desired CFM for 4'X4'X7' w/ 400 watt?

[GaGrown]

the fabric relief damper is something you use to release negative pressure.At the same time it can be used in conjunction with a fan to pull fresh air in and refresh the depleted air with outside c02.It needs to be positioned low in the room,and you fan up high.Not too close together,though! It's called passive airflow!

Ga Grown

[Jdog7000]

I'm planning on using a hepafilter over a hole somewhere.
Atach a duct to it.
And run it to the floor.
That way the negitive pressure will suck the fresh air in from OUtside or another room.
We'll see how the place is built.

[GaGrown]

Jdog your right on the money!

Holla!
Ga Grown

[GaGrown]

lemme add this.The hepa filter will restrict the airflow some what.It takes alot of air to build negative pressure.so to make your passive air work in order to recieve some of that precious c02 from outside air,your gonna have to use a filter that is less restrictive! Hows that for grammar?

Holla!
Ga Grown