Ventilation set-up question

Hey everybody...so my DIY vent fan just crapped out on me--worked great for what I was doing but now that it's dead it's time to get back to the drawing board.
FOr now, I'm growing in a storage room connected to my garage (the room is insulated). The dimensions are 5'x7'x8' (W x L x H) and the tent inside the storage room is 2x4x6 (so, yeah, i'm small scale, so max 6 gals going at a time). Now, my old lady has to use some of my storage room for, well, storage (and i do too, actually) so there's no hope of just pandafilming or painting white the whole room and getting rid of the tent. So, my current grow in there seems, environmentally, pretty decent...night time temps get a little low for my liking, and its been raining for a week so the humidity is fucked right now, but usually right between 38-59% (I'm in the last 3 weeks of flower). Here's the thing, though: The environment has begun to get a little less stable without my extraction fan and i've had to switch to leaving the tent completely open with just circulating fans in the tent and no extraction...also, when i did have the DIY i was just exhausting straight into the storage room and opening the door to the outside while lights were on to get some fresh air exchange.

So, there are two ways I can go forward with my next grow, one traditional, one more ghetto rigged...
I can just keep my circulating fans and open tent design, and then mount a small booster fan in such a way as to draw fresh air into the storage room near the top of the room and hope the circulating fans move air enough that its basically a way to add fresh cool air to warmer staler, less useful air. OR i can drop about 90 bucks, get a 400-530 cfm 6" vent fan and some ducting and run that jive to a hole in the ceiling or wall or something (any thoughts on that would be appreciated as well), then have the advantage of not worrying about opening the tent?

anyone see advantages/disadvantages here? any thoughts?

thanks everybody,
be easy,
Dr.J

No matter the route you choose, make sure your intake is coming in at the bottom 10% of your tent and the exhaust needs to be in the top 10%. If you have duct inside your tent and connecting to your exhaust port then the end of the ducting inside your tent must be hanging in the top 10% of said tent and the port can then be anywhere.

I would drop the 90$ on a 6" ventilation, even tho Im sure you could do with less with that size tent, maybe a budget 4 or 5" ?



dunno as I dont know what kind of light your running ?

but if its only for fresh air/co2 I would just a get a small 4" and use it to vent out the sealing and make sure to have a few passive intake holes the same size near the floor, maybe use any left over ducting from the ventilation/sealing to make the intake holes light proof with a few bends (work for me)

thanks for the tips guys, i'm doing 12 bulb PAR T5 lighting so not as much heat as full HID...this is more a question about the advantages/disadvantages of doing the grow in a closed tent in that storage room versus not worrying about keeping the tent closed and just making sure the storage room exchanges the air enough for the circulation fans to move fresh air to the plants...
like, for example, if i put an extraction fan on top of my tent and just vent into the storage room with the tent closed (i.e. no ducting, just mount the extraction fan on top of the tent and let it vent into the storage room, then also mount a booster fan to draw new air into the storage room, would that be alright? circulation fans would of course still be going on inside the tent.
or, contrariwise, I could do it up proper and connect my extraction fan to some ducting and vent it to the outside/into the ceiling of the storage room...
sounds like second option would be more sound and ultimately make it easier to control the grow...
thoughts?
be easy,
Dr.J

The second option is what you're saying slipon, right?

yes, let it pull air out of the room/tent, physics take care of the rest if your room/tent is`t 110% air tight it will automatically pull fresh air in from every hole/opening

Dr.J20 said:

thanks for the tips guys, i'm doing 12 bulb PAR T5 lighting so not as much heat as full HID...this is more a question about the advantages/disadvantages of doing the grow in a closed tent in that storage room versus not worrying about keeping the tent closed and just making sure the storage room exchanges the air enough for the circulation fans to move fresh air to the plants...
like, for example, if i put an extraction fan on top of my tent and just vent into the storage room with the tent closed (i.e. no ducting, just mount the extraction fan on top of the tent and let it vent into the storage room, then also mount a booster fan to draw new air into the storage room, would that be alright? circulation fans would of course still be going on inside the tent.
or, contrariwise, I could do it up proper and connect my extraction fan to some ducting and vent it to the outside/into the ceiling of the storage room...
sounds like second option would be more sound and ultimately make it easier to control the grow...
thoughts?
be easy,
Dr.J

The second option is what you're saying slipon, right?

Click to expand...

If you say your tent is in a closet, and you exhaust your air into said space, you will start "short cycling" your air and it could lead to issues (heat, humidity, mold). I am doing almost the same space, but no tent. I use a small 120cfm axial fan for the light and pull from the outside the closet and exhaust into the attic(cooltube) Then you can get a small 4" vortex fan with a carbon filter (4x14) for room exhausting and odor scrubbing. You want to be able to draw fresh air into the closet and with the exhaust leaving the closet from the tent, it will create a natural draw into the closet space as a whole including the tent with a couple of the lower passive intakes open. I think it will more than likely give you a better growing environment.

With it setup as such, you can actually control the temps better by taking the heat load of the light out of the equation for the most part anyway. Any supplemental heating, dehumidification can be done inside the closet, but outside the tent as it is the space you pull your fresh air from and leave all available space inside the tent for light adjustability and business purposes.

Peace and Great Grows

Asmallvoice

ASMALLVOICE said:

If you say your tent is in a closet, and you exhaust your air into said space, you will start "short cycling" your air and it could lead to issues (heat, humidity, mold). I am doing almost the same space, but no tent. I use a small 120cfm axial fan for the light and pull from the outside the closet and exhaust into the attic(cooltube) Then you can get a small 4" vortex fan with a carbon filter (4x14) for room exhausting and odor scrubbing. You want to be able to draw fresh air into the closet and with the exhaust leaving the closet from the tent, it will create a natural draw into the closet space as a whole including the tent with a couple of the lower passive intakes open. I think it will more than likely give you a better growing environment.

With it setup as such, you can actually control the temps better by taking the heat load of the light out of the equation for the most part anyway. Any supplemental heating, dehumidification can be done inside the closet, but outside the tent as it is the space you pull your fresh air from and leave all available space inside the tent for light adjustability and business purposes.

Peace and Great Grows

Asmallvoice

Click to expand...

I think i get what you're saying, however, if i keep the tent closed, exhaust to the ceiling of the room and make sure the room, instead of the tent, is always supplied with fresh air, wouldn't that avoid the short cycling? I'm thinking that the negative pressure created within the tent would allow the extraction fan to create passive intake of the air that's being pumped from the outside into the room...the exhaust fan would essentially draw air from the room through the intake openings, seams, etc. and exhaust it into the ceiling....sound good guys?

Get the fan. It is def worth it!

yea agree, even a small budget 4" axis fan and some 4" ducting

Slipon said:

yea agree, even a small budget 4" axis fan and some 4" ducting

View attachment 2485329

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this sounds most promising...i'll do this for sure regardless of whether i get the 530cfm....which i will get haha
be easy
Dr.J

Dr.J20 said:

I think i get what you're saying, however, if i keep the tent closed, exhaust to the ceiling of the room and make sure the room, instead of the tent, is always supplied with fresh air, wouldn't that avoid the short cycling? I'm thinking that the negative pressure created within the tent would allow the extraction fan to create passive intake of the air that's being pumped from the outside into the room...the exhaust fan would essentially draw air from the room through the intake openings, seams, etc. and exhaust it into the ceiling....sound good guys?

Click to expand...

get a wall vent and put it at the bottom corner of the room for passive air intake.