corsair 750D case cooling fans question

richbambam

Honorable
Nov 7, 2013
1
0
10,510
1st of all hi everyone

my question is I just built a rig,my case choice was a corsair 750D this came pre-installed with 3 fans the rear was 140mm exhaust fan & the 2 140mm front fans are intake fans,I have now purchased the corsair 100i rad liquid cooler & this will be at the top of the case & the fans set to intake to keep the rad cool,I have also ordered 2 120mm fans to go at the bottom of the case should I set these to intake or exhaust seeing as I only have one exhaust at the rear & thinking if I set them to intake they will be blowing the warm air back into my hd7990 gfx card which have 3 fans pointing down on the card,Im just to get the best help on how to set up my fans
 

yacard

Honorable
Sep 3, 2013
12
0
10,510


When you are setting air direction or flow you must consider:
* As the air heats up will tend to move up
* Positive pressure (intake cfm > exhaust cfm) to reduce the amount of dust coming into the case.

I would set all fans in the bottom/front as intake (cold air coming in front the bottom), the H100i in pull config (for easy maintenance) as exhaust(moving hot air out of the case), and I would do simple math to calculate best config for the rear one to obtain Positive pressure. (sum of all intake > sum all exhaust).