How to Power Multiple 80 mm Cooling Fans
- 1). Power down the computer and attach the antistatic wrist strap to one hand and to the case. Disconnect the power supply cord from the wall outlet or from the back of the computer and remove the case cover.
- 2). Mount fans in available mounting locations using the mounting hardware that was included with the fans, making sure to provide a stable airflow in one direction across the interior of the case, typically exhausting hot air out the rear of the case and pulling in cool air from the front of the case. Make sure the fans do not touch other components or cables inside the case.
- 3). Connect the first fan to the power lead on the motherboard marked "Case Fan 1" and the second fan to the power lead on the motherboard marked "Case Fan 2."
- 4). Connect 4-pin to 3-pin Molex power adapters to available 4-pin power leads and connect these to additional fans. A power splitter may be needed where a power supply has few extra leads or they are all in use powering other components.
- 5). Connect a power splitter for 4-pin Molex connectors to one of the 4-pin Molex power leads and attach 4-pin to 3-pin Molex power adapters to each leg of the splitter. Attach these power leads to additional fans.
- 6). Tie power leads and other cables into loose bundles using nylon cable ties to increase air flow within the case. Avoid damaging the conductors by leaving some slack in the cable ties. Snip off excess cable tie material after the cable ties are in place.
Source...