As a process engineer dealing with gas project, I usually involve in these terms, higher heating value (HHV) and lower heating value (LHV). Do you know the differences between these two?
In simple words, higher heating value (HHV) includes energy used to vaporize water. While lower heating value (LHV) excludes energy used to vaporize water.
Which water?
Water contained in the original energy form or created during the combustion process.
If we put them into equation, then it will be like this.