[djimb]

I'm in the planning stages of my new grow space, and I was hoping to get some input on my ideas.

I'll be building in my basement, where the temperature stays consistently at about 50F (10C). The lowest I've seen it get to so far is 48F when it's below freezing outside. I don't have a plan for additional heating just yet, but I figure I'll cross that bridge once the structure and lighting are set up. I'm hoping the heat from lights and possibly the use of a seedling mat might help keep things appropriately warm in there.

I plan to build a closet with two separate spaces behind locked doors to ostensibly serve as a tool/spare part storage space, with one side serving that purpose and the other side housing the grow.

The basement ceiling is ~6.5ft high (just under 2m). I was thinking 6ft would be a decent height for the closet. I would like to have a space for veg (seedlings/clones), males/open pollination, and a larger space for flowering out selected females. For these purposes, I'd like to use heavy duty 27gal totes for the veg and male space. For those I would like to use screw in LEDs or something similar with a low vertical space requirement. Remote ballast PLLs might also be an option. For filtration, I was thinking of individual, small carbon filters on PC fans.

The dimensions of the totes are 15.25in(h)x28.25in(d)x19.25in( w) (~39cm(h)x72cm(d)x49cm(w)) with a volume of 3.8ft3, using roughly the same dimensions for width and depth, this gives me about 3.5ft of headroom for the larger flowering space, with a volume of 13.2ft3

I'd love to use a 315w CMH for the larger space, but for now, I have an old Mars Hydro LED panel that I'll be using.

The thing that I'm having the most trouble nailing down is intake/exhaust for the whole space. I'd like to keep both cost and odor low, and I'm debating between exhausting to the room or building a void in the back of the closet to act as a plenum to recirculate air, or a small lung space that would allow fresh air and exhausted air to mix and diffuse out the back. Alternatively, I could just run a passive intake through the bottom of the closet and exhaust straight out the top. The first option would essentially act as a small sealed room and would most likely require CO2. The second one would also be more discrete, as there would be no noticeable breeze. The last option would probably be the easiest.

regarding fans, I'm unsure of what I would need for a space like this. PC fans seem like they might be the most quiet, but they may also be inadequate for the space

I'd love some input on this plan. If any of you see problems with it or have ideas of how it could be improved, I'm open to suggestions.

Also, I'm working on learning to effectively use Google Sketchup, so I'll hopefully have some basic 3D models to post up and illustrate what I'm talking about.

Thanks!

[Jellyfish]

One thing to consider as far as temps go- your lights aren't going to be on 24 hours a day, so what is going to keep things warm when it's dark?

[djimb]

That's a good point. The thought of staggering light cycles in the totes occurred to me, so that a pll balast would always be running and therefore generating heat, but I don't know how much heat they generate. I'll read up on that. I've also considered foam board insulation to try to retain heat. Once it's built, I'll give it a dry run for a week or so to get a feel for the temps inside. If I need to, I can always get a small space heater or possibly some heating wire that would normally be used for heated greenhouse beds. Something else to look into.

Thanks for pointing that out!

[Jellyfish]

"Alternatively, I could just run a passive intake through the bottom of the closet and exhaust straight out the top." That is what I'd do. In a space that small, a passive intake is fine. And like you said, easier, and if done right, quieter.

[Lemmiss]

You are lucky you have a problem with cold, and not with heat. Generally 1 degree cold approximately costs double in energy than 1 degree warmth.

With that being said I think that, if possible, you should invest in a small heating fan/element since maintaining an as possible stable temperature is important for, and greatly affects your yield. If you could just maintain 20c/68f or somewhere around there it would be great. if you have good insulation, and a larger waterreservoir(or any big volume of any-something leading heat) inside the growarea it could work somewhat as heat storage storing during day, and releasing during night(lights off), you probably too small for this though. I belive since you so small it will generally be hard storing temperature, and that you'll have too produce heat during lights off.

Also concerning your climate, I'm not sure, but I do belive a pc fan will have trouble/being too weak to draw enough air through any _effective_ carbon filter(An _effective_ carbon filter for _smell_(not same as for smoke n' stuff)) will also need some volume/take up space). I recommend you get a small version of what I think is called an "in-line tube fan", looks kind of like this:
https://www.google.se/search?q=In-Li...r5v_gBAxfzt_M:
Could easily be fitted with a carbon filter as well.

A tip for getting a quiet ventilation can also be to get a bigger fan than you need, running it on lower than max speed, that's at least how I do it.

Anyhow, if I were you... I don't think that space will give _too_ much smell. I think one of the more expensive/medium-priced ozon-generators(There are a lot of low-priced crap of these who promises a lot but does NOTHING!) could take care of that problem in full, they're pretty effective. I'd get one of those. No carbon filter. I'd do the ventilation using pc-fans. Also fit a small heating element running it when lights are off.

An interesting alternative considering heating would be to always grow from seed. Do one grow for seed and you'll have seed for a lifetime. But your grow must be of an "automatic"-strain. Then you just keep the lights on 24/7 giving you all the heat you need

Also, concerning smell... there _are_ varieties that smell very little compared to most.

[Jellyfish]

Look at Panasonic Whisper fans.

[djimb]

Originally Posted by Jellyfish

That is what I'd do. In a space that small, a passive intake is fine. And like you said, easier, and if done right, quieter.

So assuming that it's better to heat the air coming into the passive intake, I might keep a small space heater in the utility side of the closet, set up on a timer. I could also exhaust the air from the top of the grow side back into the utility side and put some holes in the back to allow air exchange with the rest of the room. Does this sound reasonable? Or is it needlessly complicated?

Originally Posted by Lemmiss

if you have good insulation, and a larger waterreservoir(or any big volume of any-something leading heat) inside the growarea it could work somewhat as heat storage storing during day, and releasing during night(lights off), you probably too small for this
though.
[...]
Anyhow, if I were you... I don't think that space will give _too_ much smell. I think one of the more expensive/medium-priced ozon-generators(There are a lot of low-priced crap of these who promises a lot but does NOTHING!) could take care of that problem in full, they're pretty effective. I'd get one of those. No carbon filter. I'd do the ventilation using pc-fans. Also fit a small heating element running it when lights are off.

Also, concerning smell... there _are_ varieties that smell very little compared to most.

While I really like the idea of thermal mass and passive heating, I think you're right. The space is too small, unless i built it with brick, and I'm no mason.

I like the idea of using an ozone generator too. I've read that they're good for fighting mildew problems in humid basements, so I would have a legitimate reason for having one in their anyway. The same can be said for a dehumidifier, which I anticipate I'll need in the summer.

Thanks for all the suggestions! I'll look into the fans you both suggested as well.

[Jellyfish]

'space heater in the closet' doesn't sound like a very good idea. Is it an indoor closet? Can you cut a passive intake from the heated part of the house?

[Gry]

Any time I see the word closet, this is what comes to mind:
https://www.icmag.com/ic/showthread.php?t=221265

[djimb]

Originally Posted by Jellyfish

'space heater in the closet' doesn't sound like a very good idea. Is it an indoor closet? Can you cut a passive intake from the heated part of the house?

Another good point. The space heater I was looking at was tiny and meant to basically act as a handwarmer on a desk, but a fire hazard is a fire hazard.

The room is a separate part of the basement under the porch. It's maybe 10'x6' (I'd have to measure to be sure), and the walls are cinder block. There's no easy way to tap into the central heating for the house, or to cut a hole to a heated room above it. 50f is fine for me to work in, and using a space heater to bring ~390ft3 of air up 20 degrees seems like it may be a pretty significant energy draw.

I'll look into the safety of heating wire. The kind used to defrost roofs and gutters should be designed for low temp increases and contact with water.

Thanks again!