Having trouble getting this because of the Great Firewall. Their should have been room for 25mm thick fans at the bottom but the design of the case prevents it a bit. I think the big concern is the way the shell closes over the inner chassis, some of the tabs used to screw it in may scrape against if if you aren't careful. At the bottom I guess you have room for about a 25mm x 170mm x 40mm area of space. If you were to cut the chassis yourself you could open that to 25 x 170 x 60 i think.