Venting this underground room.

So, after a Ton of thought, ideas, studying, reading, I've chosen to go under-ground. Here is the design and a little description. Some ideas on venting would be nice. The easiest way would be able to use 'ABS or PVC' piping, 4" or less........ Or, I can have box ventilation built to fit a 2x4 wall.

Veg room will be CFL's, bud room will be 6-600w cool hood HPS.

Now keep in mind, this underground unit WILL be SEALED TIGHT when door is closed.

Nobody? ........ Chirp.......... Chirp......

It's sort of absurd to expect to ventilate 10'x12'x10' (1200cu. ft.) and 6'x10'x10' (720 cu. ft) with 4"...anything. A full 14" (16" on center) stud space (54 sq. in. - roughly equivalent to one 8" or two 6" ducts) might work to take air out of the space but where does it go? Where is fresh air going to come from?

I certainly understand the attraction of growing below the frost line (particularly in AK) but if this space is totally buried (like a bomb shelter or something) then humidity will most likely be a problem (along with the mold/fungus that plagues dank/humid spaces). But then if it was actually a bomb shelter then it should already have ventilation/filtration better than you'd need. I guess you could (partly) get around the porosity of concrete by framing in a "room within a room". But if the walls in your diagram are already there... Of what materials are they made? Can you frame out "room within a room" walls? They'd help to keep temperatures more stable, anyway, but I still think you'll need gallons and gallons of dehumidification (good thing there are drains all over the place, eh?)

The more I think about your space, the more I think you may be better off sealing it up; going the "climate control and CO2" route. You could use a single stud space on either end (in and out) for the lamp heat in the flowering room (use a "T" or "Y" fitting to go from 6" to 8" and then into the wall on the way out; do the reverse on the way in). But the exterior walls are concrete... Dammit.

The real problem would be controlling climate in each grow space (as cannabis generally prefers slightly different conditions during veg and flowering). Either you could control the climate in the entire space using a heat pump and humidifier/dehumidifier (then use passive intakes and temperature-controlled fans in each grow room to spit "bad" air out to the big room) or you could put a heat pump (and other climate control machines) in each room. I guess you could get a two-zone heat pump and use each "head" for a room. If your condensers were in the big room, though, it would become a fungus factory in short order without adequate dehumidification...

Good Gawd, what a nightmare. I hope you're a secret millionaire so you can afford all the crap you'll need to make this work... But not having seen your space, and having no idea what the temp/RH are like in there without plants, I can't do much apart from spitballing ideas at you. In the end, you're the one that has to make this space work. I wish you much success.

not a nightmare at all. easy to fix. you say you want a sealed room but you want to air cool the lights.then do a real sealed room and forget air cooling, you can still use the reflectors or get parabolics, and just get a 18000 btu minisplit ac. my 12000btu easily handles 3k non aircooled,ballasts,dehumidifier, and feeds the veg room both equaling 110sf. no leaks to worry about, no odor problems. plus your plants will love the bulbs not being behind glass.

Ok, let me simplify........

The drawing I provided IS what I am going to build (start in a couple weeks), so it's NOT a pipe dream; just need to research it, and doing so.

So, I gave you the footprint, help me out. Ok, 4" intake/out take wont work; fine! Tell me what will. This project is in the 25k range, the price is not the problem. Setting it up to be completely auto, is the problem. I need to know, that's why I asked; go figure! The building will be underground, 4" slab, 6" concrete walls poured in "quadralock" blocks (2 1/2" styrofoam both sides).

Not hard to figure out, air comes in from 'outside', and then vents 'outside'.

I stated I could use "any kind" of venting; piping or tin vent style. Its not built 'YET' hence the question(s).

You have the dimensions, you have the understanding of what I'm trying to do; so why a long winded post of.............. ?

if you still insist on the venting, although a sealed room is beter, the box vent will be 3-4x as much volume as 4"pipe.

i would run a 10" or 12" in and out.

my only question is if you plan on running 3600w in your flower room...exactly how many CFL's are you running in your veg room? you might want to look into T5's or MH. might be a lot more efficient.

i also agree with above. get rid of the intake/exhausts alltogether and run a truely sealed room with Co2. if you completely seal the room then you may just want 2 4" exhausts that run at night to exchange the air in the room. i've seen a lot of growers switching to this model with good results. you would just need to make sure that your exhausts are filtered for odor.

a sealed room is a sealed room. there is no need to exchange air. you provide the enviroment. plants need light,food, water and co2 not fresh air they provide that.

@Superstoner & Scoobs.... I wasn't thinking about a "sealed room" that way; but now you've got me thinking! Looking up co2 info now.

So if the veg&bud rooms are sealed, I still have a 12'x16 that will need fresh air.

i strongly believe in a very sealed room. a small co2 generator like the minigen works great and burn times are very short. flower room and veg room combined are 11x10, i used 40+ tubes of caulk and 8gal of rubber paint. no odor, no noise.

I'm guessing you didn't even bother to read the entire post (which said basically the same things everyone since has said; except that I expressed concern for your budget and the actual end result being able to provide high-quality medication). You post a barely-legible "diagram" and few other considerations, then get snotty when someone actually gives you their ideas/opinions? You think what I wrote is long-winded? You've obviously never read an actual engineering report. And why are you asking questions I already answered? Wow. For someone begging for information, you sure come off imperious and dismissive.

I suggest that you hire HVAC/structural/horticultural engineers rather than relying on the advice of strangers who don't have all the variables. There are many variables that you haven't provided and much depends upon whether the structure is entirely below the frost line. If you seal the veg/flower rooms (which I recommended above) what you do with "the big room" depends on whether you "hide" the HVAC (heat pump) condensers in that room rather than placing them above ground. It could be more energy-efficient to keep them below ground but that room will need to be ventilated and dehumidified to compensate.

What I've been saying is that any decision you make in an environment like that is going to affect something else. You have a lot of decisions to make. Good f---ing luck.

Peragro said:

I'm guessing you didn't even bother to read the entire post (which said basically the same things everyone since has said; except that I expressed concern for your budget and the actual end result being able to provide high-quality medication). You post a barely-legible "diagram" and few other considerations, then get snotty when someone actually gives you their ideas/opinions? You think what I wrote is long-winded? You've obviously never read an actual engineering report. And why are you asking questions I already answered? Wow. For someone begging for information, you sure come off imperious and dismissive.

I suggest that you hire HVAC/structural/horticultural engineers rather than relying on the advice of strangers who don't have all the variables. There are many variables that you haven't provided and much depends upon whether the structure is entirely below the frost line. If you seal the veg/flower rooms (which I recommended above) what you do with "the big room" depends on whether you "hide" the HVAC (heat pump) condensers in that room rather than placing them above ground. It could be more energy-efficient to keep them below ground but that room will need to be ventilated and dehumidified to compensate.

What I've been saying is that any decision you make in an environment like that is going to affect something else. You have a lot of decisions to make. Good f---ing luck.

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Ahhhh, an "Engineer"; I should of know by the way your post was written. Anywho, we all know that engineers couldn't figure out how to find thier ass with both hands, (yes in my career I've delt with many corps. on projects, engineers should do the work before the design something.

As for the drawing I gave you, I can see it and read it plain as day on my iPhone, so not sure what your viewing issue is.

And thirdly, I WILL take a piece of your advise from the second post, to not "listen to strangers here on the site", I'll start and end with your advise. Good F!!!!ing luck to you, as well!

AKBud said:

Ahhhh, an "Engineer"; I should of know by the way your post was written. Anywho, we all know that engineers couldn't figure out how to find thier ass with both hands, (yes in my career I've delt with many corps. on projects, engineers should do the work before the design something.

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Yes, I can write English proficiently. Does that intimidate you? Even so, it's no reason to make a baseless assumption then follow up with a poorly-written excuse for a trite insult against an entire set of vocations/professionals. What an odd sort of bigotry (I don't think I need to explain where the world would be without "engineers" and other "intellectuals"). Your self-aggrandizing use of "the majestic plural" was almost charming.

I'm not sure what that last "sentence" is supposed to mean but the "design" here is more or less done. The diagram you posted is more than enough to work from if you were to provide actual information about the site and your goals (rather than vague pronouncements). I had presumed that you were dealing with an existing structure and/or serving as your own "architect" (which any reasonably bright person ought to be able to do). I figured this post was just fishing for free consultations rather than giving proper detailed information to the appropriate engineers/consultants. I can empathize with chronic pain making one a little cranky but you're just being a jerk.

AKBud said:

As for the drawing...not sure what your viewing issue is.

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So, because that ridiculous-looking (and tiny) font is legible on a glorified toy, you think it should look the same on any computer? Are you joking?

AKBud said:

And thirdly, I WILL take a piece of your advise from the second post, to not "listen to strangers here on the site", I'll start and end with your advise. Good F!!!!ing luck to you, as well!

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If you're going to attempt to quote me, have the decency to comprehend what I wrote. The only "advice" I actually gave was that you need to provide information about the site and precisely what you want to do if you want actual answers and not just ideas. I'd hoped for some intelligent discourse but all you've done is pour on that famous "Alaskan Charm" so you're getting nothing further from me (and, from the look of things, you're not getting anything from anybody else).

how are you powering it?