NZXT S340 Fan configuration, any recommendations?

[Harsh Kumawat]

I was looking at PC Part Picker (https://pcpartpicker.com/b/TvxYcf) when I saw Jail Breaks (Tech Source) PC build and I didn't understand his fan configuration. If I recall correctly the way he placed his fans the air is being pulled from the rear and the exhaust is the fans on the H100i GTX & the top fan. But there's no dust filter on the rear so wouldn't his PC be affected by dust?

 

[RCFProd]

What a build that is. But yeah, if he pulls in air from the rear that would make my think he would get dust in his PC.