Btu (15.8°C, Canada)
The Btu (15.8°C, Canada) is a variant of the British thermal unit defined as the energy to raise the temperature of one pound of water by one degree Fahrenheit at a starting temperature of 15.8°C. This definition is tailored to Canadian standards reflecting the country's historical reliance on both imperial and metric.
Btu (mean)
Btu (mean) is a unit of energy used primarily in the United States defined as the heat required to raise the temperature of one pound of water from 59°F to 60°F under standard atmospheric pressure.