I discovered this idea while building the District-9 case mod. I wanted to direct the cooler air entering the front of the case to the cpu cooler. The 5.25 bay covers were removed to highlight the canister movie prop we made. It dawned on me that a fan duct could be mounted to a 120mm fan by modifying a 120mm round mesh fan grill. In the past, I would mold the fan duct into the front bezel with body filler, but this method is much easier and more versatile.

This method can be combined with 4.5″ flexible tubing to isolate cool airflow. Imagine one end of the tube attached to a 120mm cooling fan in front of your case.
The 4.5″ Flexible tubing can be found at McMaster.com or you can “try” the “Heating & Cooling” department at hardware or home improvement stores like Home Depot or Lowes.

Supplies & Tools:
120mm Modder’s Mesh Round fan grill
4.5″ fan duct
4, #10 x 5/8″ fan screws
120mm cooling fan.
Paint pen or pencil.
Tin snips.
Wire cutter.

120mm Modder’s Mesh Round fan grill

4.5″ fan duct

Using a paint pen to trace the duct onto the round mesh grill.

a small wire cutter and Tin snips used to cut the 4.5″ opening in the 120mm Modder’s Mesh Round fan grill

You’ll need to use the small wire cutter first, to make the initial cut before you can use the Tin Snips to cut the 4.5″ hole.

Using Tin ship to cut the round mesh grill.

The result of you cutting should look like this.

120mm cooling fan. This fan has enclosed corners, you will need longer fan screws if you’re mounting the fan onto something like a cpu cooler.

4, #10 x 5/8″ fan screws

The fan duct is ribbed, so you can trim down the length for your own application with a saw.