commonly used unit of measurement for the capacity of their chillers, with 12,000 BTU/hr. Although, one must admit that some of them follow a rather loose set of arithmetic rules.
What's interesting to me is that every engineering reference I've been able to dig up equates 1 HP to 2540 BTU/hr (give or take a few BTU).
The reference works and engineering tables do commonly equate 1 hp to 12,000 tons refrigeration, but not 12,000 BTU/hr. Tons Refrigeration is a still used but somewhat antiquated standard of measure for chilling capacity, having originated as a measure of the amount of ice a device could produce in a fixed period.