Nowadays, it's true they usually use watts. But not too long ago (and still very common in office-building server rooms) they use "tons of refrigeration", whic

Nowadays, it's true they usually use watts. But not too long ago (and still very common in office-building server rooms) they use "tons of refrigeration", which takes its name from the amount of power it takes to phase change a ton of water in 1 day. It is 12k BTU/h.