Assume you have something like a warehouse with a
concrete floor but
no warehouse-wide cooling situation. Is it feasible to build a small
climate controlled room inside this larger structure? Where do you
get the necessary A/C equipment for such a thing?
Sure.
and while you are at it, you can blow additional filtered air into that
room so that there is a very slightly higher pressure in your room than
the outside space. Then any leaks are outwards, and you can have
significantly cleaner air in it of hard drive repair, etc.