GreenAndTastey
Active Member
First time poster, setting up my first grow cabinet in a while (over 5 years)
I'm only looking to grow 1 plant in a 1.6 ft x 1.6 ft x 5 ft custom built cabinet. So total volume 12.8 cubic feet
Tomorrow I'm building the cabinet in a walk in cupboard that has temps of around 22 degrees C and RH around 50% before the cabinet is installed
The smallest exhaust fan I could source was rated for 47.08 CFM, same story for the carbon filter (rated from 0 - 70 CFM) (figures are before lights and ducting of course)
Naturally because it's a retro fit cabinet I'll be needing to run at a negative pressure, and I'm going to be using passive intake by using a crown to create holes in the floor of the cabinet which will be able to pull fresh air from a Lung Chamber underneath the cabinet.
Because I'm in such a small space I'll be fitting my full spectrum LED's (total "output" 300W, pull from the wall 75-100W) to a 1ft x 1ft board suspended from the ceiling of the room on wire rope so that heights can be easily adjusted, giving me about 0.25 ft of space on each side of the board where air can be pulled through
I read somewhere that because I don't have a clear path between the intake and the exhaust having a stronger fan than the space would require with a clear path from intake to exhaust.
I've also read that passive intake should be about 2-4 times larger than the exhaust, am I right in thinking that I should be having a larger passive intake than this because my exhaust fan is 4 times larger than the space needs?
I've attached an image to the post of a rough paint 3D sketch of the plan. Any tips or advice on what I should do about having a fan so much stronger than necessary would be appreciated. Right now installing a limiter would push the budget over what I set myself but if having such a strong fan is really that much of an issue I'll have no option
Thanks in advanced
really wanna get this right because supply in my city has dried up 
I'm only looking to grow 1 plant in a 1.6 ft x 1.6 ft x 5 ft custom built cabinet. So total volume 12.8 cubic feet
Tomorrow I'm building the cabinet in a walk in cupboard that has temps of around 22 degrees C and RH around 50% before the cabinet is installed
The smallest exhaust fan I could source was rated for 47.08 CFM, same story for the carbon filter (rated from 0 - 70 CFM) (figures are before lights and ducting of course)
Naturally because it's a retro fit cabinet I'll be needing to run at a negative pressure, and I'm going to be using passive intake by using a crown to create holes in the floor of the cabinet which will be able to pull fresh air from a Lung Chamber underneath the cabinet.
Because I'm in such a small space I'll be fitting my full spectrum LED's (total "output" 300W, pull from the wall 75-100W) to a 1ft x 1ft board suspended from the ceiling of the room on wire rope so that heights can be easily adjusted, giving me about 0.25 ft of space on each side of the board where air can be pulled through
I read somewhere that because I don't have a clear path between the intake and the exhaust having a stronger fan than the space would require with a clear path from intake to exhaust.
I've also read that passive intake should be about 2-4 times larger than the exhaust, am I right in thinking that I should be having a larger passive intake than this because my exhaust fan is 4 times larger than the space needs?
I've attached an image to the post of a rough paint 3D sketch of the plan. Any tips or advice on what I should do about having a fan so much stronger than necessary would be appreciated. Right now installing a limiter would push the budget over what I set myself but if having such a strong fan is really that much of an issue I'll have no option
Thanks in advanced
really wanna get this right because supply in my city has dried up 
