Is it ok to just have fresh air intake and no exhuast???(rep+)
- Thread starter lifesgood
- Start date
What that's gonna do is create positive pressure in the cab, and not really cool things off all that well. If you have positive pressure that means the air from inside will be constantly seeping out, if you're trying to control odours that's a problem.
mrdrywall
Active Member
the way i understand it you need exhaust not only too take the bad air out but when you attach it to a fiter the smell goes also ive only been growin a yr. and i started with a charcoal filter attached to a centrifigul fan also attached to my light so it cools the light takes bad air out and the smell works great TEN MIN AFTER IT KICKS ON YOU CANT SMELL NOTHIN IN THERE EVEN IN FULL FLOWER sorry hit caps lock wouldnt trade it for nothin
lifesgood
Active Member
Hmm makes sense and thats the whole point of the fresh air intake is to cool things off but i guess without taking the bad air out its not really acting that way right now.....
so i go the intake on the on bottom and i should attach an exhaust on the other side on the ceiling as hot air rises???
Nice yea i exhuasted in the past using aircons but im trying to be a bit more power smart and try using fresh air and fans and i guess an exhaust now to maintain temps...
My only concern with exhaust is , arnt u then also exhausting co2 inriched air???
lifesgood
Active Member
The room is now sealed and there is no passive exhaust. I dropped a light and introduced an aircon that exhuasts out of the room and up a chimney.
Another thing is that my aircon and intake are only on when lights are on, should they be on 24/7???
Due to the way the aircon operates( from time to time sucks hot air out of the room ) would it be wise to install co2? or would that be a waste as the aircon would suck the enriched air out???
Totallly makes sense..... I havnt yet unistalled the intake fan as i want to see how the intake and aircon will work together..... but normally should there be more air exhausting out of the room or more air intaking into that room??
Another thing is that my aircon and intake are only on when lights are on, should they be on 24/7???
keepinabeat
Well-Known Member
more air out and ur heat and humidity will stay low
Waggs
Active Member
Totally agree with this. If u gotta go passive go with it on the intake side.
lifesgood
Active Member
My filter is currently scrubing , shoudl i exhaust that air out as well since i have the option to do so???
for sure, my only concern is that the intake duct is only 6" large and i dont think it could refresh 2 rooms with out the help of an intake fan ... am i wrong???
THe intake should be at the bottom of the room and the eaxhuast on the other side at the top,, correct ??? then there should be about the same amout of air intaking as its exhausting???
seasmoke
Active Member
Yes the exhaust should be up high and the fan should be mounted here. The intake should be located opposite the exhaust. Most people keep it low, but I didn't. I have mine 3/4 the the hieght of the room. Cold air and co2 sink. So when I draw passive air in, I want it to sink down over my plants cooling and supplying them with co2( remember, outside air is FULL of co2). The hot air automaticly rises and causes a natural draft.
Doing it this way constantly gives them co2, so there is no need for a system.(co2 will only work well if the temps are quite high. I like my temps 75*).
Either way, its always best to exhaust air out than pump air in. My buddy blows air in his room with no exhaust and his dehumidifier is always working(generating heat) and his room gets to hot. You need to rid the room of used air and moisture.
Doing it this way constantly gives them co2, so there is no need for a system.(co2 will only work well if the temps are quite high. I like my temps 75*).
Either way, its always best to exhaust air out than pump air in. My buddy blows air in his room with no exhaust and his dehumidifier is always working(generating heat) and his room gets to hot. You need to rid the room of used air and moisture.
JeffersonBud
Active Member
You don't need an intake or exhaust per say. Its called a micro climate. As long as you have fresh CO2, you don't need it. The intake and exhaust are not only to regulate heat (if it's a problem) but to exchange the co2 so your plants don't suffocate.
tilemaster
Well-Known Member
seasmoke is right on the button. people listen up!! Heres is a small simple lesson in cooling a grow OP. Fresh Air is all of our Goals!
The best exhaust system whether u cool ur hoods or not, is a passive intake and active exhaust. This method can be used with or without Co2. (i know nothing of Co2). I imagine to incorporate co2 you would want timers, or atmospheric controlers with settings for your exhaust fan.
How this works is similiar to a high powered batheroom fan. the bathroom fans are generally ducted thru the roof to the outside world. It is very easy to intall roof vents, and humid air should be definitly removed from attic spaces if living in colder climates....
When the cieling fan turns on it removes stale, hot , smelly air, from the cieling area. As the air is removed it creates pressure in the room, and starts drawing air from anywhere it can. This is called passive intake. If you dont give it a place to suck its passive air, itll suck from door or casing cracks, anywhere it can pull air. If you give it a straw to suck from it'll suck from that spot. So if you can punch a hole into another adjacent room , or a crawl space (a cool air sorce), you use that for your intake. When the room is sealed, and the exhaust fan at top of room in running, nice cool air will flood in from the intake. If you open your grow room door to see this effect, your exhaust fan will start sucking air from the door you just opened instead of your intake. Make sense?
So instead of a bathroom fan i use a 6'' inline 400cfm fan running 24/7 in my budd room at cieling height ducted to a carbon filter, going right out the roof vent. i have a 6'' hole cut in my subfloor leading under the house. i shoved 6'' flex duct to the intake hole, and ran it to the cieiling. As seasmoke mentioned , my intake will then let cool air sink down , also conviently mixing with the hottest room air at the top. Which is also where i mount a couple osillating fans. Up high...
Ive notice alot of guys running bigger exhaust fans. i just wanted to finally say im able to cool about 10 lamps with that 6'' exhaust and my intake running 24/7 . but thats allso due to climate, cooling the hoods, and the sq footage of the room the grow is located in correlates to the heat. hope this helps any1 tackling vent issues
The best exhaust system whether u cool ur hoods or not, is a passive intake and active exhaust. This method can be used with or without Co2. (i know nothing of Co2). I imagine to incorporate co2 you would want timers, or atmospheric controlers with settings for your exhaust fan.
How this works is similiar to a high powered batheroom fan. the bathroom fans are generally ducted thru the roof to the outside world. It is very easy to intall roof vents, and humid air should be definitly removed from attic spaces if living in colder climates....
When the cieling fan turns on it removes stale, hot , smelly air, from the cieling area. As the air is removed it creates pressure in the room, and starts drawing air from anywhere it can. This is called passive intake. If you dont give it a place to suck its passive air, itll suck from door or casing cracks, anywhere it can pull air. If you give it a straw to suck from it'll suck from that spot. So if you can punch a hole into another adjacent room , or a crawl space (a cool air sorce), you use that for your intake. When the room is sealed, and the exhaust fan at top of room in running, nice cool air will flood in from the intake. If you open your grow room door to see this effect, your exhaust fan will start sucking air from the door you just opened instead of your intake. Make sense?
So instead of a bathroom fan i use a 6'' inline 400cfm fan running 24/7 in my budd room at cieling height ducted to a carbon filter, going right out the roof vent. i have a 6'' hole cut in my subfloor leading under the house. i shoved 6'' flex duct to the intake hole, and ran it to the cieiling. As seasmoke mentioned , my intake will then let cool air sink down , also conviently mixing with the hottest room air at the top. Which is also where i mount a couple osillating fans. Up high...
Ive notice alot of guys running bigger exhaust fans. i just wanted to finally say im able to cool about 10 lamps with that 6'' exhaust and my intake running 24/7 . but thats allso due to climate, cooling the hoods, and the sq footage of the room the grow is located in correlates to the heat. hope this helps any1 tackling vent issues
jiesstonedalot
Active Member
http://cgi.ebay.co.uk/IN-LINE-SHOWER-EXTRACTOR-FAN-LOFT-KIT-TIMER-125mm-5_W0QQitemZ170422786172QQcmdZViewItemQQptZUK_Home_Garden_Hearing_Cooling_Air?hash=item27adfd587c
i got this fan , but as it has a built in timer , that dont stay on for more than 10 mins , does any one know if i can bypass the timer on it so that it stays on , at the moment i put it on , then after bout 10 mins , it cucts off , so i have to disconect the live wire then put it back in before fan goes back on again , cheers jie
i got this fan , but as it has a built in timer , that dont stay on for more than 10 mins , does any one know if i can bypass the timer on it so that it stays on , at the moment i put it on , then after bout 10 mins , it cucts off , so i have to disconect the live wire then put it back in before fan goes back on again , cheers jie
lifesgood
Active Member
Monitored the rooms last night, both temps and humidity dropped. 
Now there floating at 85 F and 35%.
INtake is still controlled by a fan but only because it has to supply air to 2 meduim sized rooms from a 6" duct... Still not sure how much air is blown in as to how much air is exhuasted as the aircons turn on and exhuast air when a certain temp is reached but something seems to be working....
I do also have a filter scrubbing inbetween the 2 rooms that i change to an exhuast.. shoiuld i?
I didnt know outside air was FULL of co2, How is that possible and what are we taking about 1000ppm+???
JUst wanna ask with these passive intake systems say your drawing air from outisde...... would the stinky air from in the room escape out the intake when the rooms exhaust fans are off??? becuase then there is no sucking or would that passive intake still somehow act as an intake>?>??
Now there floating at 85 F and 35%. INtake is still controlled by a fan but only because it has to supply air to 2 meduim sized rooms from a 6" duct... Still not sure how much air is blown in as to how much air is exhuasted as the aircons turn on and exhuast air when a certain temp is reached but something seems to be working....
I do also have a filter scrubbing inbetween the 2 rooms that i change to an exhuast.. shoiuld i?
Intresting stuff.... 1 of the rooms the intake is 3/4 and dropping over the plants where as the other room the intake is on the ground , i dont think its that big of a deal but yes i agree it would be better if that fresh air was sinking over the plants.....
I didnt know outside air was FULL of co2, How is that possible and what are we taking about 1000ppm+???
Makes complete sense, thanks for putting it that way!!!!!!!!!!!!!
JUst wanna ask with these passive intake systems say your drawing air from outisde...... would the stinky air from in the room escape out the intake when the rooms exhaust fans are off??? becuase then there is no sucking or would that passive intake still somehow act as an intake>?>??
tilemaster
Well-Known Member
it would still create an ongoing draft coming from the intake straw so to speak. Not nearly as strong as a draft when the bud room door is closed and the exhaust is running. if you have ur carbon scrubbber hooked to the cieling mounting inline exhausting on a thermostat or timer, ive noticed from down time you can catch smell . so i run mine 24/7, to make sure the air is being scrubbed. Thats obviously a problem with co2 users. also passive intake thats direct to the outside air can be problematic in the winter time if your in a cold environment. if your sucking frezzing cold air youll sweat all over the place in the room from condensation. That should be duly noted in the same regard as venting to a attic in a cold winter area. Dont do it!! Run a line thru the ridge, unless you have plenty of gable venting!. So back to passive intake, i draw cooler air from another source, my crawl space under the home. Its different for every grow site, but passive air is so key. you dont ever need to blow intake with a fan. i started this common mistake by thinking venting my lights was exhausting the room. wrong. exhausting lamps is exhausting just that. stilll got to exhaust the room. better the room then the light itself if your hoods not a ventable make. hope this all makes sense. Hit me up if u gotz ne questions i can answer.
lifesgood
Active Member
Makes loads of sense , thanks good stuff to know about venting....
Just like u i have a crawl space adjasent to the rooms BUTits a crawl space with no concrete floor just the foundation soil the house was placed on making the air quite humid stale and lots of bugs in there...
i chekc the temp and humdity of that crawl space, it was 65F 60% at that time of the year.... so i could use it as place to vent my charcoal filter into orrrr i could try to use it as a passive intake which would bring in that cooler staler more humid air... is it worth a shot....
Does ur crawl space have a concrete floor or is like mine?? and if its like mine any problems with humidity or is that not a factor since the air in the grow rooms is getting exchanged very quickly nopt allowing humidity to rise....
seasmoke
Active Member
tilemaster is dead on with that. Thats the philopshisy(sp) I follow. And to answer your ? about c02 ppm vs the outside and it being FULL of c02? Outside has an endless supply of co2, as long as its being supplied, it doesn't matter how much there isnin an injch. If you have dead air, then it needs to be suppied, and enough to "feed' the plants. Outside air has eveything your plants need, including co2 in abundance.....a carbon filter on a exhaust vent will take care of smell if done right.