Question for C25 or similar sized cabinets about airflow.

[Guest]

Whip out the calculators.

My space is a C25. That's 62Hx28Wx20D in inches.

Thats 34720 cubic inches, or just over 20 cubic feet.

My fan is a 210cfm and my passive intake is an 8x8 square with a doran light proof from B&H (link: http://www.bhphotovideo.com/bnh/con...104&is=REG&addedTroughType=categoryNavigation)

How big in space are your passive intakes?

Now here's where I start making up stuff a little.

Lets assume that with the ducting static pressure and stuff that I lose 40% of the 210. So thats approximately 126cfm of "suction" applied to 64 square inches of space.

I am not sure how to figure out the rest, but I imagine the point is to reduce the wind speed velocity at the intake, but obviously not let it go so low that there is a lack of air flowing, right?

Since you cant really work with cubes (126 cfm) and squares (64 square inches) I dont know where to go, but Ive always been a fan of ratios..

so thats a 2:1 ratio (almost exactly)

So I want to see where I stand.. quick, add up your stuff and see what your ratio is?

 

[70s_PotHead]

Well I dont do ratios all that well but my cab is 48 cubic feet and I've got a fantec 250 so my air changes in the cab roughly 5 times per minute.

6 inch to fan at top corner of cab


6x12 opening at opposite bottom side of cab, air drawn thro a light trap


12x20 A/C filter intake on outside of light trap


hope that helps..

70s

 

[Tokabowl]

My cab is 1m x 0.5m x 1.6m = 0.8 m3
I have a 4" RVK fan with an airflow of 227m3/h, which, counting 40% loss is about 136m3/h so roughly 2.3 m3/min, which means that, theorectically, the air in the cab changes nearly 3 times every minute.
I have passive intakes that measure 25x9 cm and 20x10 cm.

Im not sure how to calculate the relation between size of intake and airflow, but assuming that your intakes are sufficiently big, with a fan running @ 126cfm, your 20 cubic ft will be renewed about 6 times every minute.

Hope this makes sense

Peace

 

[Guest]

Well I dont do ratios all that well but my cab is 48 cubic feet and I've got a fantec 250 so my air changes in the cab roughly 5 times per minute.

hope that helps..

70s

Thanks.

250cfm = 150 after 40% loss from static pressure

and 6x12 = 150 sq inches.

So you have a 1:1 ratio!

 

[70s_PotHead]

Thanks.

250cfm = 150 after 40% loss from static pressure

and 6x12 = 150 sq inches.

So you have a 1:1 ratio!

So is that good?? I know it works good



70s