1. We are currently experiencing issues with viewing and uploading images, our team is working on the issue.
    Dismiss Notice

Fans for Small Stealth Grow Box

Discussion in 'Indoor Growing' started by w33dh33d, Jun 28, 2007.


    w33dh33d Active Member

    So I went and bought some fans for my stealth grow box. See my grow journal link on my signature below.

    I bought two 80mm fans which fit snugly over my 4" holes.

    There is one at the top for exhaust (hot air at the top), and there is another one at the bottom for intake. It is conveniently located beside my A/C duct.

    The fans are rated at 12V, 500mA, and shuffle about 35 cfm. This is a complete exchange in my 2x2x4.5 box about every 30 seconds. Ideal:mrgreen:.

    I bought an unregulated 12V power supply for them and rigged them in parallel. The power supply can handle 1A, so this also is perfect. I suppose if I wanted to get anal about it, I could build a regulating circuit for another few bucks, but at 16V, I'm pretty sure the reduced lifetime of my fans will not occur during this grow. I may even upgrade in a couple months to 100mm (4") fans.

    I plugged it into my timer circuit, so the intake and exhaust fans will only go during the daylight hours. I wonder if this is an ok idea, or if they should be ventilating 24/7.

    I also bought a $5.00 desk fan to keep the air circulating inside the grow box.

    Enjoy the pics... comments welcome!

    Attached Files:


    gillard Active Member

    very nice im setting up a space almost the exact same and was wondering how many plants are you currently/planning to grow in there?

    UserFriendly New Member

    if you keep the fans on 24/7 you won't have to worry about mold.

    w33dh33d Active Member

    Hi there, it's going to be a one plant operation for this round. If this plant is nice, I'll probably clone and grow more in the space. I have a feeling that I can grow 1 big fat one, or 4 tall skinny ones in there. Check out the box at http://www.rollitup.org/grow-journal...box-build.html

    UserFriendly, good idea about the fans. I will be leaving them on 24/7.

    kalm325 Active Member

    where did u get those fans and for how much

    w33dh33d Active Member

    Sorry for the late reply.
    I got the 12VDC fans at an electronics supply store. They were only a few bucks. The wiring is low gauge telephone wiring (or something similar, just read the writing along the side of the sheathing).

    I also got that same power supply there. It's an unregulated 1A - 12V power pack. I just snipped the ends off and used my multimeter to determine which wire was postivie and which was negative.

    hehehe3 Active Member

    I don't know if you are lining the interior of your box with anything, but 1) reflective plastic mylar, 2) shiny white paint, or 3) aluminum foil will all increase the effectiveness of your lighting. (I use bubble-wrap insulation coated with reflective metal similar to aluminum--available at hardware stores).

    w33dh33d Active Member

    This posting was from my first grow. I'm on my second generation grow, and am now using mylar. I notice a HUGE difference already.

    w33dh33d Active Member

    And the original fans are still doing the trick.

    dopeadope Member

    What are u using for the power supply? can you post a pic? or send me and email?

    blazingtarm Member

    can you please elaborate on how you set up the fan rig? i wouldnt know where to start with the electrics.

    wtfyouppl Member

    Blazin: With my grow box I also used computer case fans (2x 120mm) connected to an ac to dc power supply (used similar to a cell charger). Biggest key is to make sure your fans don't use more amps then what the power supply sends; plus try to find the similar voltage if you want longevity of the motors in the fans.

    If you need more information then that or like to know any more specifics then that shoot me a mail. [email protected]

    secretforestgarden Active Member

    I need TRUE stealth for my grow: no odors, no light, negligible sound.

    I'm doing a 24" PC case grow with CFL, 35w HPS, and LED. Needless to say, heat can be an issue.

    So, I needed to find fans with the lowest decibel to CFM ratio. I've been doing PC repair for years now and have a decent knowledge of what one would need for effective PC cooling.

    Thus, I came across a PC fan company by the name of SilenX. They advertise the lowest dB to CFM. Great!

    I am moving around 110 CFM out of my PC case with virtually no noise. My humidifier in my room (for the cold season) is much louder than my case. They have a 120mm fan that moves 90 CFM with only 18 dB.

    Their fans are also a great price. One can fetch an 80mm fan from TigerDirect.com for around $10. I've bought really high-end Nexus fans in the past--which are great, quiet fans--but they are more expensive and have a worse dB to CFM ration than SilenX.

    One can also buy an AC-to-DC adapter for said fans from TigerDirect as part of a SATA-to-USB external hard drive adapter kit since hard drives and case fans use the same 5V/12V power system.


    countbongula420 Active Member


    secretforestgarden Active Member

    Sorry man, it's a little more complicated than that. Computer Fans are DC power and the power that comes out of your wall is AC.

    First off, for another dollar you can get this:

    Which is the SilenX iXtrema Pro 18 db 90 CFM which pushes out more air than the one you posted and does it with less noise--and they're really durable.

    Secondly, you're going to have to get an AC-DC adapter (you can use one for all of your fans--just takes some splicing). An AC-DC adapter has a voltage schematic, usually on the back. You can sometimes buy them standalone like this: http://cgi.ebay.com/EXTERNAL-AC-POW...ultDomain_0?hash=item439d881b50#ht_500wt_1182

    --for pretty cheap.

    There are two dominant schematics when it comes to AC-DC hard drive adapters (hard drives and fans use the same voltage)--if you plug it in, it might work right away. Otherwise, you might have to switch a wire around when you're splicing, the negative, if I recall correctly. DC is really safe, so you as long as you don't short it out (touch the positive to the negative), having it wired incorrectly will just make it so the fan doesn't run--you won't hurt the adapter or the fan and you can try wiring it up again to the adapter output.

    BTW, whatever fan you get, get a SilenX. They're truly the best on the market for CFM and noise and they're about the same price as most run-of-the-mill fans.

    Cheers and good luck!


    countbongula420 Active Member


    secretforestgarden Active Member


    countbongula420 Active Member

    So do you think any silenx fan will plug in to that? I dont see why they wouldnt make the controller work for all of thier fans lol

    secretforestgarden Active Member

    Great question. All PC case fans have somewhere between 2 and 4 wires. They at least have the positive and negative hookups and potentially a ground (not important) and maybe some kind of speed control wire (also not important). As long as your positive and negative on the fan are hooked up to the positive and negative on the adapter/speed controler/whatever you use, you'll be in the clear. That's why I like an external hard drive power supply because I don't have to deal with ground or speed control wires (and it's cheaper)--but it's all preference. Some people even rig up phone chargers for their PC case fans. Most of the time, generally, whatever you use----you're gonna have to splice a wire or two.

    Hope this helps!


    countbongula420 Active Member

    I donno...with this controller it looks like you can just plug in the fans and go! I dont think splicing will be required. I guess we will found out soon enough.....

Share This Page