Question on grow closet

[Joebob69]

Hi I have a 2x6x8 closet..using dwc with led light....by my calculations I'll need about a 200cfm exhaust? My main question is that in a little closet like this, can I get away without using a forced air intake and just let my exhaust pull in fresh air through a 4in hole towards floor? Or do I need to force air into my closet? Any advice would be great! Thanks!

 

[Tead]

No need for the 2nd fan. I feed cool air (a/c) into one of the lower holes and let it vent naturally out the top. I believe the fans are more effective at pulling air rather than pushing it, so you might want to use your fan pulling hot air from one of the top holes..... hot air rises after all.

 

[Weaselcracker]

My fan, near the top of room, kicks on when the thermostat gets to about 80, and vents hot air out, creating a vacuum. This sucks cool air from outside in through the bottom vent, which has a hinged door. Gravity closes the door when the fan turns off and the vacuum effect stops. My outside air is always pretty cool, so this system works great- cools the room while bringing in fresh air often. During lights off the vent fan doesn't come on often because the room doesn't heat up much. Movement fans stay on though.

 

[Joebob69]

No need for the 2nd fan. I feed cool air (a/c) into one of the lower holes and let it vent naturally out the top. I believe the fans are more effective at pulling air rather than pushing it, so you might want to use your fan pulling hot air from one of the top holes..... hot air rises after all.

what I figured, thanks! Sounds like my set up is similar to yours

 

[Joebob69]

My fan, near the top of room, kicks on when the thermostat gets to about 80, and vents hot air out, creating a vacuum. This sucks cool air from outside in through the bottom vent, which has a hinged door. Gravity closes the door when the fan turns off and the vacuum effect stops. My outside air is always pretty cool, so this system works great- cools the room while bringing in fresh air often. During lights off the vent fan doesn't come on often because the room doesn't heat up much. Movement fans stay on though.

Thanks for the info!

 

[Joebob69]

No need for the 2nd fan. I feed cool air (a/c) into one of the lower holes and let it vent naturally out the top. I believe the fans are more effective at pulling air rather than pushing it, so you might want to use your fan pulling hot air from one of the top holes..... hot air rises after all.

will this method work with soil too? Since dwc uses an air pump...I didn't know if they would have enough oxygen in soil..

 

[iwltfum]

will this method work with soil too? Since dwc uses an air pump...I didn't know if they would have enough oxygen in soil..

The two should not be related

 

[Joebob69]

The two should not be related

I'm just saying that I'm thinking about growing in soil in my closet rather than dwc..

 

[iwltfum]

will this method work with soil too? Since dwc uses an air pump...I didn't know if they would have enough oxygen in soil..

Which method?

I think you'll find that growing in soil gives the roots plenty of oxygen. DWC delivers much more, but more oxygen is necessary as the roots are sitting in water the whole time. If you have a poor draining soil, you plants will develop problems in the same way as if your plants were sitting in a deep water culture system without proper oxygen input. But with a soil that drains properly, the soil will hold both air and water even if the plant was just watered.

 

[Joebob69]

Which method?

I think you'll find that growing in soil gives the roots plenty of oxygen. DWC delivers much more, but more oxygen is necessary as the roots are sitting in water the whole time. If you have a poor draining soil, you plants will develop problems in the same way as if your plants were sitting in a deep water culture system without proper oxygen input. But with a soil that drains properly, the soil will hold both air and water even if the plant was just watered.

Thanks.. I'm trying to ask if I need to force air into my closet growing in soil, or will letting my exhaust pull in fresh air through a duct towards the floor be sufficient? I know it would be fine for dwc, but was wondering if it was ok for soil too...

 

[Tead]

You seem to be suffering from a minor misunderstanding....
The exhaust fan system for your grow tent has no real impact on your grow style. More air flow will not make any difference if your using hydro or soil. You want the same good air flow for both. The venting of the tent doesn't "inject" air into the soil.
In soil, we create a thin mix that provides for lots of drainage. This allows the soil to dry between waterings thus getting air into the soil and roots. For example, I might use a potting mix straight out of the bag for tomatoes or other garden veggies, but for MJ, I add about 30%-40% perlite to thin it and provide drainage.
There are some growers that use air pumps and really wet soil.... but that's something completely different.

 

[iwltfum]

You seem to be suffering from a minor misunderstanding....
The exhaust fan system for your grow tent has no real impact on your grow style. More air flow will not make any difference if your using hydro or soil. You want the same good air flow for both. The venting of the tent doesn't "inject" air into the soil.
In soil, we create a thin mix that provides for lots of drainage. This allows the soil to dry between waterings thus getting air into the soil and roots. For example, I might use a potting mix straight out of the bag for tomatoes or other garden veggies, but for MJ, I add about 30%-40% perlite to thin it and provide drainage.
There are some growers that use air pumps and really wet soil.... but that's something completely different.

that answer you question joebob69? Basically, you will want good air flow whichever method you choose. Generally with inline ventilation, it is much more efficient to be pulling rather than pushing. But a fan pulling air into the room should be secondary to a fan pulling air out of the room only if the fan pulling out does not work well enough because the air flow should come passively if you have a strong enough fan.

 

[Joebob69]

that answer you question joebob69? Basically, you will want good air flow whichever method you choose. Generally with inline ventilation, it is much more efficient to be pulling rather than pushing. But a fan pulling air into the room should be secondary to a fan pulling air out of the room only if the fan pulling out does not work well enough because the air flow should come passively if you have a strong enough fan.

Yes it did, thanks!