I put a 250mm fan in my beautiful Lian Li case. It was an attempt to try and bring down the noise level, increase cooling, and make a single point of entry instead of having all sorts of fans all over the place. This was an elegant solution (to me). In the end, I didn't even need any fans on my Northbridge or CPU, just heat spreaders, since the huge fan blew so much air through the case.
My particular case has hole all over the front, bottom and back, so your milage may vary. I used those as exit holes, and the 250mm was input. that way I could control a dust filter in 1 place.
This instructable is meant to be more of an overview. If enough people are interested, I'll get into how to make it a little deeper. I recognize this looks like ass, and given more time, I would have made a much nicer one. But this is the best I could do in my allotted time.
Another reason i did this was because I was fed up trying to use different, ineffective filter media. Pantyhose didn't work, nor did speaker grille material, or household pleated paper filters. All either restricted airflow to where no air was getting through, or just didn't work. Industrial fiberglass filters finally worked well, and didn't restrict airflow too much.
Step 1: Parts List
I have a 250mm fan already installed. I had to kind of jury-rig the fan so the metal guard was on the inside of the panel. This gave more room for the filter media.
1. The fan came from here: Xoxide.com dd
2. Angle aluminum to make the frame.
3. Some flat stock right angle corners.
4. Screws & nuts
5. Piano hinge
6. A nice drawer pull
7. Some Velcro I had lying around
8. Wire or other thin media to make the grid to hold the filter media in the frame.
All this came from Lowe's.
Step 2: Frame Construction
Simply assemble the frame with the right angle aluminum & the flat corners. Cut the angle aluminum to frame the circle of the fan. Drill holes to allow the bolts to connect everything together.
I drilled holes along the edge and strung the and just wove some thin wire in & out. This basically just keeps the filter material from falling out.
Step 3: Get It Together
Put it all together. Attach the piano hinge to the bottom of the frame with 2-3 screws. Attach the assembly to the computer side panel with 2-3 screws. I used the Velcro at the top to just keep it closed.
Step 4: Final Thoughts
I bought filter media from McMaster Carr. It's a nice roll of material. PN PR10T10-15. Alias 10" x 15' x 1" tack polyester made by Aero-flo Industries.