To ventilate or not to ventilate....

Ok, I I'm new. I know this is already my second thread so I'll try not to sound like a needy troll.

As I mentioned before, I am using an old walk in cooler as a grow room. So of course, I am starting with the benefit of excellent insulation. With no ventilation, I know it would be easy to keep temps regulated throughout the year.

I live in a state with four seasons ranging from below zero to one hundred F. Humidity is wild in the summer as well. I only have a room air conditioner and space heaters for temp control. This seems like it would be impossible to maintain a temp for even a full day with any realistic outside air intake.

But if I keep it sealed, with only an exhaust, I'll have to enrich the air with Co2. All the reading I've been doing (other websites and search function here) makes it sound like this is going to be a challenge. I have a regulator, but not a bottle.

Is there a ventilation method I'm not thinking of here or is it really a choice between trying to "offset" the outside temp or sealing the room and pumping Co2?

Also, perhaps I should have thought of this before, but the A/C unit I have is the standard window model which blows hot air outside. I can't seem to find whether this air exhaust comes from the air it pulls from outside or inside the room. Either way, an A/C plus exhaust setup seems like I'll have two exhausts. Would I have to add some odor control to the A/C air filter?

I know this is a long post. Thanks for taking the time to read and I appreciate all the help I can get

how about two fans one in and one out ......

Depends, if your running 400W+ then I would definitely recommend it.

yea what lighting? soil or hydro?

You must live near me with temps and humidity like that =) An old walk-in, that's brilliant!

However, growing in a small enclosed space like that you are going to need ventilation and climate control of some sort.

What I'm trying to do (after stupidly trying to grow in the summer with no climate control) is to rely on the heat from my lights to warm my grow space in the winter. This might work pretty well for you, depending on how large your walk-in cooler is. I've got a small space heater on deck in case the heat from the lights isn't enough, and will be purchasing some heating pads (the kind used for germinating seeds) to put under my plants so the soil stays warm.

I would advise against trying to use your walkin cooler to grow during the summer, unless you're going to put an A/C in, but for the spring/fall/winter, you'll probably do just fine.

If the cooler still works..thats perfect environment,,just a lil fan circulating the air is all id put!If the fridge dont work,then youll deffiniteley have to do som veniting and ducting work to keep the right temps.

Thanks for the replies so far. I've been brainstorming a bit, but first I'll answer questions about my setup. I have a 400W ballast, which can use either a MH or HPS bulb. I'll use MH for veg and HPS for bloom. I'm using 6 hydro buckets w/ air stones and air pump.

The walk in itself is very well insulated. I'm thinking that if I keep it well sealed (except for exhaust), it should not need much influence temp wise. For instance, winter or summer, the interior is usually "moderate" if there is no climate control. This leads me to believe that perhaps I should take advantage of this and use a closed environment. Unfortunately, this won't be possible if it requires more money, since I've dropped all my cash on the light and system

Here's my latest idea (maybe stupid ha). The walk in is about 15' x 8' x 6'. Not much head room, I know, especially w/ 5 gallon buckets. I only have six buckets right now so I don't need nearly that much space. The walk in is visible to neighbors so smell cannot be an issue. Also, I'm concerned about making too much noise since it's just been standing unused for years and I really want to continue to give that impression. I'm looking for some type of non-translucent thick plastic sheeting which I can build a make-shift wall with. I would divide the cooler into three rooms. The entry, the grow area, and the back area. The entry will be empty. This is only there to allow me to enter the cooler without letting anyone see what's inside (even light will not be visible w/ the door open). Once I secure the door behind me, I can now enter the grow room. (perhaps I can add zipper doors after these thin plastic walls have been put in place?) So the grow room will have two "natural" walls (the actual cooler walls) and two plastic walls. Beyond the back plastic wall I'm thinking of using the back room to house the A/C and use a duct to feed cool air in from the back wall. Here's a rough diagram.

enter {growroom} A/C room w duct { and } = plastic walls
---------{---------------------}----------------------

If I use Co2 enrichment, does this seem like it would be as good or better than a room w/ air intake and outtake? With the space being so small (probably 5 x 6 x 6), I'm not sure how I could have air intake and outtake without plants being exposed temps and humidity which wouldn't be desirable.

Sorry to ramble. That's what I have to work with right now. If I'm headed in the wrong direction here, I would appreciate any insight. Thanks guys

purpdaddy said:

If the cooler still works..thats perfect environment,,just a lil fan circulating the air is all id put!If the fridge dont work,then youll deffiniteley have to do som veniting and ducting work to keep the right temps.

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The cooler does not work. It's just the original insulation. Do you think the insulation would make it more efficient to maintain a steady temp and humidity without being affected as much by outside environment?

growcannibis2 said:

The cooler does not work. It's just the original insulation. Do you think the insulation would make it more efficient to maintain a steady temp and humidity without being affected as much by outside environment?

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Yes, this is what they are made to do as many food service establishments have walk-in coolers outside the building.

doobnVA said:

Yes, this is what they are made to do as many food service establishments have walk-in coolers outside the building.

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If it's not a working cooler, the insulation will only help trap the heat inside.

You're going to need to ventilate (cool) it like any other grow.

If you cool the lights separately you could run CO2 - with the ventilation off - but it sounds like that's not in your budget.

Green Cross said:

If it's not a working cooler, the insulation will only help trap the heat inside.

You're going to need to ventilate (cool) it like any other grow.

If you cool the lights separately you could run CO2 - with the ventilation off - but it sounds like that's not in your budget.

Click to expand...

I have a CO2 regulator. I just need to buy a tank. I'm thinking that may be the best way to go. If I do run w/ co2 enrichment and exhaust, I'll just need to figure out how much CO2 to give them, how often, and how often to flush the air w/ the exhaust.

If I do it this way, I won't need an air intake though, right? I still plan to have an A/C outside the room being ducted in.

why dont you fire up the light for 5-6 hours and watch to see what the temps get up to. i think you may have humidity issues if its sealed up that tight. you might just need some passive intake vents.