• Here is a link to the full explanation: https://rollitup.org/t/welcome-back-did-you-try-turning-it-off-and-on-again.1104810/

How Does A Fan & Filter Work

Maryjane123

Well-Known Member
How does filter & fan work ?

I have it all setup in grow tent but what I'm confused about is how does it extract the warm air and smell out of tent? and bring in cooler air? as my ducting is outside of tent in my room and the fan & filter is inside grow tent. (they are all attached together)

Can anyone help?

I also have a 18 inch high velocity fan in there but thats blowing the warm air around so was wondering how does the fan& filter work when ducting is outside the grow tent?

So confusing :s
 

gotot

Well-Known Member
ok
1. exhaust lowers the pressure of the air i.e. cooling it
2. a carbonated filter filterates oder through it
3. an intake fan brings new co2 into the room as well as cooling it(assuming the outside pressure is lower than your growroom which it will always be)
 

Maryjane123

Well-Known Member
ok
1. exhaust lowers the pressure of the air i.e. cooling it
2. a carbonated filter filterates oder through it
3. an intake fan brings new co2 into the room as well as cooling it(assuming the outside pressure is lower than your growroom which it will always be)
thanks for reply buddy, thing is tho, I don't understand where the cool air brought into growtent would come? because if the ducting is bringing in the fresh air, where is it released because ducting is outside tent and the extractor fan and carbon filter are attactched together with jubilee clips and also ducting is attached with jubilee clip and is hanging at top of tent...

I put my hand over the filter part and fan but can't feel any cold air or any air at all coming from it, When I put my hand in the ducting a little, I can feel cool air but the ducting is outside of tent to bring in fresh air.

This is confusing me something crazy, just quite understand it yet:shock:

Cheers for all help

MJ123
 

gotot

Well-Known Member
i think what your looking for is a air conditioner... then you duct it into the room... your exhast ducting is where the fresh air exits... i cant really picture what your talking about
 

T.H.Cammo

Well-Known Member
It has to work as part of a whole "ventilation" system. If you just have an exhaust fan (with ducting and a carbon filter hooked up), with no provision for inleting fresh air, then that would be kind of like sucking on a bottle (no freeflow of air). You need to have some kind of opening to allow fresh air to enter in order to create a "draft".

Thermodynamics dictate that hot air rises to the top - so that is where your exhaust port should be. Your "Inlet" port should be near the bottom, allowing cooler, fresh, air into the system. As this fresh air gets "used up" (as the CO2 gets stripped away) it becomes a little lighter and rises a little bit on it's own. Then as the lights heat the air even more, it rises to the top and gets sucked out by your exhaust fan.

That's how it should work! You need two ports, one at the top for exhaust and one at the bottom for intake. Your intake can either be passive or active, but if you're going to have two vent fans use them both as parallel exhaust fans - you get twice the airflow that way!
 

Maryjane123

Well-Known Member
It has to work as part of a whole "ventilation" system. If you just have an exhaust fan (with ducting and a carbon filter hooked up), with no provision for inleting fresh air, then that would be kind of like sucking on a bottle (no freeflow of air). You need to have some kind of opening to allow fresh air to enter in order to create a "draft".

Thermodynamics dictate that hot air rises to the top - so that is where your exhaust port should be. Your "Inlet" port should be near the bottom, allowing cooler, fresh, air into the system. As this fresh air gets "used up" (as the CO2 gets stripped away) it becomes a little lighter and rises a little bit on it's own. Then as the lights heat the air even more, it rises to the top and gets sucked out by your exhaust fan.

That's how it should work! You need two ports, one at the top for exhaust and one at the bottom for intake. Your intake can either be passive or active, but if you're going to have two vent fans use them both as parallel exhaust fans - you get twice the airflow that way!
So I think I have exhaust right, but would my intake be the 18 inch high velocity fan?
 

gotot

Well-Known Member
It has to work as part of a whole "ventilation" system. If you just have an exhaust fan (with ducting and a carbon filter hooked up), with no provision for inleting fresh air, then that would be kind of like sucking on a bottle (no freeflow of air). You need to have some kind of opening to allow fresh air to enter in order to create a "draft".

Thermodynamics dictate that hot air rises to the top - so that is where your exhaust port should be. Your "Inlet" port should be near the bottom, allowing cooler, fresh, air into the system. As this fresh air gets "used up" (as the CO2 gets stripped away) it becomes a little lighter and rises a little bit on it's own. Then as the lights heat the air even more, it rises to the top and gets sucked out by your exhaust fan.

That's how it should work! You need two ports, one at the top for exhaust and one at the bottom for intake. Your intake can either be passive or active, but if you're going to have two vent fans use them both as parallel exhaust fans - you get twice the airflow that way!
that's what i didn't understand, he was calling just circulating air "fresh air"
 
Top