The standard available heat represents the net heat available for the process after accounting for flue gas losses and combustion air preheat. It is the sum of the heat input, air correction (negative for losses), and combustion air correction (positive for preheat credit).

\begin{equation}\label{eq:o2-enrichment-standard-available-heat} AH_{std} = Q_{in} + AC + CAC\end{equation}

Symbols

\(AH_{std}\)	Standard available heat \([\unit{ \percent}]\)
\(Q_{in}\)	Heat input \([\unit{ \percent}]\)
\(AC\)	Air correction \([\unit{ \percent}]\)
\(CAC\)	Combustion air correction \([\unit{ \percent}]\)