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cuisinartoh

grow room temp/humidity management

cuisinartoh
15 years ago

Hi all. I'm a newbie trying to grow tomatoes and salad herbs under HID in my sun room. The room is 7.5' x 15.5' x 7.25' (170 cu ft overall). There is a link to pics below. It's only March in Ohio but already I can see troubles with heat and humidity in the near future. As you can see, I have lots of windows and even french doors to the outside (not shown). My wife would rather I not use a fan and ducting between the lights. She likes to sit in the room and already thinks I've dorked it up enough! She suggested I get a small window AC unit to run in the room. Do you think that would work ok to control either the temp, humidity, or both? HIDs are 400w MH and 400w HPS with standard transformer ballasts. Using window fans isn't tenable since for security reasons or rain reasons.

Any thoughts or recommendations?

Thank you very much!

Here is a link that might be useful: My Hydroponics Page

Comments (12)

  • grizzman
    15 years ago

    I would recommend you take your plants outside as soon as weather permits.
    on the other hand you could rig up a 50 gallon barrel of water to act as a heat sink to absorb the excess heat while the lights are on and release it during the dark cycle. You'd need to do a little math to make sure you had the right volume of water. And you'll need to contemplate how to fashion the heat exchanger. And when its all said and done, it'll still look like a duct tape mechanic did it all. . .
    just put'm outside.

  • cuisinartoh
    Original Author
    15 years ago

    Then I have to deal with keeping the reservoirs cool by burying them or some other means. I'll have some traditional soil gardens going over the summer. So if I can't maintain an indoor garden through the summer, then I'll shut it down until the Fall.

    I can open the French doors that go into the house and use the house AC to condition the room. That's what I did before using the room as a garden room. If I could dump the excess lamp heat it might work but that requires ducting and fans :-)

  • grizzman
    15 years ago

    I don't know what size reservoir you've got, but last year I ran my unit outside and didn't have any problems. It generally held about 15 gallons. it wasn't buried or in any other means cooled and our temperatures are frequently in the mid to upper 90's through the summer.
    Oh! I was growing tomatoes. Not sure if different plants are more sensitive to water temp or not.

  • cuisinartoh
    Original Author
    15 years ago

    I'm growing tomatoes too and I usually keep 15 gallons in my reservoir as well. I have two of them I've built. Maybe I'll put one outside just for grins.

  • Karen Pease
    15 years ago

    That's what I did before using the room as a garden room. If I could dump the excess lamp heat it might work but that requires ducting and fans :-)

    Ah, thanks for reminding me again why I love my reflector-enclosed LEDs.... ;) 32 square feet, ~200W.

  • cuisinartoh
    Original Author
    15 years ago

    How much do you have in those LED lights? Be honest now :-)

  • Karen Pease
    15 years ago

    "How much do you have in those LED lights? Be honest now :-)"

    Probably about 26 square feet of plants. Most young, mind you :) There's a ~85W veg chamber (1000 blue LEDs, 100 red, 100 orange, all xmas-lights) and a ~110W grow chamber (100 blue and 100 orange LED xmas-lights, plus a UFO)

    Or did you mean price? About $110 for the veg chamber and ~$155 for the grow chamber, thanks to diligent ebay-watching. Sure, it's "ghetto" (wood lattice covered in aluminum foil with foil drapes, hanging on clothesline from plant hooks), but hey, it works. :)

    Here's one week's worth of growth on two pumpkin plants in the veg chamber:

    {{gwi:1001881}}
    {{gwi:1001883}}

    The tray behind those pumpkins was put into the chamber right before that first pic was taken; it had been under a single CFL, and had gotten pretty leggy. But even the leggy stuff has been recovering under the LEDs; check out the leaves on this lettuce after 8 days (note the pre-veg-chamber leggy stems):

    {{gwi:1001886}}

    When they went in, they had only one tiny set of true leaves and were lying flat on the ground.

    I'm documenting the process over on the Growing Under Lights forum; if you want to check it out, head over there.

  • cuisinartoh
    Original Author
    15 years ago

    Yeah I meant price. Sorry for not being more clear. I'm definitely interested in the future of LED lighting, but I just don't think they're quite ready for small-scale hobbyist hydroponics unless you're A) really interested in building your own solution or B) independently wealthy. :-) Since my ballasts were free (reclaimed industrial fixtures) I couldn't see not using HID.

    Thanks for the info!

  • grizzman
    14 years ago

    karenrei could you post a picture of the suspended lights? what kind of bulb spacing did you use?
    I noticed in the lighting forum you thought they were growing more up than out. could you lower your bulbs closer to the plants?

  • Karen Pease
    14 years ago

    It's hard to photograph them, as the monochromatic light messes with the camera ;) But here you go:

    {{gwi:1001888}}
    {{gwi:1001890}}

    No, only one plant is growing more "up" than out -- an okra seedling. Everything else is growing "out", quite nicely (see the pumpkins above for examples of one week's worth of growth). I'll be keeping an eye on the okra seedling to see where it goes from here. It's tall, but the stem is quite strong, so I don't think it's a problem.

  • grizzman
    14 years ago

    yes. okra is a very tall plant. they ran about six feet tall when we planted some in our yard one year.

  • Karen Pease
    14 years ago

    Thanks for the info; I've never grown okra before.