New grow box build. With pics.

Azazel35

Member
So I built a new stealth grow box. It's 2'x2'x4'.



So for the intake and exhaust I used blowers from a couple of microwaves.
Bottom,

Top,


As for carbon filter, I made a couple boxes filled with carbon.


Here's inside, front and back.




On the door I was going use the lock on it. But then I decided drill couple holes and I used ally wrench to slide in as a lock pin.
 

Azazel35

Member
I do have a question about the air inside it. When I close the door, fans get a little louder. When I open door I feel air push out. Top fan is on high bottom on low. Does that mean it's not exhausting air fast enough? Is it something I need to try and correct?
 

coreywebster

Well-Known Member
If the fans are getting loud when you close the door its likely that sealing it off is causing your fans to work extra hard to bring air in and out. Sounds like you are creating positive pressure too. Is the intake more powerful than the out? Or is there more resistance on the out than the in? If you are drawing through a carbon filter with the same cfm fan as your intake then the carbon filter is reducing performance on your outtake and therefore your intake is more powerful. That is probably why the fan noise is increasing, your intake is trying to push more air in than your outtake is removing, causing positive pressure so straining the intake. Ideally it is something you want to fix if possible because it sounds like you are overworking your fans so they will die sooner. I have never tried one of these fans you have adapted so do not know the sort of pressures it can take or make.
Are you sure you need the intake? Could you not use a passive intake with some soft of light baffle to stop light leak?
I suspect you would be better with just the extraction. Intakes are needed when massive fans are extracting. Most small tent systems don't need intake other than passive and this is way smaller than those.

I like how you are adapting things to suit the different purposes!
With your carbon filter make sure they are full, no gaps for the air to avoid the carbon or it wont clean.

EDIT rather than taking out something you have taken time to fit, just try turning off your intake and shutting the door to see if that solves the problem
 
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Azazel35

Member
The fans are both the same. These fans/blowers came out of a over the range microwave. The exhaust fan I have wired on high speed and intake on low. I'm going try turning the intake fan off. But afraid it will get to hot in box. It's in my garage which is super hot. So I made a room under the stairs and ran ductwork from Ac to the room to cool it.

Box temp high gets 89 low 80

Wondering if I drill a hole in the top and make small filter to sit over it. If that would be enough to release more air out.
 

coreywebster

Well-Known Member
I don't think in a box that size your intake will reduce heat, it can only put in what your extractor takes out without creating positive pressure. Its probably adding heat at the moment because its overworked. See how it goes with it off. Some fans are just not very good at pushing or pulling air through resistance either(carbon) If it doesn't help turning it off then could you use both to extract?
Can you tell how much air is coming out of the extractor? If you can feel it with your hand put a joss stick in there and see how fast it takes the smoke away.
I really hope you find a way to get it perfect.
If all else fails I suspect you could fit a 4" inline in there like a ruck fan which is more than capable of drawing lots of air through those home made filters. They don't cost much and you can pick up second hand ones for very little on fleabay.
Good luck with it.
EDIT also consider a few PC fans to move the air around inside.
 
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Azazel35

Member
So I tried turning my intake off and box gets hot! 108f even made the room hot. So I turned it back on and ended up replacing the exhaust with another blower from microwave, this one is bigger. Temp is staying around 80-84 in day 77 to 78 at night. Humidity is 38 to 40. Still have little positive pressure but nothing like before. The first blower I had installed, the top from the box was pushing down on the blower which rubbed the blowers blade making them flat and smooth. So think I'm set. But debating on going back to cfl. This is going be the 4th time I have done my own plants. The best plants were my first when I was learning. Which I used cfl. Sense I bought the led grow light I seem to have slower growth and more plant health issues.
 

TassieConvict

Active Member
I guess one thing to keep in mind is that to get the most out of LED lighting you need a higher temperature anyway... Im a bit surprised its putting out more heat than the cfl's tbh, i have a similar LED from ebay and it puts out less heat than 3x 23w 6500k cfl globes (however i dont even know if my ebay LED will grow anything as i bought it then never used it lol). Have you had any issues with your LED burning plants? The cab design looks good, im looking forward to seeing how it goes
 

b4ds33d

Well-Known Member
Nice idea and execution man. I'm working on something similar, filtered intake from bottom, carbon filter exhaust out the top, using organic growing method, utilizing raspberry pi/arduino devices to control and monitor things, 4x4 grow area and t5s as I'm currently brokeish. I'm currently filling a notebook with designs and haven't been able to get one that I completely like yet. This is more a way to test ideas I have on growing.
 

shake&bake

Well-Known Member
I always remember reading that your exhaust has to be four times as powerful as your intake otherwise you won't get the proper pressure. They will just be working against each other. Just something to consider but I always mounted my lights in a separate room from the grow chamber or just make a false top to your grow box for your light, always worked for me
 

grouch

Well-Known Member
I would ditch the intake fan and make sure the intake holes are big enough to supply enough air for the exhaust. If you have even a slight amount of positive air pressure you will smell it once you hit flowering.
 

Lucky Luke

Well-Known Member
Im just setting up a fridge grow and playing with the intake/exhaust as well. Yours looks to be a bit more sophisticated than mine , especially where your light is concerned. (https://www.rollitup.org/t/fridge-and-led-spotlight.914650/)

Use a passive (no fans) intake with some sort of filter (for spores and dust and spiders etc). Gradually increase the size or number of intakes until u have slight Negative air pressure. Sounds like you have positive air pressure which i believe is bad.
 

Fikeman

Member
Yo Az. Nice clean looking setup! Looks like you thought it out before half assign it! So this is in your garage or under stairs? Question....how loud are those microwave exaust fans? Quieter than when in microwave? Never seen this before great idea.
 

Flyfusion

Member
Great construction!! I have one about the same size, and I was try to calculate how to use the right intake fan. Since my exhaust has a "zen" carbon filter. I was burning out fans every grow. Plus the air needs to be cycled every 1-3 minutes. So I just went with the passive intake. And a light trap. And now all is good!! I find it difficult to figure the CFM between two fans if one has a scrubber hopefully someone will sum that one up for me! Awesome work man!!!! Kudos! :)
 

Azazel35

Member
Yo Az. Nice clean looking setup! Looks like you thought it out before half assign it! So this is in your garage or under stairs? Question....how loud are those microwave exaust fans? Quieter than when in microwave? Never seen this before great idea.
Sorry for late reply, but the microwave fans are pretty quiet. Nothing like it sounds when it's in microwave. This is understairs in basement/garage. I run a box fan in basement by the door which blends in with the grow box fan sound. So if anyone comes over the sound is a box fan.

As far as the positive pressure it turned out to be to much carbon for the fan to pull through. I made new square box 1/4" thick, filled it up with about 1/8" of carbon. I had to play with amount of carbon to adjust negative pressure, cause actually had to much negative pressure. It would pull the door shut lol.
 

Walterwhiter

Well-Known Member
Nice cab man. Decent little piece of furniture too. I've been playing with the idea of a deep freeze or refrigerator stealth cab.
 

Nugachino

Well-Known Member
That's not necessarily a bad thing having the door pulled shut. At least you know there's good airflow.
 
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