Grow closet questions

[Imaskypilot]

A newbie here. I’m building a 95 sq ft grow closet. I have a six inch inline fan (240 cfm) & filter, so I assume the exhaust will be six inch? I’ve heard that the inlet has to be larger than the exhaust. I also have to get a light proof inlet vent. What is the rule of thumb on inlet vs exhaust? Many Thanx!

 

[Old Salt]

Passive intake vents should have at least double the area of the exhaust. Your exhaust is 28.27 sq in, so your intake(s) should total no less than 56-1/2 sq in. That's a diameter of 8.5", a register 4" X 14", or a 6" X 10" grate.

 

[TurboBucket]

Holy moly a 95sq ft closet.
As noted passive intakes need to be double the size of the exhaust.
A 240cfm fan will be lucky to run 180cfm with a filter on it.

 

[noobgrow1]

I know you didn't ask but I am two grows deep now, let me share one lesson I thought was kinda overkill. Follow the intake suggestions but also do yourself a big favor and make some square inlets that you can swap cheap furnace filters into.

Total months growing estimate 9 months (ish) I did not see any need to filter my inlets only to see sooo much dust build up on my fan blades, they need to be fairly clean to a. save electricity & b. just move more air efficiently and quietly.

Granted I have pets but the grow room mostly has door closed and of course the tent is enclosed. I can't believe how much crap builds on the fans. I work with anything tech hardware related as such see tons of fans & lots of crap build up but my tent fans collect so much more. I am pretty sure that's why they designed server fans to really spin fast at startup. They sound like jet engines small ones! But loud that allows they to shed a lot of debris, which blows all over inside the cabinets but most gets blown out the back.

Can't do that w grow room fans, I am a but lazy part from pain but part lazy w a dash of not liking wasting time on useless crap like cleaning fans. Filters on my inlets next grow, along with my first journal I hope!

Anyway welcome to our corner of the weed web! People here so welcoming and helpful.

 

[Imaskypilot]

Passive intake vents should have at least double the area of the exhaust. Your exhaust is 28.27 sq in, so your intake(s) should total no less than 56-1/2 sq in. That's a diameter of 8.5", a register 4" X 14", or a 6" X 10" grate.

Many Thanx Old Salt !!!

 

[Imaskypilot]

Holy moly a 95sq ft closet.
As noted passive intakes need to be double the size of the exhaust.
A 240cfm fan will be lucky to run 180cfm with a filter on it.

I didn’t know the drop would be that much with the carbon filter! But hey, it’s still changing out twice the volume every minute. Do you see a problem? Many Thanx TurboBucket!

 

[Imaskypilot]

I know you didn't ask but I am two grows deep now, let me share one lesson I thought was kinda overkill. Follow the intake suggestions but also do yourself a big favor and make some square inlets that you can swap cheap furnace filters into.

Total months growing estimate 9 months (ish) I did not see any need to filter my inlets only to see sooo much dust build up on my fan blades, they need to be fairly clean to a. save electricity & b. just move more air efficiently and quietly.

Granted I have pets but the grow room mostly has door closed and of course the tent is enclosed. I can't believe how much crap builds on the fans. I work with anything tech hardware related as such see tons of fans & lots of crap build up but my tent fans collect so much more. I am pretty sure that's why they designed server fans to really spin fast at startup. They sound like jet engines small ones! But loud that allows they to shed a lot of debris, which blows all over inside the cabinets but most gets blown out the back.

Can't do that w grow room fans, I am a but lazy part from pain but part lazy w a dash of not liking wasting time on useless crap like cleaning fans. Filters on my inlets next grow, along with my first journal I hope!

Anyway welcome to our corner of the weed web! People here so welcoming and helpful.

Many Thanx Noobgrow1 !!!
All good info!

 

[TurboBucket]

That may not be enough to cool the space down depending on the heat load and incoming air temps.

Folks have problems with 6 in fans in 16sq ft tents if the conditions are poor enough.

 

[Imaskypilot]

Passive intake vents should have at least double the area of the exhaust. Your exhaust is 28.27 sq in, so your intake(s) should total no less than 56-1/2 sq in. That's a diameter of 8.5", a register 4" X 14", or a 6" X 10" grate.

Old Salt - I’ve heard that you should have negative pressure in the box. Can you have negative pressure when the exhaust hole is smaller than the intake hole? Thanx!

 

[Old Salt]

Yes, it depends on the airflow.

The negative pressure is to control the smell. You don't need much. In my opinion if the sides of your tent are sucked in, you need to open the intakes.

 

[Imaskypilot]

Yes, it depends on the airflow.

The negative pressure is to control the smell. You don't need much. In my opinion if the sides of your tent are sucked in, you need to open the intakes.

Thanx!

 

[Imaskypilot]

Yes, it depends on the airflow.

The negative pressure is to control the smell. You don't need much. In my opinion if the sides of your tent are sucked in, you need to open the intakes.

I see notes after your response about journals completed and journals in progress, what’s all that about? Thanx

 

[Old Salt]

I see notes after your response about journals completed and journals in progress, what’s all that about? Thanx

That's my signature block. We can put anything we want into out signature blocks. What you see are my choices. They are titles or links to content I generated, or that I think other members may find useful.

You can access your signature block by clicking on your name in the black menu at the top of the screen, and clicking 'Signature.' Type what you want to appear in your signature block. To add the links, go to the page you want, and copy the URL from your browser. Go back to your signature block, and highlight the text you want to associate with the link. Click on the chain symbol (ninth from the left) and drop the URL into the box provided. Click 'Insert,' and you're done with that one and can move on to the next.

Edit: Follow the link in my signature to the Mars Hydro contest if you want a chance to win a free grow light.