My new home made grow box. Looking for opinions.

Discussion in 'Grow Room Design/Setup' started by quidado, Oct 28, 2014.

  1. So, my grow closet will soon be unavailable, so I've begun a grow box construction in my basement.
    The box will be a 6'x6'x6' room.
    Box Frame - 2x4x6' lumber
    Walls - Black/White Panda film stapled to wooden frame. Velcro sealing door section.
    110 CFM Bathroom vent fan, connected to about 10ft of ducting, connected to a Y connector venting out dryer vent. I suspect that 110 CFM may not be enough? Any input?
    10ft ducting going from bottom of grow tent(opposite end of exhaust) out of basement window to intake fresh air. 
    600 Watt MH/HPS with reflector. There is no cool tube. I will just have a fan blowing directly on the bulb towards exhaust. This worked fine in my grow closet.
    2 oscillating fans. 1 blowing on plants, one blowing on bulb
    Grow details:
    This is a 4 plant grow, with final pot size of 5 gallons. 
    Can anyone foresee any issue based on the details I provided? Any input would be appreciated. If you need more information or if I left anything out, let me know.

  2. Sounds like a good plan. I'd get a higher cfm fan and a charcoal filter. I was hoping there would be pictures! Ha. Post some if there are.
    I'm not too worried about the filter as dryer vents out to an end of the property that is pretty hard to access, and there's nothing near it.. but if for some reason the smell does become a problem, I'll certainly look into it.
    I'll post picture as I complete it. So far I've only got the bottom part of the frame done.. Once Ihave some real progress you'll see some pics! :)
  4. To calculate the airflow needed for heat control:
    CFM = 3.16*Watts/deltaT
    where deltaT = 10 *F

    So... With 600w you'll need ~190cfm to keep the box temp within 10*F of the ambient room temp. Looks like you'll need either another fan or a bigger one. Also, keep in mind that ducting and filters are going to lower your airflow due to the added resistance. There are equations for that but I'm too lazy to look em up right now. With fans, more is always better (within reason), I'd go with 400 cfm and get a speed controller and dial it back if you have to. Also, since you're tying into your dryer vent, you may want to get some backdraft dampers so that the dryer doesn't dump hot air into your box (or your box dump smelly air into your dryer), air is going to follow the path of least resistance.
    Good luck!
    Thanks! I actually ended up ordering a 190cfm fan, rather than just using 110cfm bathroom exhaust. If it ends up being too little, I'll figure something out...The ducting will be about 10ft long with just one 90 degree turn at the exit point.
    I was considering going with a back draft damper, but I thought it might not be totally necessary using a Y split. I'll test it out and if that's an issue i'll get one..
    Thanks for the info!
  6. I'm worried about keeping the room air tight... I want the air to be pulled in through a ducting that will be going outside and only through that... How much of a challenge do you think it will be to keep all other air out by simply stapling the panda film to the wood? Should I reinforce and maybe line with duct tape? or any other suggestion? My biggest concern will be the opening for me to get in and out of. I plan to seal it with velcro tape.. but I fear that might not create a good enough seal? 
  7. As long as your fan is set up correctly (pulling air from the box, blowing it outside), the box will have negative pressure. So when you open the door, air will be getting sucked in. I wouldn't worry too much about making it air tight, a few seams around the door isn't going to effect it too much. Path of least resistance thing again, just keep your intake duct as straight as possible and you'll be good.
    If your intake is directly from the outside, make sure to put a screen or something to keep bugs out. Also, depending on the climate where you live, it might get too cold in winter. You don't want to dump 10* air on your babies.
  8. Here's a couple pics. Got the top and bottom made.. just need to put up the walls. Currently only held together with 5 inch wood screws until I salvage some metal brackets from another project. They are holding for now, but I deff will need some reinforcing.

    Attached Files:

  9. Well if I were you I'd make/buy a carbon filter just in case. Remember, you can never be too safe. They're buildable for cheap prices :)
  10. Well here's my progress. Pretty much all that is left is to install the lights and add power.
    And yes that mattress is my fail attempt at adding a little stealth lol

    Attached Files:

  11. Straighter you can get that flex tube the easier it will be on your fan
  12. Did some test runs:
    Lights off. Passive intake ran out basement window to outside. Exhaust fan running full out dryer vent:
    50f with 100% humidity. There were puddles on the floor and drops all over the walls. I should have known better given the time of year.
    Lights off. Passive intake ran up to window, but not outside(window is old, and cold air still comes in a bit) Exhaust fan running full out dryer vent:
    63f with 50% humidity. Temps and humidity are almost perfect for night time conditions. Quite happy with how this turned out. I wouldn't mind the temp dropping a few degrees. Once I add the oscillating fans, that may do the trick.
    I've yet to be able to test with the lights as they are being used in the other grow room. Once the weekend arrives I'll pull them out of the current room during the dark period and test them for a few hours in the new room to see what conditions will be like.
    I'm hopping/expecting the temps to go up 10 - 15 degrees which would be ideal. Once I confirm my temps and humidity with both lights on and off, I will be making the switch to the new room.
    The 190CFM fan seems to be doing the trick. You can tell how well it's pulling air by how much the grow room walls suck in while it's running, and how much air is being shot out of the dryer vent. As someone mentioned, a damper will certainly need to be installed on the dryer side of the vent as there is a bit of a backflow happening (not much though)
    This should work well for the winter months.. Come summer time I feel heat may become an issue.. At which point I will most likely just air condition the basement.
  13. Are you going with a single 600w? In a 36 sqft space that's less than 17 wtts per sq foot. Nowhere near enough...
    Yes I am and I disagree that it's nowhere near enough. 
    It will work just fine. as it's currently working just fine in my current grow space of similar dimensions. Though, there are plans of adding a second 600watt in the future.
  15. Fair enough, sounded a bit shitty the way I put it. Around 60w per foot is seen as the sweet spot though. How big was the last space and did you use all of it?
  16. All good. I appreciate the input. My current grow space is 6x5. But I do have a divider closing it in on one side to be 4x5. I probably should have mentioned that, that is also my plan in this room until I get my second light.
  17. The room is done. All that is left to do is move the plants into it from the current room. Once it comes time for their lights to come on, I'll move them.
    \nLights off: 
    \n63f with 50% humidity.
    \nLights on:
    73f with 40% humidity
    \nConditions are looking pretty ideal with both lights on and off. I hope not much changes once I throw the plants in.

    Attached Files:

  18. Looks nice.
    I would jam 9 plants 5 gallon hydro in that bitch under 1,200 watts.
  19. Once I get some more lights, I'll do just that! :p
  20. I'm using a 1000-watt MH in a 4x5 space with 18 plants. Is this right? Could I have more plants? Should I have less?

    Sent from my iPhone using Grasscity Forum

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