positive pressure

Ok guys so I have a 9.5 x 9.5 x 6.7 grow tent. 6) x 600 w wing reflectors. 1) 14000 btu portable ac dual exhaust. Won't be using co2. My temps get to as low as 85 during so cal summer nights.

I'm only in veg now, so heat isn't an issue. What I want to do is bring fresh cool air from outside to help cool the room and at the same time bring fresh co2. I have a carbon filter inside the tent that just scrubs air right back into the tent (no duckting). At the moment I'm only exhausting the heat hose of my ac ,an I'm not using my intake. So what happens is that it sucks air from inside the tent causing the walls to suck in. What I did was sucked air from outside with a 650cfm fan. Then the walls pushed out ,like a balloon. The 650 fan was just an extra fan I had, but its to much. So my question is, will just getting a smaller cfm fan be enuf to keep my tent from ballooning or will it not matter and ballon anyway. If it does what size fan should I be looking for.

I hope that makes sense to you. Thanks.

85 sounds really hot. why push air in? trying to get increased airflow? cause if I were you; Id use an exhaust fan to pull the hot air out of the top of the tent and let the passive vents (I assume there are vents since its a premade tent) draw in the cooler air from the bottom? would help keep heat down as well as increased airflow. IMO get the hot air out, fresh air will fill the void naturally


and if you wanted 'fresh' co2 just get one of those cultivator bags. theyre cheap, and work like a charm in small tents. Id add a couple in a tent that large. best of luck!

Just buy the Speedster fan speed controller.

just pipe your carbon filter to an exhaust fan ditch the ac and cool the roomyour intake is sucking from if you exhaust the hot air through a carbon scrubber and replace it with cool air from outside the tent you should be ok as long as outside the tent is cool.... your carbon scrubber is useless when your ac is exhausting stinkey air... intake at the bottom passive exhaust at top hooked to srubber you want negative pressure in there so it doesn't blow out un filterd smell

just dont smoke crack

Yea that sounds like another option, to suck hot air from the top. But I though pushing fresh air from the bottom of the tent would both cool and bring co2. 85 was during summer at night, I hope the cooler nights along with my ac could bring it down to the 70s. But if it doesn't I would pull fresh air in. I just don't want the ballon efect.

you want passive intake and active exhaust, its the most effective way to remove heat. if your walls are getting sucking in you need to slow down the fan with a speed controller or get a smaller fan.

tusseltussel said:

just pipe your carbon filter to an exhaust fan ditch the ac and cool the roomyour intake is sucking from if you exhaust the hot air through a carbon scrubber and replace it with cool air from outside the tent you should be ok as long as outside the tent is cool.... your carbon scrubber is useless when your ac is exhausting stinkey air... intake at the bottom passive exhaust at top hooked to srubber you want negative pressure in there so it doesn't blow out un filterd smell

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Yea, your right about the smell. It is a concern but the heat is my first priorty. I just got the tent I was using the entire room but it was to big for the ac to cool it. So getting rid of it wouldn't solve the problem really. Summer was really bad in so cal but maybe cooler nights will make a differnce.

if your balloning your room your wasting your resources. active exhaust hooked to carbon filter passiv intake you do not neet to pump air in. if you are removing air then as long as there is a open vent at the bottom air will come on in to replace it. exhaust fan scrubber passive intake as long as your tent is in a cool room it will work perfectly and ha been for thousands of happy stoners for manny manny years exhaust through a carbon filter out the top passive intake at the bottom that is all.

vindzl said:

Yea that sounds like another option, to suck hot air from the top. But I though pushing fresh air from the bottom of the tent would both cool and bring co2. 85 was during summer at night, I hope the cooler nights along with my ac could bring it down to the 70s. But if it doesn't I would pull fresh air in. I just don't want the ballon efect.

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Ok so exhaust the hot air thru my cf, open the ports at the bottom of the tent and that should both keep my temps down an bring fresh air. but what if the room the tent is in isnt really that cool to begin with.

what is the temp of the room the tent is in???? like a bedroom or something

vindzl said:

Ok so exhaust the hot air thru my cf, open the ports at the bottom of the tent and that should both keep my temps down an bring fresh air. but what if the room the tent is in isnt really that cool to begin with.

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Yea its a bedroom second floor. so its pretty much the last room of the house to cool of at night. i run my lights at night.

I guess it could work after the roon cools down but the first couple of hours it might still get hot. Wich is still better then all night temps in the 80s.

What if i exhaust like you say, then buy a small fan to pull air just in to the room.

air will naturally pull into the tent without any other fans help you want to have a fan in toh room blowing over your plants but other than that you do not need an intake. its like if you take a plastic water bottle and suck on it it will colaps and if you put a hole in the bottom of it air will rush into that hole when you suck on the other ond of the bottle any oir removed is replaced by the hole in the bottom with no help its simple no need for it just a hole in the bottom of the tent and an exhaust at the top. fans don't cool air they circulate it so if your fan is sucking out your 90 degree air from the top and replacing it with 70 degree air at the bottom once every min. your room will be cooler.


if you mean a fan to bush cool air from the rest of the house into that room the tent is in then sure it will help anything to help keep that room cool will help keep your tent cool. that way your tent has negative pressure so if there are any leaks it will go through the carbon filter and not be blown out into the room and it will star at a reasonable temp in the tent.... if you have to air condition that room is way better bet than overheated ballon tent hot air out cool air in

vindzl said:

What if i exhaust like you say, then buy a small fan to pull air just in to the room.

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Yea thats what i ment. ok then thats what ill do . thanks for the help you kept me from spending more money.thanks again.

money money money... your carbon filter sounded like a waste of money the way it was set up..... keep the room cool ventilate the tent and all should work out in the end... you can only move around hot air so much before you realize hot air is hot or something

vindzl said:

Yea thats what i ment. ok then thats what ill do . thanks for the help you kept me from spending more money.thanks again.

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Yea your right i was just going to put it outside the tent just so the inside of the house wouldnt smell.

sucking air through the tent is a much better way to go I hope it works out for you and may your nuggets be heavy frosty and plentifull

vindzl said:

Yea your right i was just going to put it outside the tent just so the inside of the house wouldnt smell.

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