"stryped" wrote in message
...
I have a 30x30 metal building. I have no windows. What would be the
best and cheapest way to air condition it? I thought about a window
unit but I have no windows and not sure if cutting the corregated
metal would work right.

Yeah, you might have boucou vibration.

Consider mini-splits.
You can install 2-4 12,000 btu units, sequence them as needed.
Even tho one unit might not cool the whole space, the area *near* the unit
will be markedly cooler than areas farther away -- if you are going to be
working in just one area for some while.
Moveable partitions would help, as well. Or full partitions.

Much quieter than window units, more efficient, etc. They vary greatly in
price, as well, and most seem to have heat pumps.

Also consider ceiling fans, and vents in the roof -- these can greatly
reduce the heating load.
Ceiling fans help in both summer AND winter, perhaps even more in winter.
Ideally, summer/winter fans would not only change rotation, but would be
height-adjustable, as well.

And yeah, insulate!!

You can also paint windows inside yer structure, with a sun, clouds, sky,
etc.... Can really help!
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EA