On Tue, 11 Jul 2017 21:54:04 -0700, Bob F wrote:

I always try to position the processor fan so that it's output goes
directly towards the case exhaust fan(s). That, and video cards that
also exhaust out of the case make a huge difference in the case temp,
and therefore the CPU and video card temps. I frequently will make
cardboard deflectors or boxes around the heat sources to help the flow
or heat get out ASAP. The other trick I've done with my last few builds
is to install an intake 5" fan at the back of 3 5 1/4" drive slots, with
a foam filter cut and glued into a "W" shape in the drive bays to filter
the air coming in. It keeps the inside of the PC much cleaner, and the
big intake fan can be run slow enough so it is barely audible. If I
start to hear the processor fan speed up in normal usage, it's time to
clean the filter.

Which is why I've gone Joe Slob about the case, removed the side
opposite the MB mounts, to lay the case down sideways. Hot air to an
extent can simply rise out naturally from the case. My latest slob
job, last week, was to take a nibbler and cut through the steel rolls
forming the upper side of the internal (3.5") drive cage, cutting away
the rest of the top plane with steel sheers. The exposed hard drives
are set loosely balanced and unsecured on their sides, although the
front case fan is still placed and blowing on them. Very, much easier
to swap and make new connections. No rear fan at the backplane, as
upper-mounted power supply has both in- an outtake fans. The PS
served absolutely no aerodynamic function until the Cooler Master and
it's large sideway-oriented fan. Purely happenstance that I could
direct that fan from fins directly opposite, through the cooler, and
closely into the intake fan of the PS fan. With as much happenstance
then to be pleasantly surprised, engaging all eight cores under heat
stress, with a thought to put my hand to the back exhaust PS fan and
feel The Heat coming on strong.

There are cases at the other extreme of extreme efficiency. Except
they're not actually cases, but vaguely a tree-limb construct. Open
and exposed mounting for the individual build components. Not really
my thing, hearsay, although I'll hazard something along this ...
https://www.amazon.com/AeroCool-Fram.../dp/B009RRIP86

Once I liked cases, but those days are gone. Now, if I were any more
a slob, I'd put computers together with nails and screws, into
plywood, maybe with some wire from my handy-dandy "safety-wire"
pliers, found in military applications for twisting wire between
securement anchors used on rumbling B52 bombers, C130s, and likely,
I'll hazard, securing down electronic modules within tanks.

Big advantage, obviously, is it's hard to beat for people who can't
seem to keep their hands out of computers, changing, rearranging
parts, or incessantly tweaking them.

Oh, yea. Airfilters. I just stick on the couch crevice tool on to
the vacuum cleaner's detachable hose, along with a small parts brush,
to get at the worst of it. Fans of course would eventually have to
come out to clean them thoroughly. Surrounded by enough audio gear
that looks don't matter no more, stays pretty clean for the most.