What is the standard unit of thermal energy?

Thermal energy is typically measured in several units, and among them, the British thermal unit (BTU) is widely recognized, especially in heating and cooling applications. A BTU is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. This makes it particularly useful in practical applications within the field of power engineering, where heating and cooling systems are evaluated.

While joules, calories, and kilowatts are also valid units of thermal energy and power, respectively, the BTU has a strong association with the energy required in heat transfer processes, particularly in the context of human comfort and HVAC systems. This makes it a common choice for engineers working with thermal systems in both residential and industrial applications.

Joules are the standard unit of energy in the International System of Units (SI) and can also be used to express thermal energy. Calories are another unit that is commonly used to measure thermal energy, particularly in food science and chemistry, reflecting heat absorbed or released during reactions. Kilowatts, on the other hand, measure power, which is the rate of energy transfer rather than a direct measure of thermal energy itself.

Given the context in power engineering and the standard practices in thermal management and measurement