It warms up when it is compressed, but cools when it is decompressed, i.e., released to atmospheric pressure.
"It warms up when it is compressed, but cools when it is decompressed, i.e., released to atmospheric pressure."
Yes, I know that.
But it also depends on how fast it is decompressed. Ever use a plastic welder? It uses compressed air released slowly through a very small tube. It gets very hot at the tip source. It will blister your skin very fast.
Using compressed air for air conditioning is useless. Might as well roll down the window.