Custom HPS/CFL Hood
Where to begin... Like alot of you, I build pretty much EVERYTHING myself. My own grow cabs, boxes, lights, hoods, cooling systems, etc. etc. But my most recent light/hood is my far my favorite. I figured I'd throw my idea out there and see if some of you might be interested in building your own. I considered selling lights/hoods/hydro/areo setups on craigslist but I kind of figured I might draw a little more attention to myself than I would like. So I'll do the next best thing and share what I know with you all. But I must first say, I don't know if it's been done before and I'm far from an expert, just a guy with alot of carpentry experience. So, that being said...
I started off with an aquarium light first and gutted it out. Where the light bulb went, I put a blank piece of metal over it for a clean slate to work with. After I decided how many and of what kind of lights I wanted I mocked up where they would go. 2 sockets for HPS and 3 for CFL's. Because it was designed to light a very small area, and because I got them for 15 bucks a piece, I used 70watt HPS's. (gotta love home depot) In the 3 standard sockets I used the Y adapter, which allows me to run 6 CFL's instead of 3. I just ran the cords out of the top where the vents were and BAM. Now on to the hood itself. I read through Jorge Cervantes's book and found that the "batwing" style hood worked pretty darn good. But like most things, it kept evolving. Soon after I enclosed the ends but then heat became an issue so on one end I cut a 4 inch hole and ran a small duct up to the fan which draws so well, the temps started to get to low, lol. Gotta love it. Simple fix, less fan. So there you go. Very rough description but I believe the essentials are there. It's kinda late for me right now but I'll come back and give a more vivid description and real photos. You'll have to settle for crude "paint" pics. Feel free to ask me any questions. Obviously you can use any combo of lights. Or any number of them. My next goal is to build an insane light with MANY CFL's and higher wattage of HPS and of course a piece of glass to fully enclose the hood. Now, you don't have to use an aquarium light like I did. Any box type enclosure would work. My next one will be a simple hand made "box" with multiple lights. And a little side info, the metal I used to build it with is coil stock used usually for bending metal for vinal siding. This particular stock was flat white which worked out pretty well for me. Also metal "flashing" works but you have to get the wide stuff. The metal stock I use is around 3 feet wide, maybe a little more. But please, if you don't have decent building/carpenter/electrical experience, please don't try this. I don't want to hear about someones "house" burning or someone cutting off a didget.
Last edited by Lessernot; May-25-2011 at 00:00.
Also, a good starting point would be one of those multi-light bathroom fixtures. The base model works fine. Usually has between 3-10 light sockets I believe and they are fairly cheap at most home improvement stores. Alot of the times they have some on sale. Just take it about to wire in your HPS/MHL and add your metal for the hood and presto chango. Another little idea is if your just using a single light, you can get a shop/drop light to use as a starting point to build a larger relector, the round/octogon style.
CFL need to be within 6 inches of the bulb, 2 inches is recommended. HPS bulbs cannot get that close with out burning foilage. HPS bulbs need at least 18 inches depending on how well you cool the bulb. Most hps bulbs are 1-3 feet away from canopy, at this distance the CFLS are just about useless. Also HPS bulbs should be positioned horizontally to distribute light efficiently, there are vertical bulbs though. Bulbs are designed to operate in a certain orientation, its bad to use a bulb in the wrong orientation.
I use a 800 cfm fan and 3 layers of insulation to keep my 1000 X 2 cool and to keep the hood from radiating heat upwards. They make a lot of heat.
There is a science to making reflectors, if you have a bad reflector you are wasting lots of light. Which means lower yields.
So ditch the cfls and just use hps's. You could use the cfls if you just lower the socket cords down to the canopy. If your plants grow fast you have to raise the cfls every other day.
Its funny the temps got so low after they were to hot. Its always one thing or the other. I remomend a thermostate, but because you like to DIY I bet you could build one.
Your the first person Ive seen build there own hood, congrats.
Last edited by CrackLemonade; Jul-07-2011 at 19:04.