What is the calorific value of gas?

That quantity of energy corresponds to the heat released when it burns. So calorific value is a unit of measurement that can be used to compare the efficiency of one form of energy with another. The higher the calorific value, the more efficient it is at producing heat.

The calorific value of gas is not always the same. It can vary with temperature and pressure, but also its composition, which in turn depends on where it comes from.