Positive or negative pressure in my 48x 48x 80x tent

[Sbev]

I have a 400 cfm and a 435 cfm smell is not an issue. All i keep reading people's reasoning for negative pressure is to keep smell in. Idc about smell, what is better for my plants is all i care about. Please help.

 

[TheRoach]

I would say negative pressure, but you can try either way and switch the fans later if it doesn't work as expected. Good luck

 

[JuanCarlos]

Negative pressure. If you are pumping in more than you are sucking out then you have stagnant air building up. I would actually get fan controllers for both and run them slower. I believe it's said that you want to exchange the air in your grow once every 3-5 minutes (going off memory here, do some digging to find the exact specs, although it is misquoted somewhere on this website as 3-5 times per minute). Your space is 106.67 cubic feet, so those fans will exchange the air about 4 times per minute which I have read can have negative effects on the plants.

 

[TheRoach]

I always hear conflicting opinions about how often should air be replaced. I always go by every 3 or 5 mins, I think 3-5 times a minute is way too much (while I guess it wont hurt, I think that's way too much for my grow area)

 

[vastok]

neither ..as both methods create un necessary wear and tear on the tent, keep it cool and have a passive inlet too

 

[JuanCarlos]

400 cfm fan with passive inlet will be create negative pressure on most tents.

 

[TheRoach]

neither ..as both methods create un necessary wear and tear on the tent, keep it cool and have a passive inlet too

I use passive intake but didn't know active intake would wear the tent. Mine is made of cordura fabric, very resilient... can you elaborate a bit on this please?

 

[Sbev]

Well its still under my 30 days i could return one and get equal cfm on both if that is ideal. I also am going too be running co2 if that takes effect on anyone's opinion.

 

[indica vet]

it doesnt really matter if you run natural,positive or negative pressure

 

[Sbev]

it doesnt really matter if you run natural,positive or negative pressure

I realize the positive negative or natural wont actually effect my plants too much itself, But temps will. Trying to create an optimum climate & control within my tent is my main priority with summer ahead.

 

[JuanCarlos]

Seems like it may be best to put the opinions aside and sift through some FAQs and books. There are some great books out there, this site has a great FAQ section, so I would look into that.

 

[Tead]

Keep your needs in mind. For instance, if you were trying to control odor, you'd want negative pressure so none of the odor gets out without being filtered. I, on the other hand, don't care about odor but have a very hot environment and pumping AC air into the tent is required. I keep it "inflated" with an open vent at the top and AC input at the bottom plus a box fan inside to keep the air moving.

 

[Sbev]

Thanks. I also dont care about smell and my grow is up strairs in a hot room i just hooked up airflow from my ac to my tent. Dont really like to keep the ac on but i guess ill have to change that.