problems about setting up my dehumidifier in my grow tent

Discussion in 'General Indoor Growing' started by charlesweedmore, Jun 1, 2009.

  1. Jun 1, 2009 #1

    charlesweedmore

    charlesweedmore

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    i have huge RH problem.i am 4. week of flowering and night time humidity is around 90% ! . there is no mold or PW issue -yet - .
    temp is around 83F and 60F at nights .

    i will buy a dehumidifier but i cant decide where i should put it .

    i have 1 active intake fan and it is 350m3 and pulls fresh air from my balcony to the tent.
    other 400m3 extractor is exhaust and extract the air from tent to outside of the house.

    total air movement is 350m3 / h . but the most powerful dehumidifier has 200m3 /H air capacity and 20L/ H dehumidify capacity.

    can the dehumidifier work in tent properly like this picture ?
    i also read that dehumidifiers warm up the grow room. is it true ? temp is already high in my tent ,it is around 80 - 85 F and i dont use CO2 . how much can a dehumidifier increase temperature in the tent ?

    i am very confused guys please help me.

    32.jpg
     
  2. Jun 1, 2009 #2

    Friend-of-a-friend

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    Charles, I know that heat is a byproduct of dehumidifiying the air. I run one in my basement and it is noticably warmer down there when running. As to how much heat you can expect, it prolly depends on how big a unit you buy and what setting you run it on (I.E. continuous run vs. low setting). Mine actually blows the heat produced out of vents in the back of the unit. Maybe you could set it up so that it vents the heat out of your tent somehow.......
     
  3. Jun 1, 2009 #3
    If your air is replaced at a sufficient volume as to totally replace the air in your tent at least 3 times per/hour, then I can't see the RH getting to 90% and staying there unless the air you're drawing into the tent is at 90% RH also.

    At 350 cubic meters per/hour exchange, what ratio of exchange is that to the total volume of your tent?

    If the air outside your building is less than 90% RH, then exchanging the air within your tent at a rate that causes a decrease in RH to match the outside RH would solve your problem.

    Are there other factors that prevent this?
     
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  4. Jun 1, 2009 #4

    umbra

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    this is why it was recommended to use an air conditioner over at the farm, because a dehum adds additional heat to the space. it was a good idea to try and dehum air before entering tent, but as you know with the air being outside, trying to dehum in open space is not practical. portable air cond is the next reasonable choice. it will need to be vented, of course.
     
  5. Jun 1, 2009 #5

    dirtyolsouth

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    It sounds like temps are as much of a problem as your humidity... A window A/C unit would keep temps down and probably take care of most of your humidity. If you're already in the 80's in your tent you don't want to run your dehum as it's only going to get hotter...

    Good Luck!
     
  6. Jun 1, 2009 #6

    Caretaker

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    That is a pretty high RH. Its gotta be coming from your intake or the exhaust isnt pushing enough. The fans can pushthe air you claim but is there anything stopping it from flowing freely. Something in front of the tubes or blocking a little bit. Plus is your exhaust higher up in the tent getting all that gunk out of there? I would put a intake on one side of the room and exhaust on the opposite other end. I am wondering if your air is moving around the corner of your tent and not circulating properly because of the position. The air in the far corner where the dehumidifier is sitting could have higher heat and RH because it is so far away from the fans. It would be more flow and distribution even having them on opposite ends. Do you read your RH from that corner also where the dehumidifier is?
     
  7. Jun 2, 2009 #7

    charlesweedmore

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    i live at somewhere near to sea. it is a coast ,like " island " . RH is very high here ,RH is about 90% in outside and it is roughly same in my house ,too .i use 600W hps @ cooltube .

    it sounds like a good idea to put Dehumidifier in a seperate room and pull from there .but there will be still too much air circulation in it .there is nothing different.if i put Dehumidifier in tent,active intake pulls 350m3/h air and if i put Dehumidifier outside ,the fan would still pull 350m3/h air .. it is same thing to keep Dehumidifier inside /outside of the tent isnt it ?if i put the Dehumidifier a different room,then it blows still warm air and i would still pull treated warm air to tent. what is the difference ?
    i am very confused guys.,

    i am sure i must decrease humidity or i will be screwed.
    For AC units, they cannot conduct a dehumidifier and a cooler at the same time.they will only work as a dehumidifier or a cooler at the same time.

    in addition to,i have high temp only for 3 summer monts but i have always high RH. thats why i dont wanna buy a A/C unit.next time i wont grow in summer .

    Well,i have still a high humidity and my dehumidifier will come in 3 days.
    i can run the dehumidifier only at nights,but this time the RH in daytime would be still high about 50%-65%.

    i dont know how i can down the RH in my grow tent :(
     
  8. Jun 2, 2009 #8

    umbra

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    air conditioning WILL decrease RH and lower temps at the same time:rolleyes:
     
  9. Jun 2, 2009 #9
    The only bummer is that it also adds to your electric bill. That's one of the prices we all pay for having as much world class weed to smoke as we want...

    Look at it this way; It's still less expencive than buying it a bag at a time. WAY LESS.
     
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  10. Jun 3, 2009 #10

    dirtyolsouth

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    Shhhhh....

    Be very very quiet...

    Listen! Do you hear all the words of the collective Marijuana Passion Forum echoing the SAME suggestion? Why yes, you do...

    A/C!!! :cool:

    Your high flowering temps are your main enemy... I know from the years of half-assed grows that I did before I saw the light... uh, dropped the green on an A/C unit. Temps are as equally important as lighting and fresh air to getting dankness. I used to grow the prettiest bud in town it just didn't have any GOO to speak of. As soon as I popped a portable A/C in a crawlspace grow many years ago and saw the results I saw the light... and it's a *cool* glow... If you have a window A/C in your room it will pay huge dividends in quality bud. I promise! Although elecricity isn't free, window units are much cheaper to buy than portables and they work better since you don't have to run a vent hose anywhere. If you drop the temps into the mid 70's using A/C I'm sure you'll get a handle on the heat and the humidity and you'll harvest mucho dankness.

    F.Y.I... a dehumidifier is very similar to an A/C unit... The dehum draws the air across cool radiator coils to condense the moisture for removal just like an A/C but the difference is the dehum then draws the air over warm radiator coils before exhausting the treated air back into the room. The theory is to put the treated air back into the space at "room temp" but that's not the case IME... My Whirlpool gives off lots of heat...

    Happy Growing...:cool:
     
  11. Jun 3, 2009 #11

    dirtyolsouth

    dirtyolsouth

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    Thanks SO much for catching that stoner slip... I really appreciate it! :rolleyes:
     
  12. Oct 9, 2019 #12

    ashelyrosa

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    Also i was setting up problem dehumidifier in my grow tent. After many research and professional suggestion, solved the problem. For help other grower i publish a post on my gardening blog about dehumidifier review and how to set up with many helpful information. For check my post, Click here.
     
  13. Oct 9, 2019 #13

    Danny73

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    I think that would defeat the purpose tho.... that “ hot air” is the new dehumidifies air not an exhaust like a window ac unit.
    Hope this wasn’t taken wrong just trying to help out I’ve been a hvac contractor for 25 years but haven’t been growing more then 4 months so I’d be happy to trade info lol good luck
     
  14. Oct 9, 2019 #14

    Ganjagrandaddy

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    i ran mine next to my intake fan and had it turned round. The idea was to pull the damper incoming air through the dehumidifier ( alongside room humidity too) and exhausted it back out the bottom vent facing back into the room. 2 birds with 1 stone so to speak. in a tent , it does the job well as they tend to be well below the room sizes they were intended for.
     
  15. Oct 9, 2019 #15

    Keef

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    Danny and Ganga -- Welcome to MP !-- I'm a water farmer and have nothing to add to your conversation but I wanted to welcome U to MP !--
     
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  16. Oct 10, 2019 #16

    Ganjagrandaddy

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    Thank you Keef. a warm welcome mate
     
  17. Oct 15, 2019 #17

    Danny73

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    Thanks man.... greatly appreciate it!!
     
  18. Oct 15, 2019 #18

    zem

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    Hello Charles. I live in a coastal region with high RH and I have a similar sized room. I place my dehumidifier right outside the veg box and it blows right over the plants. The unit itself produced significant heat when it was placed inside but it blows air that is not heated but it is its motor that heats up. It will lower the reading on your humidity meter but not too much, maybe 5% but the dry air that it blows is more than enough to keep my buds safe from mold.
    Where I live, split ac units come with dry mode and heat mode and the compressor is placed outside. On dry mode it will draw much less power than ac. I would have definitely chosen a split unit if it had not been for stealth reasons where i need the whole thing to be contained in one room.
     

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