# DIY LED Air Cooled Hood



## Dogweed (Mar 4, 2018)

Thought I might throw a little help to those who struggle with heat or just want a more efficient way to remove more heat from their LEDs.  I was using a 600w HPS and I was always fighting to keep my tent under 85. So I decided to try my hand at LEDs, hearing that they put off less heat. I didnt want to sacrifice power so I went with a LED that pulls 645w from the wall. And to my disappointment it also puts out a lot of heat still. Honestly the tent was better off with the cool hood for the HPS. I noticed the heat was coming from the heat sinks and the fans from the light was circulating the hot air around the tent. So instead of having a hot layer up high with lower temps low in the tent. The whole tent was evenly hot. 
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First thing I tried was to put the LED in my HPS hood but the light was quite a bit larger than the hood. So I put on my thinking cap and started to plan out a box. 
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Looking at my light most of the air flow comes in through the top and out the sides. There are vents for air on the ends but not much air actually flows out of the ends.  With that in mind I dont need much extra space for length but should keep a few extra inches on the sides to allow the hot air to escape the light. 
My box ended up being 26"L x 22"w x 9"H . 26" gives me 1 inch on either end where my in and out ports will be. The 22" gives me 3 inches on either side of the light allowing the hot air to flow out of the light without too much restriction. The 9 inches is to allow for the 2 inches of the frame and 1 inch of the 6" duct flange. 
Now that I have the dimensions I need. I can start to make the frame. I decided to use a 1" thick board and rip it to 1x1 and chop them up on the chop saw. 
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Once the frame was cut up I put it together using a nail gun. If you dont have a nail gun I recommend pre drilling the holes to keep it from splitting.
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I used and definitely recommend 1/4" plywood or something similar. It helps keep the weight down, which adds up quick. 
For the bottom piece I cut 4 1x1" corner pieces out so that it could sit on top of the bottom part of the frame. That way the weight of the light would be on the frame itself and not the nails or screws used to hold the piece on.  
Also if you look closely you will see I traced the light and cut 3/4" inside of it. That gives the light a 3/4" rim to rest on.  Every other piece was cut to length. And 2 6" holes were cut out of the ends. 
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Once the bottom was put in place and secured, I added an after thought. I cut 8 45* pieces to put them in the corners of the frame and drilled 1/2" holes through them. This was going to be my hanging points with 12" Eye Hooks. They would also hold ALL of the weight. 
I put double sided tape around the light opening so that the light would not slide around inside of the box if bumped or moved.  
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I also wanted a way to focus some of the air through the light. I wasnt sure when the tent exhaust kicked in if the air flow would be to fast and bypass the light causing hot pockets. So I created an air trap using peg board.  It doesn't stop the air entirely, it can flow through the holes or go around it on the sides. But the main flow of air comes straight in and builds up above and then flows through the light.  This was mounted on the top lid. 
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Almost done, just got to put the fail safe wires in so if any part of the box fails, the light wont crash down into my plants. Hopefully saving both the light and the plants. These I ran up through the holes for the eye hooks then used hanger clips to hook it to a DIFFERENT part of the tent frame than the box itself is mounted on. That way if the cross bars the box is attached to bend or fails under the weight there's at least one other mount holding it up. The over all weight is prolly close to 30 lbs, the light it self is 22 lbs. 
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And here she is all wrapped up in white tape and hung where she will be for hopefully a long long time. 
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## screwdriver (Mar 9, 2018)

Is there an external fan used?  Size, cfm?


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## Dogweed (Mar 10, 2018)

Yes there is, I have 2 fans that run my exhaust. The first fan is a 6" 440 cfm inline fan added right after the carbon filter and just before the light box. You can see its power cord in the last photo from the first post. This fan comes on when the tent gets to 80.
 The second one is a bathroom ceiling fan that I connected the exhaust pipes to. This one runs 24/7 at about 40-60 cfm. This fan wasn't doing a whole lot of cooling until I got the LED and put it in the box. Now its just about the only fan that runs.
The intake for the tent is just a 4" flexible duct I lay either on the floor or put in a window. But since I switched to the boxed LED, I haven't needed to take the cool winter air from outside yet. 

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## Locked (Mar 10, 2018)

Wow, awesome work.


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