Was thinking a lot about having to clean dust out of ventilation systems and didn't wanna buy a filter so I thought up this one. Used this method for both my HID intake with the big Hurricane fan and room ventilation intake with 109 CFM computer fan. The material is dust and dander cut-to-fit type filter material that costs $2-4 at the hardware store. Used a stapler and some Liquid Nails to attach the screen to the wooden frame circles.
