p.s. On much closer examination of the photos, it does
appear possible for some of the PSU's exhaust air
to recycle back into the angled fan that blows onto the HSF.
Then, there is another pair of intake fans in the bottom
panel, which direct cooler air into this angled fan.
I think the solution to this difficulty would be
to add a baffle which prevents the PSU's exhaust
air from recycling back into the case through that
removable plastic fan grill. Then, that angled fan
would be getting its air from those 2 fans in the
bottom panel, and all of the PSU's warmer exhaust air
would then exit the chassis and rise up and away
(because hot air rises).
MRFS