Just thought I would copy this over from another forum!
New on here and to growing really...started growing around 4/5 months ago with a small outdoor guerrilla grow after years of considering a spot....as expected slugs annihilated the whole crop! but then a friend allowed me to have a small indoor setup in his spare room...been growing under MH/HPS fixtures in a 0.8 x 0.8m tent but to cover it properly ive found the 250W just isnt enough to cover 4 small autos in there, but the heat from the 400W is just unreal.
So after some consideration I toy'd with the idea of investmenting in one larger or a few smaller LED fixtures to try and give the same quantity of light as the 400W HPS/MH but with a fraction of the heat. I was as usual nearly sold on buying a MARS Hydro light but after some research I wasnt entirely sold. Some people rant and rave about them being great yet others have said they are turd....then I came accross expensive brands which for me being a beginner decided against investing £600+ on an LED light....
Then I came accross someone commenting on how much better someone with MARS lights would do if they just invested in some COB's. This got me thinking and I decided to dive into it all and learned some serious amount about them and was sold within a couple of days. All I will say is the info that people on this forum and elsewhere have provided is just insane and I am thankful. I belong to a few car forums and my god the useless information people try to give to you is insane. My main thanks go to Growmau5 and Supra for the info and the calculators etc. You could rely on their information alone and be incredibly knowledgeable within a few hours.
Anyway onto the more interesting stuff i suppose! I wanted to build the whole light for under £250, but i think the total I have spent is in the region of around £300.
I initially went for Citizen COBs due to the price but after running the calculator the efficiencies were around 42% which weren't high enough for me to justify the cost. I looked into CREE COB's and they run much much more efficiently or I had just set something wrong with the Citizens in the calculator.
The setup im going for is...
4 No. CXA3070 4000k (£70 off ebay delivered)
4 No. CXB3590 3500k (£170 kingbrite included meanwell driver)
1 No. Meanwell H185-C700B
8 No. Artic Alpine 64 GT (£55 including heatsink)
Aluminium Angle incl. all cuts (£25 delivered)
This totalled around £320 delivered to my door, I already have wire, solder, heatshrink and bolts etc at mine from previous projects and car building so I didnt really factor them in...
This setup gave me 37,823 lumens over my 0.64m² / 7ft² which was around the same as what a 400W HPS would give, but at an efficiency circa 63%. This means our of the 200W drawn from the wall im only seeing around 76W of heat into the tent where as at a guess a 400W HPS would be giving me 260W. So I should see a dramatic reduction in heat into the tent and also maintain very similar light levels to the 400W light.
I believe it gave me a PPFD of around 752.33 (unless I calculated wrong).
I have also bought a few things that I hope safe guards my light but also is just a fancy few tricks. I bought a potentiometer to dim the light for seedlings and small plants. But I have also bought some temperature switches I intend on drilling and mounting inside the one of the LED heatsinks/CPU coolers. I bought a normally closed temp switch for 75°C, which I may up to 85°C if anyone has any advice. So this will be mounted in the heatsink of one COB, probably the 3070 as I expect them to run hotter due to being the smaller COB. If this rises to above 75°C the switch opens and breaks the circuit cutting power to the driver. This is more of a failsafe if the fans have stopped working on the CPU coolers and incase a fire starts. The set point of 75°C may be too low so any advice would be appreciated. I dont intend on the COB's ever getting this hot being actively cooled.
The other temp switch is a normally open switch, and when the temperature of the LED is below say 40°C the switch will stay open, when it goes above 45°C the switch will close, allowing power to run through the fans on the CPU coolers. So most of the time im hoping the CPU coolers will run passively and the fans will only run when required to, very small power saving but also for noise. Has anyone integrated some form of controls like this before and is it actually worth it? The switches only cost a couple of pounds each.
Anyway onto some photos of the bits that have arrived and a basic layout I drew on autocad. Any suggestions or advice is always welcome! I expect to run the CXB3590 COB's in 4 corners and put the CXA3070 4000K on the middle 4. Would that layout be a good one to go for? Im not sure how the 4000K will differ from the 3500K but I will be using the light to veg and flower.
Since the original purchasing I have bought some AM3 motherboard brackets to run attach the Heatsinks to the frame which will allow for quick removal of them...they were £1 each, and I have bought some of the cheaper 2 peice COB holders for I believe around £1 each as well...so I have upped the cost of the build slightly but I believe the little things will give it a nice touch and not as much of a bodge job...
I will update as the build continues!
New on here and to growing really...started growing around 4/5 months ago with a small outdoor guerrilla grow after years of considering a spot....as expected slugs annihilated the whole crop! but then a friend allowed me to have a small indoor setup in his spare room...been growing under MH/HPS fixtures in a 0.8 x 0.8m tent but to cover it properly ive found the 250W just isnt enough to cover 4 small autos in there, but the heat from the 400W is just unreal.
So after some consideration I toy'd with the idea of investmenting in one larger or a few smaller LED fixtures to try and give the same quantity of light as the 400W HPS/MH but with a fraction of the heat. I was as usual nearly sold on buying a MARS Hydro light but after some research I wasnt entirely sold. Some people rant and rave about them being great yet others have said they are turd....then I came accross expensive brands which for me being a beginner decided against investing £600+ on an LED light....
Then I came accross someone commenting on how much better someone with MARS lights would do if they just invested in some COB's. This got me thinking and I decided to dive into it all and learned some serious amount about them and was sold within a couple of days. All I will say is the info that people on this forum and elsewhere have provided is just insane and I am thankful. I belong to a few car forums and my god the useless information people try to give to you is insane. My main thanks go to Growmau5 and Supra for the info and the calculators etc. You could rely on their information alone and be incredibly knowledgeable within a few hours.
Anyway onto the more interesting stuff i suppose! I wanted to build the whole light for under £250, but i think the total I have spent is in the region of around £300.
I initially went for Citizen COBs due to the price but after running the calculator the efficiencies were around 42% which weren't high enough for me to justify the cost. I looked into CREE COB's and they run much much more efficiently or I had just set something wrong with the Citizens in the calculator.
The setup im going for is...
4 No. CXA3070 4000k (£70 off ebay delivered)
4 No. CXB3590 3500k (£170 kingbrite included meanwell driver)
1 No. Meanwell H185-C700B
8 No. Artic Alpine 64 GT (£55 including heatsink)
Aluminium Angle incl. all cuts (£25 delivered)
This totalled around £320 delivered to my door, I already have wire, solder, heatshrink and bolts etc at mine from previous projects and car building so I didnt really factor them in...
This setup gave me 37,823 lumens over my 0.64m² / 7ft² which was around the same as what a 400W HPS would give, but at an efficiency circa 63%. This means our of the 200W drawn from the wall im only seeing around 76W of heat into the tent where as at a guess a 400W HPS would be giving me 260W. So I should see a dramatic reduction in heat into the tent and also maintain very similar light levels to the 400W light.
I believe it gave me a PPFD of around 752.33 (unless I calculated wrong).
I have also bought a few things that I hope safe guards my light but also is just a fancy few tricks. I bought a potentiometer to dim the light for seedlings and small plants. But I have also bought some temperature switches I intend on drilling and mounting inside the one of the LED heatsinks/CPU coolers. I bought a normally closed temp switch for 75°C, which I may up to 85°C if anyone has any advice. So this will be mounted in the heatsink of one COB, probably the 3070 as I expect them to run hotter due to being the smaller COB. If this rises to above 75°C the switch opens and breaks the circuit cutting power to the driver. This is more of a failsafe if the fans have stopped working on the CPU coolers and incase a fire starts. The set point of 75°C may be too low so any advice would be appreciated. I dont intend on the COB's ever getting this hot being actively cooled.
The other temp switch is a normally open switch, and when the temperature of the LED is below say 40°C the switch will stay open, when it goes above 45°C the switch will close, allowing power to run through the fans on the CPU coolers. So most of the time im hoping the CPU coolers will run passively and the fans will only run when required to, very small power saving but also for noise. Has anyone integrated some form of controls like this before and is it actually worth it? The switches only cost a couple of pounds each.
Anyway onto some photos of the bits that have arrived and a basic layout I drew on autocad. Any suggestions or advice is always welcome! I expect to run the CXB3590 COB's in 4 corners and put the CXA3070 4000K on the middle 4. Would that layout be a good one to go for? Im not sure how the 4000K will differ from the 3500K but I will be using the light to veg and flower.
Since the original purchasing I have bought some AM3 motherboard brackets to run attach the Heatsinks to the frame which will allow for quick removal of them...they were £1 each, and I have bought some of the cheaper 2 peice COB holders for I believe around £1 each as well...so I have upped the cost of the build slightly but I believe the little things will give it a nice touch and not as much of a bodge job...
I will update as the build continues!
