my LED's at 50mm centres mounted on aluminium angle, driven at 750ma with no external cooling. The heatsink gets warm, but not too hot to touch. The key it to ensure the LED's do not get too hot.
I plan on doing some research into heatsinks (but not tonight;)) but suffice to say that the greater the mass the better will be the heat transfer from the LED. I would assume that there would be some rating system but that will have to be left for another day.
Sounds like it is a fairly substantial heatsink - my experience, and anecdotal evidence, is that this type of heatsink is 'overkill' for a standard build. But, it does allow you to mount the LED's closer; or drive them at a higher current etc.
I think you would be better off deciding how many LED's you require and then sorting out how they are to be mounted.
On a 2.5' deep tank I would recommend around 80 degree lenses - any less and you will need to mount the LED's closer to avoid spot lighting.
Now to your drivers. With the Meanwell ELN-60-48D, the 60 refers to the watts and the 48 refers to the volts. The latter is the more important for our purposes. To determine the number of LED's which can be run off each driver we need to add up the Forward Voltage of each LED until we reach 48.
Whilst the forward voltage does vary slightly between each individual LED, and the current utilised the difference is minimal and we can refer to the product specs for an average:
XP-E Blue and Royal Blue - 3.4v @ 700ma
XP-G NW/CW - 3.2v @ 700ma
XM-L - 3v @ 1000ma
Keep in mind that the XM-L's can be driven up to 3A, although your drivers only go to about 1.5A.
So, on average, you can have around 13 XP-E or XP-G per driver, or 15 XM-L's - you need to allow a bit of overhead for the driver and the actual number will depend on the current utilised.
Not sure if you realise that the 'D' drivers are only dimmable via an analogue source and are not able to be automatically dimmed unless you have a Profilux??
Assuming this build is for your 10x2.5x2.5 I will have a think tomorrow about how many LED's you may require. You mention 4 runs the width of the tank - do you mean along the 10' length? And your heatsinks are about 5 ' long - how were you planning to arrange these?
Hope this provides some information for you to think about - if you could answer the couple of questions I will provide my further thoughts tomorrow.
Cheers
Synodontis Stay around for another half hour - I am just finishing off another post
Thank you kindly again good sir,
I didn't notice that the "D" is a pot dimmer, guess what's for sale in the near future!
I couldn't get that Google Sketch-up program to work the right way, so I have reverted back to the Kiwi version, build No - K42J65-NZ. The New Zealand edition works best for us. Below is how the heat sink's will be arranged over the tank.
They maybe overkill but will give room for any changes in the future as times/views change. We can add or subtract as required. The rendering process didn't pick up the finer detail so I have typed it below the image.
Tank edge bracing = 100mm wide
3x centre brace's = 160mm wide
Space between each heat sink = 100mm
Leading edge of first heat sink from front of tank = 115mm
Last edge of heat sink from rear of tank = 150mm
So there will be 6x 5Ft heat sinks.
Will go with the 80deg lenses on all the LED's. I have no idea how to work out how many LED's will be required :DIf we used the XM-L's, we would look into another type of driver, looked at the driver's from Inventronic's for larger power supply.
Was thinking I could get two strings on each heat sink?
For the number of LED's I think we will end up requiring, maybe just go for the bigger driver's? The 60-48D's are great for most tank's but the number needed may best be reduced with bigger driver's?
Lights will not be sitting on the tank edge, as depicted in the rather cool sketch-up image above. They will be suspended. We have planned on mounting the heat sink's to aluminum angle which will keep the spacing right and enable three units to be raised/lowered as we need.
This is so much fun!
"Build it and I'll buy it"
I didn't notice that the "D" is a pot dimmer, guess what's for sale in the near future!
I couldn't get that Google Sketch-up program to work the right way, so I have reverted back to the Kiwi version, build No - K42J65-NZ. The New Zealand edition works best for us. Below is how the heat sink's will be arranged over the tank.
They maybe overkill but will give room for any changes in the future as times/views change. We can add or subtract as required. The rendering process didn't pick up the finer detail so I have typed it below the image.
Tank edge bracing = 100mm wide
3x centre brace's = 160mm wide
Space between each heat sink = 100mm
Leading edge of first heat sink from front of tank = 115mm
Last edge of heat sink from rear of tank = 150mm
So there will be 6x 5Ft heat sinks.
Will go with the 80deg lenses on all the LED's. I have no idea how to work out how many LED's will be required :DIf we used the XM-L's, we would look into another type of driver, looked at the driver's from Inventronic's for larger power supply.
Was thinking I could get two strings on each heat sink?
For the number of LED's I think we will end up requiring, maybe just go for the bigger driver's? The 60-48D's are great for most tank's but the number needed may best be reduced with bigger driver's?
Lights will not be sitting on the tank edge, as depicted in the rather cool sketch-up image above. They will be suspended. We have planned on mounting the heat sink's to aluminum angle which will keep the spacing right and enable three units to be raised/lowered as we need.
This is so much fun!
"Build it and I'll buy it"
Hi Ken and Jen
I have read your post again and I am still not sure how you are planning to arrange your heatsinks. We will worry about that later.
Lets have a go at working out how many LED's you might need. I am going to approach this 2 ways and we will see where we end up...
If we use the guide available here http://www.thereefuge.com/threads/diy-led-build-all-you-need-to-know.737/#post-9101 we would need between 190 and 280 3w LED's to achieve a medium to high light level, driven at around 750mA. I have 60 on a 4x2x2 - about 6 more would be good - which extrapolates out to 206. This is in the same ballpark i.e. around 200 to 220 LED's is probably about right for your tank. You could get away with less by having them concentrated over bommies etc but probably not much less than 180. Assuming you had 220 LED's with 40% XP-G's and 60% XP-E's this would equate to around 39,204 lumens of light.
Now, lets compare this to the new Illumagic LED Lights - it would appear that you would need 5 x 2' units to cover your tank. Each 2' unit comprises 8 White XP-G's, 16 Blue XP-E's, 4 Purple and 4 UV. Over 5 units we would have 40 XP-G's, 80 XP-E's plus 20 Purple and 20 UV. The white and blue LED's are driven at 1000mA whereas the purple and UV are only driven at 350mA. This equates to around 20,000 lumens not including the purple or UV LED's. These lights have a built in 70 degree optic and are no doubt designed to operate very efficiently.
Lets assume that these are 30% more efficient than your DIY build - you would need to provide around 26,000 lumens. This equates to around 58 XP-G's and 87 XP-E's to provide an equivalent amount of light - this is quite a bit different from our first calculation :confused:.
What does all this mean?? With any DIY build we tend to over estimate what is required (just have a look at my stand, I reckon it would support an elephant!!) whereas a commercial product will try to minimise the inputs in order to increase their profit margin (this is more of a general comment rather being aimed at a particular product). Many of the new LED fixtures available certainly have a smaller number of LED's than that typically found in DIY builds.
In summary (and sort of combining the two calculations), I would say you need around 65 XP-G's (5 strings of 13 LED's - 5 drivers) + 91 XP-E's (7 strings of 13 LED's - 7 drivers).
Now for the XM-L question - it appears that not many people are using these over reefs at the moment because there is only a limited number of bins (colour ranges) available. The XP-G produces 348 lumens at 1,000mA whereas the XM-L produces around 388 lumens at the same current - so around 11% more efficient. You could reduce the number of white LED's by having XM-L's but I am not sure that you will be able to find the right bins.
Were you looking to dim these LED's??
Hope this make some sense!!
Any and all questions welcome:D
I have read your post again and I am still not sure how you are planning to arrange your heatsinks. We will worry about that later.
Lets have a go at working out how many LED's you might need. I am going to approach this 2 ways and we will see where we end up...
If we use the guide available here http://www.thereefuge.com/threads/diy-led-build-all-you-need-to-know.737/#post-9101 we would need between 190 and 280 3w LED's to achieve a medium to high light level, driven at around 750mA. I have 60 on a 4x2x2 - about 6 more would be good - which extrapolates out to 206. This is in the same ballpark i.e. around 200 to 220 LED's is probably about right for your tank. You could get away with less by having them concentrated over bommies etc but probably not much less than 180. Assuming you had 220 LED's with 40% XP-G's and 60% XP-E's this would equate to around 39,204 lumens of light.
Now, lets compare this to the new Illumagic LED Lights - it would appear that you would need 5 x 2' units to cover your tank. Each 2' unit comprises 8 White XP-G's, 16 Blue XP-E's, 4 Purple and 4 UV. Over 5 units we would have 40 XP-G's, 80 XP-E's plus 20 Purple and 20 UV. The white and blue LED's are driven at 1000mA whereas the purple and UV are only driven at 350mA. This equates to around 20,000 lumens not including the purple or UV LED's. These lights have a built in 70 degree optic and are no doubt designed to operate very efficiently.
Lets assume that these are 30% more efficient than your DIY build - you would need to provide around 26,000 lumens. This equates to around 58 XP-G's and 87 XP-E's to provide an equivalent amount of light - this is quite a bit different from our first calculation :confused:.
What does all this mean?? With any DIY build we tend to over estimate what is required (just have a look at my stand, I reckon it would support an elephant!!) whereas a commercial product will try to minimise the inputs in order to increase their profit margin (this is more of a general comment rather being aimed at a particular product). Many of the new LED fixtures available certainly have a smaller number of LED's than that typically found in DIY builds.
In summary (and sort of combining the two calculations), I would say you need around 65 XP-G's (5 strings of 13 LED's - 5 drivers) + 91 XP-E's (7 strings of 13 LED's - 7 drivers).
Now for the XM-L question - it appears that not many people are using these over reefs at the moment because there is only a limited number of bins (colour ranges) available. The XP-G produces 348 lumens at 1,000mA whereas the XM-L produces around 388 lumens at the same current - so around 11% more efficient. You could reduce the number of white LED's by having XM-L's but I am not sure that you will be able to find the right bins.
Were you looking to dim these LED's??
Hope this make some sense!!
Any and all questions welcome:D
Thanks Magic that is brilliant :D
As for the number needed, probably a little less then what I was expecting. As you say tho, we all tend to "over estimate"
As for the 6x heat sink's, we could always place two together which would result in four heat sink's 5Ft long by 196mm wide.
Basically the end result will be two 5Ft unit's side by side.
You have given me lot's to think about, will have to do some math's and think about how to run a wire or two.
As for the number needed, probably a little less then what I was expecting. As you say tho, we all tend to "over estimate"
As for the 6x heat sink's, we could always place two together which would result in four heat sink's 5Ft long by 196mm wide.
Basically the end result will be two 5Ft unit's side by side.
You have given me lot's to think about, will have to do some math's and think about how to run a wire or two.
4 could work - 13 XP-G's + 26 XP-E's on each?? I am close to ordering some purples to try on mine as this seems to be the way that some of the commercial products are going. The 60-48 driver will actually go to 52.8v so you could fit in an extra XP-G or two.
What about dimming - it would be a shame not to have sunrise/sunset ramp on a big build like this??
What about dimming - it would be a shame not to have sunrise/sunset ramp on a big build like this??
Yeah we do want to have dimming, that's why we will offer for sale the D units we have and replace with the P. I'm a very lazy man and I want a remote control dimmer thingy:D
Just checked and the LED's come in just under the magic $1000 mark. Will get a few purple's also, I like the sound of them. Started playing with the real sketchup so will post something in a few days.
Just checked and the LED's come in just under the magic $1000 mark. Will get a few purple's also, I like the sound of them. Started playing with the real sketchup so will post something in a few days.
I just put the numbers into rapid, never thought about it being in US dollars :(
Will price it all up on the rapid check out and see if cutter's can match it?
Have decided to go with four heat sink's, each one will be 1.5m long by 200mm wide.
"I'm a very lazy man and I want a remote control dimmer thingy" is the tech term for a remote control dimmer so I can leave my ass on the couch and push buttons and/or just leave it to do it's own thing. I like the idea of putting in a "LED code" and the controller works it out from there.
Will price it all up on the rapid check out and see if cutter's can match it?
Have decided to go with four heat sink's, each one will be 1.5m long by 200mm wide.
"I'm a very lazy man and I want a remote control dimmer thingy" is the tech term for a remote control dimmer so I can leave my ass on the couch and push buttons and/or just leave it to do it's own thing. I like the idea of putting in a "LED code" and the controller works it out from there.
Haha, that's cool.
Was just going to price up what I could as in LED's on stars with lenses, then stop in at cutter's and LED sales to see if they could match or come close. I figure it will be around a 1G just in LED's and the way most business's are at the moment that's a half decent sale on a $10 product
Was just going to price up what I could as in LED's on stars with lenses, then stop in at cutter's and LED sales to see if they could match or come close. I figure it will be around a 1G just in LED's and the way most business's are at the moment that's a half decent sale on a $10 product
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