Ventilator in small tent??

JackSkell

Active Member
no he doesnt, he has a filter attached to a hood but nothing attached to the other side of the hood. your best bet with this setup is gonna be going Filter>fan>duct>hood>duct out
 

JackSkell

Active Member
also if you do what i just said make sure you try it using passive intake(s) first, an active intake with that ventilation setup is likely to cause positive pressure.and if u have a vent port out the top of the tent (cant see from the pic) then use that one as your exit point.

btw you may have gone overboard on your tent if your just doing 1 plant which im assuming by the 1 bucket that you are. but i'm a micro grower :D it looks like that hood is at least 400w id be doing at least 4 in there if i was you.
 
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I have exhaust ducting, what I'm trying to achieve is exhaust the tent, cool the hood. I'm constricted with space as it's only a 2 and half feet by another two and a half feet, four feet tall. Is it possible to run the fan out of the tent, with some ducting conecting the hood. I wanted to go fan >ducting>hood>ducting to outside, but was worried the fan might start to wobble and become an issue. I felt zip tiring it wouldn't be sufficient t support considering the manufacturer gives you a bracket with pretty decent sized screws
 
It's a 400w dim able to 200, wouldn't four girls be much, I want to scrog them out I was considering doing a coco and perlite pot also
 

JackSkell

Active Member
whats the cfm rating on your fan? do you have a speed controller?
again in my opinion your best option is to slide that filter further back int he corner, attach the fan directly to it suck through the filter , blowing through the hood and out the tent, if you go filter>duct>hood>duct your gonna be running your fan on a higher setting to achieve the same effect as doing it the other way using a lower setting.

and thats a 4ft tall tent? you must be a midget then because if thats 4ft then your homes ceiling is only 5ft.. lmao im betting its a 6ft tent dude.
 

JackSkell

Active Member
i can comfortably fit 2 scrogged in a 2x2x4. but your tent is definitely 6ft dude. im basing it off the fact that i can see your walls and ceiling in the pic too, the average home has either 8ft or 10ft high cielings, and your tent goes atleast 3/4 of the height of your walls. 8ft wall 3/4 up would be 6ft. if you wanna keep it a smaller grow then id do 2 plants and run about 300watts of light so you can get the light a little closer to the plants than you would be able to with 400 and 300 is plenty for 2 plants. as for scrogging theres really no need to in a 6ft tent, just do some LST to get them to bush out, scrogging in a tent sucks if you cant get to one or more corners. if you LST them you can still spin your pots to work with them from the doorway. scrogging is best for microgrows
 
Lmao nah man it's not in a regular room all the other ceilings are normal haha but yea it's 4 feet not sure of the cfm rating, but with the speed controller on high it really cranks, pulls the walls Ina a bit so I test ran it on medium. I like the idea yiu have, in willing to give it a shot. But now I need to figure how to hang it. They recommend it's level and bolted how would I do that especially with space restrictions
 

JackSkell

Active Member
and also a good way to hang a fan in a tent without doing any shady rig up is to get a sheet of plywood, cut to fit the top of your tent, and place it ontop of the frame under the fabric, your light is being reflected down from your hood so the roof of your tent doesnt really need to be reflective and this goves you something to screw into, just make sure you screw into the board before putting the fabric of the tent back overtop of it, and clip the backside of the screws so that you dont poke unwanted holes in your fabric, of course if you prefer the reflective roof and dont mine a couple screw holes in your fabric then go ahead and put the plywood ontop of the whol thing and screw right in :p

and lol ok i trust you, like i said i was basing it off the walls and without knowing it was a lower ceiling it just looked taller haha. my current tent is actually 22"x22"x46" so just under 2x2x4 and like i said i can scrog 2 out comfortably and by comfortably i mean i can still move my hands through the branches under the screen, anymore than 2 and it gets hard to continue training them, sure they fill up the screen but they grow too high above it for the space. so yea you can scrog just keep it at 2 plants for managability. althought you have 2 opening corners to your ten so you could probably get away with 3 or 4 still! mine only opens one side so i do 2 side by side.
 
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JackSkell

Active Member
If your not sure of the cfm rating thats the first thing id be researching. its not just about getting enough suction its about getting the RIGHT suction. you only want to exchange the air in your room every 3-5 mins. and you want your air to move slowly enough over the carbon filter to be effective. trust me when i tell you that in small spaces proper ventilation is KEY, too much air circulation can be just as bad as too little. honestly with the info i have now im gonna say that Filter>duct>hood>duct>fan is best for you. your fan will probably be quite overrated for the space but giving it alot of resistance in the process of exhausting will make it managable. personally i achieve a modest negative pressure using very very very low cfms. my fan after resistance is running apx 4cfm. but i have a 13cft grow space, 4cfm after resistance is perfect for 1 exchange every 3 minutes. and i also run a vertical filter with fan directly attached venting out the top. no ducting.
 

JackSkell

Active Member
Yikes that is very overpowered for your tent. Running on the lowest setting you'd still be changing air 4 times a minute. Your tent is like 25cft. Since your pulling through a filter and hood you can multiply cft by 3 and that usually gives you a pretty close cfm for effective scrubbing and air exhange. In other words you ideally need about 70cfm to start with. And adjust from there. remember your only want to exhange air once every 3-5 mins. Now if your Temps are getting too high in the tent while running low enough cfm for proper air exhange. Then it means your hood requires more airflow to cool than your room requires for proper air exchange. At which point you may want to consider running your filter>fan>exhaust. And running a seperate fan just for cooling the hood.
 
Ok, I see it is very strong even when you lower it down. You said to only vent the room every 3 to 5 minutes, how would I do that do they have a special timer I can find
 

JackSkell

Active Member
You misunderatand. You don't want to only vent very 3 to 5 mins. You want your rooms air to be exchanged every 3-5 minutes. It means you don't want too much air movement. Replacing the air in your tent 5 times a minute will cause stress to your plant and not filter the odor out of you room. You want your exhaust fan to only spin fast enough that the amount of air it removes per minute is about 1/3rd of your tent size. I personally run my exhaust fan 24/7, others say you should have a timer to it so that it gets a break throughout the day but that's not a concern for me. What does your fan speed controller look like? Is it a rheostat style that has alot of adjustment from min to max or is it one that just has like a high/med/low setting?
 
High medium and low, growbright is the manufacturer . I do not understand though what you mean about venting every 3 to 5, how would you get a timer to run a fan 3 to 5 minutes off and on
 

JackSkell

Active Member
Lol again your misunderstanding. let me give you an example. My tent is almost exactly 13cft. I run my exhaust 24/7 at approximately 20cfm fan spec. but by the time to air actually passes through the filter and out the mouth of the fan the air is only moving about 4cfm. Because I have approximately 75% resistance from carbon/prefilter material. So for me running the fan 24/7 is proper ventilation because 4 cubic feet per minute is 1/3rd of my tents space. So it takes 3 minutes to exhaust 13 cubit feet of air and replace it with another 13 cubic ft. Does that make sense to you?
 

JackSkell

Active Member
I don't know exactly which fan you have but let's just do some quick guesstimation numbers. You said your fan has a max cfm rating of 420. So let's say that's what it spins on high. Medium speed is probably around 300 and low is probably around 200. Your tent is similar to mine but you have 25 cubic feet. 2.5x2.5x4=25. Let's guess that you have 75% resistance from your filter and all the ducting. so then you do your fans cfm-75%, so let's say your running on low and it's approximately 200cfm. That means by the time the air is pulled through the filter and ducting your fans real movement is 50cfm. But again you only have a 25 cubic foot tent. So you'd still be double your tent size meaning your exchanging air two times every minute. These are just number to show you how to do the math. If I was you I'd go ahead and hook it up like this. Filter>duct>hood>duct>fan. The more bends you have in your ducting is going to help you in your case. Once you have the ducting hooked up go ahead and run the fan on low setting and then go inside your tent and zip it up from the inside (if you can't do this then have someone else zip it up for you from the outside you need to have it closed to do this test) So from inside the tent with it zipped up. Hold a sheet of regular paper up to the bottom of your filter and see if it sticks to the filter from the suction. If it does not then try again on either side of the filter. If it does not then try the top, obviously the paper will probably stay up because it's being held up by the filter but make sure to actually see if it sucks to it. if it appears to be suckling but your not sure if it is or if it's just laying at the perfect curve to just appear that it is, then gently blow at the edge of the paper and see if it lifts up or not. If at any point the paper is actually suckling the paper down then you have too much air movement.

Now i want to clarify that this test is specifically ranged at your setup. This isn't going to be the way you test In every grow room. I'm able to calculate your space and vent needs because they're so close to mine. Your doing one plant like me in basically the same size tent. The difference is I have mine dialed in through testing. You'll have to do some of your own to truly find what works best for you. I've never actually owned an air cooled hood or a manufactured Carbon filter of my own, but ive set them up and know plenty about their resistances. but it's always been in way bigger rooms so honestly i might be slightly off with how many cfm you really need to pull through them in such a small area.but I'm very confident when I tell you that the most you need for your tent/hood/filter combo is like a 250cfm fan. But my personal opinion is more like 120cfm. always try to find then with (or just buy one) a rheostat controller (the spinning knob that changes the speed with every little adjustment of the knob instead of just low/med/high) and that will give you lots of room to play with and find what works best. If I was you I'd go to home depot/lowes and pick up a 4in 120cfm booster fan *they're cheap) and give that a shot. Worst case scenario it's not enough and you return it..
 

JackSkell

Active Member
lol thanks. i spent 13 of the last 14 years in cali, i had lots of grower friends and help them setup and redo their rooms all the time and of course attended the trimming parties :) i picked up a alot from those guys, and i never needed to grow myself because id usually get paid in bud for helping trim, there was atleast 8 different guys that id help out, one in particular i became goood friends with and he actually started giving me his runts so that's when i started growin myself, he ended up setting me up with a 200watt hood+ballast and 2x2x6 tent it was soo cool but i was very novice and disnt know shit about nutes, light heights, proper soil mixture, air movement, etc. so my attempts were pretty bad for a while lol. then i move to the opposite side of the country, been here going on 10 months, have only found 1 dealer whos bud i call acceptable but he charges 200 a half.... other guys are charging 150-160 a half and its always at least 40% shake, the nugs that are there are tiny little over dried, improperly cured popcorn shits.

one kid that i work with told me that he stopped going to his guy because he found out the guy was buying vacuum sealed lbs of the same garbage weed described above, and then would pour it into a strainer and RUN IT UNDER WATER to fluff it up. this story literally made my gut wrench and my anger ignite. that's when i decided i needed to grow for myself and set up my micro grow :)
 
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