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Only exhaust necessary?

onwi

New Member
hey guys,


i was just wondering, i've been doing a lot of research about enhancing the efficiency of my growroom, and there always seems to be mention of exhaust and intake fans.

i've already got the materials to build an exhaust box to go over the window in the room, but an intake fan would not really fit into the scheme of neighbouring rooms and stuff.

so my q is whether its absolutely necessary to have a intake fan, or if its just ok to have ur avg oscilating fan and just open the door every once in a while?


haha thanks heaps for any help =D
 

onwi

New Member
Cool. so bascially its the c02 they need. so would the problem be fixed if instead of an intake you put some sort of co2 tank or like that whole vinegar mixture thing?
 

CustomMX6

New Member
Well, first of all, it all depends on how many plants and how big the space is. I grew mine in my walk-in closet and never had an intake or exhaust. But thats cause I could open and close the door often, or hell sometimes I just left it open. But, if it's a small space it would prolly be better to have I/E. If they get there own room, I wouldn't bother with either, just use the window and doors for ventilation. Good luck man
 

Herban Legend

New Member
Just remember, the more the plants can breathe, the better they produce.
Fresh air works better than any nutes or boosters on the market.
The people who grow pot with poor ventilation setups seem to have constant problems and are never seeing the full potential of their plants.
Besides a exhaust is cheap and easy.(A lot cheaper than the lights) So why deprive your ladies with the only thing that is free in a grow(AIR).
Intakes are not always needed but a exhaust fan works wonders.
 

onwi

New Member
:D woo. so i dont necessarily need an intake :)

thanks herbanlegend!
 

Viracocha711

New Member
An exhaust is only as good as the intake! If you only have small cracks for intake of air then regardless of how big your exhaust fan is you are limited to the amount of air that can be drawn into the room by the exhaust pulling air out...You do not need an "intake fan" so to speak, but if you go through the trouble of installing an exhaust fan, at least create a way for the exhaust fan to work to it's fullest by having a place for the intake of air...If not, then why by an exhaust fan?
 

Herban Legend

New Member
I use a static(no fan) intake from a larger room but not everybody has that kind of room. I prefer the negative pressure to to keep odors in the room. Carbon filters work great but some plants like AK47 and skunks puts out really powerful aromas.
 

onwi

New Member
hmmm. trouble is i read that you should keep ur exhaust up high and intake down low or some thing. and the grow room is only connected to one other room and thats filled with carpet. and that makes me worried about mites and dust gettin into the room if i place the intake low. and smell mite be an issue too.

btw herban legend id ont get your "static" fan thing. how do they work?

does it keep the smell in the growroom more?



thanks too to Virachoca:)

thanks for the help =D
 

Viracocha711

New Member
By static I think he means that the rest of his house, or at least the other room has pressure from either a fan or the fan from the house AC/Heat unit...What this does is create "Static Pressure" similar to the forces exerted on the walls of a balloon, but in this case it would be the walls of the room...So, by having a static intake just means he has fresh air flowing into that room by means of static pressure rather than a fan in the growroom...However, to keep static pressure there has to be a fan somewhere, whether it is the fan from the ac/heat unit in a house or one in the room. I would have to assume he has an exhaust port in the grow room somewhere leading outside in order for the static pressure to flow into his growroom.

This is a very good way of keeping the smell out of your house, however, if the source of the "static Pressure" is turned off, then the smell will creep back into the house, and the plants will not be getting their fresh air.
 
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Herban Legend

New Member
Your correct except the other room is just a room with a/c. Static intake just means it has no fan and works off two or more rooms connected together trying to equalize pressure.(in my case a hole in the wall) I exhaust outside the house thru a Can 66 or 100. So my grow areas are negative pressured. I also have a back up power source for my exhaust fan in case of power outage but its only good for about a hour then the whole house stinks within hours. During the winter, I vent my exhaust to another floor to help reduce the heating bill.
Anyways,I have two static intakes. My static intake is about 6 inches off the floor. Basicly its a neatly trimmed out hole thru the wall with a a/c filter over it.
I will say that having a exhaust fan and a intake fan reduces temp better but in alot of cases its also not needed and could cause odor problems. (I hate to say it but I always learned the hard way when I grew just for personal enjoyment.)
In my case, I have a a/c unit used just for the flower room and the air for my veg and clone room is exhausted into the flower room. A static intake is in the veg and clone room.Threreis also a static intake in the flower room. A 150 cfm fan is removing air from the veg and clone to the flower and a 550cfm fan removes air thru the carbon filter. As a back up I also have a CAP ozone generator but ozone usage is new to me and this unit is really powerful.
 

onwi

New Member
ohhhhhhhh i get it. yeah that makes sense.

um sorry herban legend, but AGAIN another question, what do u mean wen you say that having both intakes and exhaust would cause odor problems? i'd expect it to actually cause less since you're continuously drawing air in and den outside and there woudln't be any chance of the smell seeping back thru unless you turn it off. hahahaha thank you so much for clarifying everything


thanks heaps viracocha and herban legend for your help :D


how do u guys NOE these things. if i dind't use this forum i'd have totally zero idea about all this.... so yeah thanks again guys :p
 

Herban Legend

New Member
If the cfm intake fan is equal or greater than the exhaust fan, odor from strong smelling plants can escape if room isn't sealed tightly. Since smell is a big issue with me I prefer as much negative pressure in grow areas as possble. If odor was not a big issue and no co2 supplement is used, a number of people prefer a more equal pressure for the best cooling effects. But people who seem to have constant problems with pests, people prefer a more positive pressure in the room to create a pressure barrier that repels pests from the room. Each one works well in the right rooms.
Hope I didn't make it more confusing.
 

onwi

New Member
haha nono you cleared up most aspects i didnt' understand. i get you now. positive pressure meaning intake fan greater than exhaust and maybe creates a sorta pressure against pests from the outside getting in? :p

hopefully i get that right. not really a mechanic/physics orientated person...ahhaa sorry herban legend. :p

but yeah thansk so much for taking the time to clarify all these stpuid little points

:D
 

Viracocha711

New Member
Your welcome, they were not stupid...I ask ever single question that pops in my head so that I know exactly what someone is trying to say...That was a good question on the odor thingy, it was not clear.
 

onwi

New Member
yeah i dont think i'll get one anymore. too much of an inconvenience reallly. and it dusn't seem as if the benefits really outweigh the costs. :)

thanks for replying akornpatch :D
 
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