I'm almost done with my DAN A4 v3 build. Overall the case has excellent build quality, but the airflow remains unsatisfactory. v4 should fix some of these issues, but the case could have 10-20C better thermals with some changes.
Only slim fans will fit like Noctua NF-A9x14 or Akasa Slimfan, or small 40mm fans like NF-A4x20. The problem is, the slim fans don't have enough static pressure to pull air through either the case or bottom ventholes without making intolerable high-pitch noise. You can try turning on a fan and moving it either in pull or push next to the mesh, and see the change in noise. Small fans like NF-A4x20 on the other hand pull less than a fifth of the air volume compared to NF-A9x14 (9.4h vs. 50.5 m3/h), so they don't really do much.
Right now fixing the airflow is really difficult, since the only fans that fit won't have the static pressure to deal with this mesh, even if they'd pull nearly as much air as bigger 120mm fans. The best I can do without cutting the case is adding NF-A12x25 to the backside and Akasa Slimfan in front of the motherboard, both bolted and pushing through the mesh. Custom side/top panels could give less resistance for the fans. Or if the case was just a tiny bit bigger, it could fit 120mm fans in bottom and top to get a good airflow through without noise.
I'm considering heavily modding the case to get the airflow fixed. But it's probably just easier to see how v4 will turn out, or switch to a competing case that fits 120mm, like Ghost S1.
Only slim fans will fit like Noctua NF-A9x14 or Akasa Slimfan, or small 40mm fans like NF-A4x20. The problem is, the slim fans don't have enough static pressure to pull air through either the case or bottom ventholes without making intolerable high-pitch noise. You can try turning on a fan and moving it either in pull or push next to the mesh, and see the change in noise. Small fans like NF-A4x20 on the other hand pull less than a fifth of the air volume compared to NF-A9x14 (9.4h vs. 50.5 m3/h), so they don't really do much.
Right now fixing the airflow is really difficult, since the only fans that fit won't have the static pressure to deal with this mesh, even if they'd pull nearly as much air as bigger 120mm fans. The best I can do without cutting the case is adding NF-A12x25 to the backside and Akasa Slimfan in front of the motherboard, both bolted and pushing through the mesh. Custom side/top panels could give less resistance for the fans. Or if the case was just a tiny bit bigger, it could fit 120mm fans in bottom and top to get a good airflow through without noise.
I'm considering heavily modding the case to get the airflow fixed. But it's probably just easier to see how v4 will turn out, or switch to a competing case that fits 120mm, like Ghost S1.