New cab design, input appreciated.

[lostinethereal]

So I have this nice box I would like to turn into a cool tubed 150w HPS box, maybe a few cfls but I don't think so. I just want to keep it nice and simple, but would like some input from some other people. I like the design, and I have a mockup of how I'd like it to turn out after it's finished. I was tired of messing with Sketchup so you'll have to use your mind's eye to envision the rest.

I was looking around and I think this is probably my best option for a fan and filter is this it would cost just about $160 shipped and I think it'll get the job done just nicely. But that's why I'd like the input, I realize I could probably get by with less, maybe cheaper, or maybe more expensive for better stuff, but I'm absolutely broke but don't want to cheap out too much. Anyway, so besides that I'll be DIY remote ballasting and cooltubing a 150w hps and was thinking the fan should be strong enough to cool another 150 or a higher wattage (say 250w hps, or 150w hps+75w mh, etc) some time?

The cabs outside dimensions are 30" wide, 29" tall and 18" deep or so. The usable interior space is slightly less obviously, but the "bottom" of the inside is 4" from the real bottom, so it's really about 24" inside. There's already a shelf inside which I'm going to put on tracks for easy access to the plants. I may mount the filter parallel to the cool tube, with the fan in the same position (that's really the only place for it). Beneath/beside the fan is where the electronics will be mounted. Underneath the shelf I'm going to have 2x 8x8 dark room louvers, I think I might need to drill some holes in the shelf to aid in airflow. In the sketchup mockup, the exhaust is straight out of the tube to the back, it'll be different in the real cab so there wont be any light shining out of the back. Maybe another dark room louver some how, I got an idea or two.




Probably be going with soil, I'll figure that out once I finalize the cab design and actually start working on it. Anyway, thanks for taking a gander at my cab design and thanks in advance for any comments/questions/input. I need to do some saving for this cab but if you guys think the filter/fan will work than that's the first thing I can save for and cross off, probably the most expensive component(s) for the whole cab.

 

[kaljukajakas]

I'd say that fan is more than enough for such a small cabinet and as it seems you have at most about 18" by 20" of usable space a 150W HPS is well suited for the job. A 250W HPS might be overkill but the fan should be able to handle it no problem, unless you live in a very hot place. I'd go with a smaller fan to get more space for growing. Perhaps something like these: http://www.solerpalau-usa.com/brochures/technical/TD Mixvent Series.pdf

The mixed flow fans have a smaller diameter while still giving respectable flow rates and pressures.

You could also try to place the electronics, fan and filter in the 3.5" high or so space under the cabinet and ditch the shelf. That'd take some serious DIY though. You'd could make a flat carbon filter and there are some very flat centrifugal fans out there etc. Or if you get a small diameter inline fan you could just stick it on the cool tube as there's should be enough space for that and just put the filter, ballast and light traps under the cabinet.

 

[FreezerBoy]

fan-intake calculator
Great Inline fans

Above are a link to determine your exact needs and one discussing the S&P mixed vent fans. I don't have one but, I can say the Inlines you're looking at are LOUD and big. Note there's no such thing as a silent fan. You'll want something to pin the noise on or, mask it. An aquarium or desk fan ...

 

[lostinethereal]

Thanks for the links you two, I remember that thread for the fans Freezerboy. I considered doing one of the bathroom exhaust fans with the DIY square carbon housing sitting on top, ala someones DIY tutorial (don't remember whom). However, I'm what I'd consider fairly capable when it comes to carpentry and whatever but I don't have the time/space to too many modifications. I'd like to keep it cheap and sort of simple, fan/filter combo helps the cause, leaving only the tube and remote ballasting to myself.

And thanks for the idea kaljukajakas, I could try to place the electronics underneath but I think the remote ballast could be a fire concern. If I keep it behind/beside the fan I could have all that stuff neatly mounted and visible but out of the way.

I have these rubber/foam mats at work we stand on in front of the machine, they're designed to be easily cut. I could take a square of it and use it to help absorb some of the vibrations from the fan. Which I'll be using this cab to set my TV on or an aquarium, something to blame the noise on.

 

[kaljukajakas]

Right, you'd have to have some air moving over the ballast for sure if it were in the bottom.

Perhaps there is a simple and fast way to make a flat carbon filter: get some 1x1 and make a ~18" by ~30" flat rectangular frame that fits inside the walls of the bottom 4" section of your cabinet. Now take some wire mesh and a stapler and some filter cloth/polyfill and staple them to one side of the frame, wire mesh on top of the polyfill. Then flip and fill the frame with a layer of carbon and again staple polyfill and wire mesh onto the frame. Put the frame inside the bottom of the cabinet, say 1" from the floor. Tape it in there tight, add a few screws and also tape shut the back side of you cabinet (I assume it doesn't have a cover there). Now if you blow air into the bottom section of of your cabinet the air fill have to travel through the filter.

Distributing the air pressure that meets the carbon evenly is a bit of an issue though and it'd be better to exhaust through the top... You could seal off the very bottom of the cabinet with some thin chipboard and make a 4" hole in the carbon filter (make the rectangular frame so one of it's corners is stepped) so the entire bottom of the cabinet becomes a filter and the air would come in from the growspace, go through the filter and exit back up the 4" tube going up to the fan. To equalize the pressure you could simply drill a bunch of small holes in the "ceiling" of the filter compartment.

Foam rubber should be good for sound insulation. Get a fan speed controller also if you can and dial it in to your desired temperatures. It's far easier to generate less noise than to get rid of an excess.