Hello, what filter material do you recommend for a case that is subject to the hair in the air resulting from 3 Bernese Mountain dogs? I build lower end towers with both 80mm and 4.75 fans. the "sponge" type filters last about a day and a half w/o cleaning. And please do not suggest getting rid of the dogs. At least they are not cats.
LOL I dont know anyone who would say get rid of your dogs...if they do they are mean.
Do you have any grills on your fan?
How does this look to you?:
It should fit on your 80mm fan.
Silverstone FF81B 80mm Fan Filter with Grill (Black) $11.99
The grill should help with dust/hair.
However due to your situation a monthly cleaning may be required though, even with the best filters.