This is a problem I should have remedied years ago.
My ac infinity fan exhausting causes so much negative pressure all the sides get sucked in and I lose tent space.
I’ve added an inline fan but it barely makes a dent in the pressure.
I also tried using clothes hangers in the corners but they immediately snapped when the pressure built up after zipping up.
What do you guys do?
I have the extra bar set for neg pressure… Gorilla tent… Works well.
My gorilla negative pressure kit was the best thing I’ve bought. Worked great to keep the tent walls from closing in on my plants.
I actually Emailed AC Infinity and asked why they didn’t offer a negative pressure kit available for their tents and got a very subpar response… felt like I wasn’t taken very seriously.
I’ve now resorted to two options. Either using other tent poles and using rubber garden wite to tie them in or opted to use my filter and fan outside the tent to blow fresh air into the tent and turn it into a tent Balloon(reverse that negative pressure.)
I just turn my fan down.
You could also match it to an identical fan for intake and then keep that intake one running a notch higher. But IDK, I do positive pressure
@beneficial are you using a carbon filter on the exhaust, and do you have all of the intake vents open?
If you have all the intakes open and can’t turn the fan down enough to stop that much negative pressure, try adding some ducting, or some 90° bends in the existing ductwork.
If all else fails, some bamboo with holes drilled in the ends, held up between tent supports with zipties will do in a pinch. Not too snug so you can slide the bamboo up and down if you need to get in the tent.
If the exhaust fan draws too much you can reduce the amount of air by putting a restriction at the intake of the filter. This is how it was done in buildings before speed controls came around. As long as you have enough airflow in order to control the temperature and humidity that is.
My Secret Jardin tent came with the negative pressure rails but you can do the same with simple DIY materials.
I like Gizmo’s idea of 3D printing brackets… 
Cheers
G
I’m def gonna add the high cfm kit to my Xmas list.
I guess there is a point to be made and that is how much air exchange do you need? There is only so much air exchange the plants need. I normally turn my fan up to the point where it starts sucking the walls in, if it goes in too much I fine tune it. That way I always have negative pressure but am not over working things. I do like the negative pressure kits folks are posting though. They would also come in handy for other things like clipping on a fan or tying off a plant.
@DougDawson This is something I have always wondered. I have run anywhere from insane (box fan taped to the side of a panda film tent, facing in with a 6 in exhaust fan, always on. Like a hurricane.)
to just passive (sitting in an openish room, little clip on fans or pc fans, but no real forced exchange) and both worked. The hurricane tent was definitely harder on the plants. Maybe a happy medium between none and all is the ideal haha.
Having said that, this is timely topic for me. I’m getting a new tent Saturday and have been thinking about this very thing. I’m imaging some emt conduit and zip ties, or paracord. I’ll post my hack solution here for all to see haha.
I think the general rule I have seen is air exchange every 5 min. Here is a cool calculator that can help.
I seen a hula hoop put inside around half way up from bottom and secure it on vertical poles that gives u little more side room an u move it up or down to keep around canopy height… And another thing did you open the bottom flaps and open bottom ports… Enjoy fam:trophy:
I don’t use a tent so bare with me but don’t they have vent holes for passive intake? I always go with negative pressure on my rooms so that smell can’t escape and new fresh air is constantly drawn in.
I am very scientific.
I turn up my fan until it sucks inward. Then I turn down my fan so it doesn’t.
Perfect.
2x2 lumber. I measure out the space in-between poles and then drill a hole the same diameter as the tent’s piping. I cut this down the middle resulting in a 1/2 “moon” as it’s 1/2 of the hole. This slots perfectly into the upright piping supports and is held in place with quick-ties secured via a small hole drilled in the 2x2 just behind the 1/2 “moon”.
Cheapest option I’ve come up with and it allows for multiple mounting points along the walls!
In the above pic you can see I use these braces to support supplemental under-canopy lighting (3000K led shop lights).
Yeah some fans those passive intake slots just can’t keep up with. Also another thing is you have to clean those slots people. They clog with dust etc from constantly filtering the air pulling in through the screen. They can look good and be clogged where there’s barely air moving through em.
I recently got an 8 in exhaust fan for my closet space I went tentless . Now when the fan is on I have that pull back opening the door
Lol 
