Mxsmanic, , the pearl necklace-wearing, susurrant
festered sore, and keeper of the kitchen cupboard, whimpered:

More and more, as I look at prefabricated cases for PCs, I ask myself:
what prevents someone from building a PC with no case? For example,
why couldn't you, say, build some sort of wooden mounting area into a
wall or a desk, then mount all the components to it, so that you have
something that blends into the furniture and/or something with plenty
of open space to ease maintenance and keep the machine cooler? Why
does everything always have to be in a cramped box? As long as you
respect things like cable lengths, are there other limitations?

Beyond cable lengths, it occurred to me that perhaps rotating parts
like CD and especially disk drives need to rotate in a horizontal
plane in order to have a symmetric load on the bearings. Is this
true? I've seen PCs in the past with disk drives mounted vertically,
and one of them was quite new (although it failed for other reasons
later on--it was pretty cheap). Do disk drives have to be mounted in
only certain orientations?

Another concern might be EMI, but if you had a metal mesh enclosure or
something around the machine that you could close and ground, wouldn't
that stop EMI? Does anyone really have much trouble with EMI, anyway?

Anyway, what I picture is a sort of vast PC with tons of room between
components, almost like a huge rack in the style of old mainframes
into which you could easily stick your arm if you had to replace
something. Current cases are so cramped that one must pay careful
attention not to break anything when removing or adding parts, and the
air circulation never seems to be anywhere close to ideal.

Maybe something that fits under a desktop (literally) would work.
You'd have a hinged door on the desktop, and when you lift it up, you
have your PC components all nicely mounted in a roomy enclosure with
plenty of space to maintain or upgrade them, and powerful silent fans
to keep the whole thing comfortably cool. It would be the opposite of
a laptop: instead of trying to squeeze everything into the smallest
possible space, you'd be spreading it out into a very large and
accessible place that could potentially give you years of easy and
trouble-free use--and could be discreet enough that people wouldn't
even know that you had a PC (out of sight, and out of sound).

I've seen companies that build special furniture to receive a PC, but
it's always just a spot into which a standard cabinet can be fitted.
I haven't found anyone who builds PCs directly into furniture, walls,
etc.

Maybe there's no much demand for easy access. I'm the type who would
like to see subfloors and false ceilings with open cable trays and
access

Why not use a refrigerator as your case, it has a handy light when you open
the door. Your components would be as cool as you wanted and you could keep
your beers in there too.

--
For my own part, I have never had a thought which I could not set down
in words with even more distinctness than that with which I conceived
it. There is, however, a class of fancies of exquisite delicacy which
are not thoughts, and to which as yet I have found it absolutely
impossible to adapt to language. These fancies arise in the soul, alas
how rarely. Only at epochs of most intense tranquillity, when the
bodily and mental health are in perfection. And at those weird points
of time, where the confines of the waking world blend with the world of
dreams. And so I captured this fancy, where all that we see, or seem,
is but a dream within a dream.