We know that heat is thermal energy into motion of a body to another, it can be concluded that this energy can be measured. Then heat units used to determine the amount of heat which migrates from one body to another.
Calorie - Cal
Britsh Thermal Unit - BTU
BETWEEN THE HEAT UNITS RELATIONS
1 Kcal / h = 3,968 BTU / hr = 4.1858 J / h
TR 1 / h = 12000 BTU / hr
1TR / h = 3000 Kcal / h