Fan+Filter CFM, what do you think about this set up?

My room is 10x10x6.6 (120x120x80 secret jardin)

I have a 10x39 1400CFM phresh filter and a 10in Hyperfan rated at 1065 CFM

Does that seem fine? Is it ideal? If not, what would have been better?


And the 2nd part to the question, what size should my intake fan and filter be?

That is a huge fan for the size of your room. What size lights are you going to be using. As I have the same size fans as you and run 6x600 hps.
And the my room is 3x2.5x1.8 meters

I thought I might have gone a bit overkill. But your room is smaller than mine so what do you mean?

I'll be running 4 1000s. So my watts are higher than yours too.

Ok sorry I don't no why I was looking at it wrong. I only run the 6 lights at the start of flowering and then add 3 more 2or3 weeks in.
I do also like the idea of a over kill. As it is winter here I only use the 2 fans but I have 4 in total. I have 2x10 inch fans drawing the air in and 1x10 and 1x12 inch both with filters drawing the air out. But I never need to use the 4 of them over winter

bryangtho said:

Ok sorry I don't no why I was looking at it wrong. I only run the 6 lights at the start of flowering and then add 3 more 2or3 weeks in.
I do also like the idea of a over kill. As it is winter here I only use the 2 fans but I have 4 in total. I have 2x10 inch fans drawing the air in and 1x10 and 1x12 inch both with filters drawing the air out. But I never need to use the 4 of them over winter

Click to expand...

So your intake fan is about 1000cfm or so and then you have over 2000cfm as your combined exhaust fans?

My room is designed for very hot temp as it can get very hot here. So my intake fans are 1100 cfm each so that's 2200 cfm. And I have 2 outlet fans one of them is 1100cfm and the other is about 1800 cfm. Here's a couple pictures of my set up

Dayummmmmmmmm. I thought i was overkill. So heres another thought...

I know that a carbon filter is supposed to have slightly higher cfm rating than your fan, but what happens when it is SIGNIFICANTLY higher? I'm trying to understand the physics/math behind it. Say a 1065 cfm fan is attached to a 3000 cfm carbon filter...what kind of effect does this have?

I would really prefer to not use passive air. Doing the math, 25% reduction on the 1065 fan due to the carbon filter puts it at 800cfm exhaust. About 20% reduction on the 400cfm puts it at 320 cfm intake. I thought that should be fine but it isnt NEARLY enough. If i keep the fan at 100% (800cfm) the walls of the tent concave so hard so fast that i quickly turn it off because it looks like its literally going to break the tent. I need someone to explain to me the math behind exhaust and intake CFM. A ratio where i would get slight negative pressure to keep everything inside.

Am i just over complicating it in my head? Logically if you have 800cfm exhaust and 800cfm intake then you have 0 negative pressure and no concave. Slightly reduce the intake to something like 600cfm and you'll have your slight negative pressure without too much strain on the tent supports. Is it this simple?

I was using 4x 10inch fans but because I had 2 x1100cfm pushing the air in. And 2x1100 pulling the air out with the carbon filter on them. I was getting air being push out of any crank it could get out of. So that's why I went with a bigger exhaust fan. I think tents makes it a little harder but 20% sounds about right. You could just use a speed fan controller to control one of your fans or both of them. I have a veg room witch is a tent I don't run any carbon filters on it at all. Both the fans are 10inch and it runs prefect. If that was my room I would get 2 big fans the same size and put a speed control on your intake fans