COMPUTER AIRFLOW/ CHASSIS FAN DESIGNING DEMYSTIFIED

Had setup a server at home. Did some research on the AIRFLOW in and out of the CHASSIS.

TIPS 

1. BIGGER FAN(120MM with 1200RPM) controls temperature better.
2. BETTER CABINET from GOOD Vendor gives added advantage. You may get inbuilt FAN with CHASSIS.
3. LOOK for LAWS/RULES governing HEAT transfer. Click here for Rules : http://www.techpowerup.com/forums/showthread.php?t=42853
4. BETTER to control the FAN/ POWER connection via MOTHERBOARD. Best to AVOID straight connection to FAN from SMPS. Straight connection makes the FAN NOISY and reduces the LIFE OF FAN.
5. FIND the direction of AIR FLOW at the CPU FAN(4pin) which is controlled by Motherboard.
6. FIND the direction of AIR FLOW at the GPU/VGA/Graphics Card at PCI/PCIe/PCI2.0 slots. This card may contain INBUILT FAN. IF so check the AIR FLOW direction.

Cooler Master Economy Pack 120MM FAN http://www.coolermaster.com/product/Detail/cooling/case-fan/silent-fan-120-si2.html

Finding AIR FLOW DIRECTION http://www.youtube.com/watch?v=wlgfAO2Jtls

Also to find AIR FLOW direction, place a piece of paper near the FAN. If it sucks in then AIR IN and expels then AIR OUT.

Does 3PIN FAN connector fits into 4 PIN MOTHERBOARD??? YES. Make sure to connect the GND to BLACK WIRE FROM FAN. 4th PIN is for PMW(Pulse Width Modulation), which is used to control RPM on the FLY from UEFI BIOS/ SOFTWARE from OS. JUST 3 PIN FAN also works by leaving PWM PIN. More Info : http://hardforum.com/showthread.php?t=1692017

MY CHASSIS AIRFLOW DESIGN (Best I can GET FROM TRIAL and ERROR Method)

CoolerMaster CMP250 http://www.coolermaster.in/product.php?product_id=6761&category_id=19

4* 120 MM CoolerMaster 1200RPM 3pin FAN http://www.coolermaster.com/product/Detail/cooling/case-fan/silent-fan-120-si2.html

AIR IN - ONE FRONT BOTTOM, TWO SIDE PANEL

AIR OUT - REAR TOP, SMPS TOP FAN

CPU FAN - SUCKS AIR INTO HEAT SINK

MY COMPUTER CHASIS AIR FLOW

UEFI BIOS REPORTS TEMPERATURE AND FAN SPEED

CONCLUSION : ONLY THIS SETUP GAVE BEST RESULTS (ie TEMPERATURE DIFFERENCE OF Approx 5 deg centigrade lesser if compared with OTHER SETUPs).