To Push or To Pull? Now that is the question

[AOD2012]

ok people, i am just throwing this question out there because i am getting reading a lot of conflicting things on here. which is better to do when running c02, to push the air or to pull it? ive been told that pushing is better because it causes less stress on the fan since it isnt pulling the hot ass air through, and also the fact that it creates negative pressure(i believe im right here) which in turn wont suck that c02 through the lights and what not. and then other people are telling me that pulling is better. so can as many people who care or even better if you have had experience doing both and have actual experience and know which one works better i would be much appreciated. thank you very much for any input people.

 

[bterzz]

Push!

Why pull? You have two very good reasons to push, but none for pull other then "people tell me its better".

Pulling the air with any air leaks will suck your co2 enhanced STINKY air right out of the room, no good for your enviroment or your security.

Pushing the air will blast the air OUT of the air-leaks, rather then pull them in... No co2 getting sucked into hoods, no stinky air leaving the room.

Best of luck!

 

[AOD2012]

thank you very much bterzz, i have a very big problem with not having confidence in myself and unfortunately the second i hear something that isnt what i was thinking i start to doubt myself. even if i have good reason i still do. bla bla bla thanks a lot just what i needed to hear.

 

[ourcee]

if you have leaks, and are using c02, be prepared to get no benefit all at great cost!

pull air

if you PULL air through a tube and it has a pinhole, you are pulling stinky (possibly co2 infused) air through that hole, but regardless that air you are trying to move, its goin out.

if you PUSH air thru, it pumps it out all those small pinholes back into your garden, thus making your ventilation THAT much less effective.


always put your fans last in line for for your air.

btw pulling creates negative pressure, i.e. the room will try to suck air in through any hole possible

by pushing air, you create a higher pressure in the room, thus forcing air OUT every hole in the room. less effective in controlling your environment imo.

so pull=lower pressure in the room, pullin air under the door into the room, keeping smell IN (should have carbon filter/fan last in your chain of airflow)

push=higher pressure that will push smell/c02 out any little crevasse it can find (and under your door, along with that stank)

 

[growinthehills]

Push!

Why pull? You have two very good reasons to push, but none for pull other then "people tell me its better".

Pulling the air with any air leaks will suck your co2 enhanced STINKY air right out of the room, no good for your enviroment or your security.

Pushing the air will blast the air OUT of the air-leaks, rather then pull them in... No co2 getting sucked into hoods, no stinky air leaving the room.

Best of luck!

i haven't delt with CO2 but if your worried about smell then pulling is better in my experience. If your pulling you will pull outside air in and keep all the stinky air coming through you carbon filter(that is if you have your exhaust fan connected to you carbon filter). If you don't need to worry about smell pushing is better. it helps keep bugs out because there is positive pressure pushing air out of your room, if you have any leaks. I know this is about CO2 which i have no personal experience with so if this is of no help then completely disregard my post. I hope you get the advice you need!

 

[AOD2012]

ahh this is why im so confused. right now i am pulling air from outside the room through my aircoled lights and out an exhaust. i am just running my carbo filter in the room to circulate the air and clean it inside. i kind feel like pushing would stop the stinky air from going out the exhaust, and that is the last thing i want to do becase i am exhausting out of an old dryer vent. i am pretty sure that i have the room sealed pretty well, but if anyone else is like me, everything that can go wrong will, gotta love murphy's law. so in theory if the room was really and truly completely sealed, i do feel that pushing would keep the smell from exiting my exhaust and keep c02 inside awww man my head is spinning.

 

[bterzz]

i haven't delt with CO2 but if your worried about smell then pulling is better in my experience. If your pulling you will pull outside air in and keep all the stinky air coming through you carbon filter(that is if you have your exhaust fan connected to you carbon filter). If you don't need to worry about smell pushing is better. it helps keep bugs out because there is positive pressure pushing air out of your room, if you have any leaks. I know this is about CO2 which i have no personal experience with so if this is of no help then completely disregard my post. I hope you get the advice you need!

What?? He's talking abut ventilating his lights.

You want to PULL through a carbon filter, ..

Push through the lights.


EDT: You're talking about cooling your hoods, right??

 

[ourcee]

What?? He's talking abut ventilating his lights.

You want to PULL through a carbon filter, ..

Push through the lights.


EDT: You're talking about cooling your hoods, right??

either way, seal the hoods/ducting up good and PULL, if you DO happen to have a pinhole, it will pull it through, rather than bump that hot ass air you are trying to vent out, back into your grow room,

i dont know where you live, but if you have the need to vent your hot air, might as well make it as effective as possible so as to reduce your electricity usage as well as wear and tear on your equipment.

 

[AOD2012]

yea, just talking about air-cooling my lights.. i have them on a closed circuit pulling air from another room in the basement and out the dryer vent. i have my carbon filter just chillin pulling the air through the filter just recirculating in the room.

 

[ourcee]

ahh this is why im so confused. right now i am pulling air from outside the room through my aircoled lights and out an exhaust. i am just running my carbo filter in the room to circulate the air and clean it inside. i kind feel like pushing would stop the stinky air from going out the exhaust, and that is the last thing i want to do becase i am exhausting out of an old dryer vent. i am pretty sure that i have the room sealed pretty well, but if anyone else is like me, everything that can go wrong will, gotta love murphy's law. so in theory if the room was really and truly completely sealed, i do feel that pushing would keep the smell from exiting my exhaust and keep c02 inside awww man my head is spinning.

if its 100% perfectly sealed, it doesn't really matter pushing or pulling, the fact of the matter is that you probably wont get absolutely 100% perfect seal. even that 1% is worth attention.

if you use c02 and have a very very CLOSE to perfect seal, you can push air, but on the off chance you get positive pressure in the room, it will leak c02 and smell thru any porous area.

if you pull it through in the same instance, you MIGHT remove SOME parts per million, however if you have a grow large enough to benefit from a full room of c02, and its sealed to the best of your capabilites, then you would lose a negligible amount of c02 while keeping any extra c02 or smell you would have lost under the door, inside the grow instead.

either way, you seal it up really well and have the air coming in -> going over lights/hoods -> going out, all without interacting with c02 enriched air, then you are fine with pulling or pushing. the temp has no influence (unless you are talking like 120 degrees+)

 

[growinthehills]

What?? He's talking abut ventilating his lights.

You want to PULL through a carbon filter, ..

Push through the lights.


EDT: You're talking about cooling your hoods, right??

THat makes more sense then if your talking about cooling your lights then with CO2 I will sit back and try to learn a thing or two. sorry for any confusion I caused. I would say I don't know shit...

"if you PULL air through a tube and it has a pinhole, you are pulling stinky (possibly co2 infused) air through that hole, but regardless that air you are trying to move, its goin out."-ourcee

tI don't Know shit. sorry I even posted. i didn't understand the original post... my bad

 

[bterzz]

Ourcee, you dont think that if there is a "TINY pinehole" (Like you are saying), and you are PULLING that air from the room, into the pinehole, out of the room...that air will stink up everywhere it exits?

Currently I am pushing. One of my three hoods is not completely air-tight. 2 of the 3 are.

If I was pulling air through that non-air tight hood, and my room had co2, not only would i be pulling my co2 out of the room, I would be pulling stinky air out with it...

Since I am pushing, no air will be leaving the room, and I will be doing nothing but adding air (whatever temperature it may be) from the outside into the room.

EDIT: Are you saying because he is using co2, any air that is blown into the room create to much pressure? That makes sense, very debateable.

 

[AOD2012]

hey bro this is exactly what i wanted, as many different opinions on the matter. my hats off to everybody who took time out to respond. thank youse all

 

[growinthehills]

positive vibes and education to all who are willing to receive... Peace and stay Irie. I hope that good discussion keeps rollin on

 

[AOD2012]

thank you all very much. hitting the sack gotta be up in five hours for work. i sit down at the computer and next thing i know 3 hours have passed. hopefully more is added and more people benefit from it. peashout

 

[REZDOG]

The closer your fan is to the coolest-sourced air,(inlet or outlet) the more efficient,pushing or pulling.
The shortest most efficient way betwixt two points is a straight line,as well.
"Pull" through carbon,always,imo....

 

[ourcee]

what bterzz is sayin is correct too. if theres a tiny hole like I was saying, you'd suck smell/co2 out the hole and vent it out, if you sealed VERY well, the volume of air, the volume of c02 and stink, would be very very small, but still an amount.

on the flipside, if you pushed air, it would come thru the duct, out a pinhole (in this instance) and get pushed out into your room, it wouldn't VASTLY increase pressure, however 18 hrs of constantly adding a few liters per minute of air WILL increase pressure and push some smell/possibly c02 under doors and whatnot,

if you pull the air, it would suck air under the door INside the grow.

I'm getting on a tangent, if you push, it will get that air back into the room and circulate it around, if you are running a carbon filter freestanding in the room just scrubbing the air and not venting it, you shouldn't have any problems pushing or pulling and having stinky air escaping (that being said you have a big enough carbon filter) because if it gets sucked OUT the room through a pinhole (pulling air), then its non stinky, minorly c02 enriched air,
if you are pushing, its gonna put a lower ppm air into the room along with outside air being added to your already being scrubbed room.

neither of these are really problems though as your plants will consume co2 in a sealed environment very fast. (given you have enough of them that is).

 

[Lazyman]

Also, almost every fan in the world is more efficient at pushing air, not pulling it. Bterzz got it right, besides, any tiny leaks it forces air out of should be enough air to pressurize a coffee can, let alone a whole freakin grow room! Closed loop light cooling (pull air from outside with fan, through simple bug filter, push through lights, then back outside) should affect the pressure in the room a bit anyway. Use carbon scrubbers with no ducting so any leaked air is odorless too.

 

[mayorofthdesert]

A safety note concerning pulling - if you subject a flex duct to too much negative pressure it can create problems. I don't know if they can collapse per se, but my fan pulled some of the clear inner lining off my flex duct and basically sealed the duct shut. I came home from a week away to 100 degree and 90% humidity cabinet. The fan in the attic was chugging away like a champ, but hot as hell.

*My mistakes that caused this to happen: I had something semi-blocking the cabinet's intake (not on purpose obviously) and the flex duct had been pushed, pulled and shoved through tight spots. I'm guessing there was some breach in the foil that is the duct's main skin. underneath that (and on the other side of the wire) there is a thin clear plasic film that apparently will not hold up to much negative pressure if the foil is breached.