Warpspeed
Solar Wizard
I really do not know, but historically the "ton" with regard to refrigeration plants was and is definitely tied to how much ice was involved, and that is a fact.The latent heat of ice to water transition is 144 btus/ pound. A ton is 2000 lbs
To melt a ton of ice it would have to absorb 288000 btus.
Maybe tons were smaller back then.
I suppose its like one horsepower.
Comparing a genuine hairy horse to a 1Hp motor directly is difficult.
But James Watt did that, and the horsepower has since become the recognized unit.