First LED Build

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Plastidip

Member
I live in an area where it is in the 80's (F) for most of the summer with a few 100+ days. Currently I have 200w T5 grow area (about 2x4 feet) and a 400w HPS in about 2.5x4 feet. I don't grow commercially and I pay for my electricity.

I have a background in I.T., construction and DIY/Maker type culture.

After much thought and reading it appears LEDs can really help solve my heat problems and my ridiculous electric bill.

I will add pictures later today, but here's what I'm working on:

This is built around 4 x 3500K Cree CXB3590 COBS
I have 3"x3"x3/8" aluminum plates drilled and tapped for the ideal holder and the reflector adapter on one side.
The other side is drilled and tapped for a copper based CPU water block. My first is setup with an old swiftec block I had on a shelf. I have an inexpensive Chinese CPU water block on order as a likely candidate for the other three.
I have a 14,000 BTU commercial A/C unit I was getting rid of but I am now going to use its fan and coils as my radiator. This radiator is huge. I am going to place it in my basement (right below my grow space) where it is between 40F and 70F degrees all year long.

The biggest issue with this is protecting the COBs from overheating. I have a Raspberry Pi and an 8 channel relay board. This will allow, complex light timings (COBs, their dimming, far red stars, uv...), sensing heat at the block and controlling the water pump and fan.

-Liam
 
canadian1969

canadian1969

Well-Known Member
Love the ideas, I would worry about the cooling , fluid cooling is great in a server, but if anything happens during your grow, you could kill your lights as well as the plants. (you cant backup your plants) I would hate to see your cooling solution fail due to some glitch or equipment issue. Passive or active cooling will be way safer. imho
 
Airwalker16

Airwalker16

Well-Known Member
Plastidip said:
I live in an area where it is in the 80's (F) for most of the summer with a few 100+ days. Currently I have 200w T5 grow area (about 2x4 feet) and a 400w HPS in about 2.5x4 feet. I don't grow commercially and I pay for my electricity.

I have a background in I.T., construction and DIY/Maker type culture.

After much thought and reading it appears LEDs can really help solve my heat problems and my ridiculous electric bill.

I will add pictures later today, but here's what I'm working on:

This is built around 4 x 3500K Cree CXB3590 COBS
I have 3"x3"x3/8" aluminum plates drilled and tapped for the ideal holder and the reflector adapter on one side.
The other side is drilled and tapped for a copper based CPU water block. My first is setup with an old swiftec block I had on a shelf. I have an inexpensive Chinese CPU water block on order as a likely candidate for the other three.
I have a 14,000 BTU commercial A/C unit I was getting rid of but I am now going to use its fan and coils as my radiator. This radiator is huge. I am going to place it in my basement (right below my grow space) where it is between 40F and 70F degrees all year long.

The biggest issue with this is protecting the COBs from overheating. I have a Raspberry Pi and an 8 channel relay board. This will allow, complex light timings (COBs, their dimming, far red stars, uv...), sensing heat at the block and controlling the water pump and fan.

-Liam
Click to expand...
Ya man, not smart. Way inventive and ingenious but not optimal for grow lights.
 
V

VegasWinner

Well-Known Member
Plastidip said:
I live in an area where it is in the 80's (F) for most of the summer with a few 100+ days. Currently I have 200w T5 grow area (about 2x4 feet) and a 400w HPS in about 2.5x4 feet. I don't grow commercially and I pay for my electricity.

I have a background in I.T., construction and DIY/Maker type culture.

After much thought and reading it appears LEDs can really help solve my heat problems and my ridiculous electric bill.

I will add pictures later today, but here's what I'm working on:

This is built around 4 x 3500K Cree CXB3590 COBS
I have 3"x3"x3/8" aluminum plates drilled and tapped for the ideal holder and the reflector adapter on one side.
The other side is drilled and tapped for a copper based CPU water block. My first is setup with an old swiftec block I had on a shelf. I have an inexpensive Chinese CPU water block on order as a likely candidate for the other three.
I have a 14,000 BTU commercial A/C unit I was getting rid of but I am now going to use its fan and coils as my radiator. This radiator is huge. I am going to place it in my basement (right below my grow space) where it is between 40F and 70F degrees all year long.

The biggest issue with this is protecting the COBs from overheating. I have a Raspberry Pi and an 8 channel relay board. This will allow, complex light timings (COBs, their dimming, far red stars, uv...), sensing heat at the block and controlling the water pump and fan.

-Liam
Click to expand...
Why not use traditional heat sinks either active or passive? not a lot of heat at 50W/COB to remove. More heat from u/lumens than anything else. Exhaust will remove 75% of your cob heat from heat sinks easily. plenty of folks with some good heat sinks available cost effectively from $20/each to 5.88"x18" finned heat sinks. peace
 
dandyrandy

dandyrandy

Well-Known Member
I use ~700w of cob leds in 11 sq ft. Closed and stealth. Built into a wall. Bottom vent and the build is a passive coolhood design. I hang wireless thermometers 6 to 8" below the lights. I never see above 83 or so. The canopy below another 6" is cooler. No air. ~ 70 cfm cools it all.
 
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Plastidip

Member
How do you cool the lights with 80-100F air? I can't really duct air from the basement. 1000cfm of 90F air can't really help me. Active heat sinks have all of the drawbacks of liquid cooling, only less efficiently. I can cool the space with two heat exchangers, fans and heat sinks but air is poorly thermally conductive. No matter what I do the space will be in danger of over heating. If I grow from June to October I have to monitor the temperature and kill the lights if the space overheats. Cycling the lights at night helps but doesn't solve the problem.

5-12-16 069.JPG
5-12-16 070.JPG
Here are pics before I flattened and polished.
 
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Airwalker16

Airwalker16

Well-Known Member
Plastidip said:
How do you cool the lights with 80-100F air? I can't really duct air from the basement. 1000cfm of 90F air can't really help me. Active heat sinks have all of the drawbacks of liquid cooling, only less efficiently. I can cool the space with two heat exchangers, fans and heat sinks but air is poorly thermally conductive. No matter what I do the space will be in danger of over heating. If I grow from June to October I have to monitor the temperature and kill the lights if the space overheats. Cycling the lights at night helps but doesn't solve the problem.

View attachment 3679959
View attachment 3679960
Here are pics before I flattened and polished.
Click to expand...
You should have just thermal glued the cob directly to the water block :P
Well a 3070 at least would fit.
Probably not your 3590's though.
 
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Plastidip

Member
I hadn't thought of epoxy...
It appears that standard CPU heat block size is 50mmx50mm, so the cob would fit, but not the holder.
 
Rahz

Rahz

Well-Known Member
I don't see why it won't work, but it's not correct to think it's not possible to air cool a cob in a 90 degree environment. With a good sink/fan combo you can get less than 10C rise over ambient, so at 90F it's possible to keep the cobs under 40C which is very respectable... although hopefully the air at the canopy is going to be a few degrees less than 90. 30C is optimal.
 
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Plastidip

Member
Rahz said:
I don't see why it won't work, but it's not correct to think it's not possible to air cool a cob in a 90 degree environment. With a good sink/fan combo you can get less than 10C rise over ambient, so at 90F it's possible to keep the cobs under 40C which is very respectable... although hopefully the air at the canopy is going to be a few degrees less than 90. 30C is optimal.
Click to expand...
Very true, and that's what I do now with a 400W HPS during the cooler months.

As things stand I use my house to store cool air collected at night and push hot air through my attic to the outside. My basement stays cool all year round and this seems like the most efficient way to exploit the resource.

My COBs arrive Monday. I need to add a temperature sensor to the aluminum block over the weekend.
 
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