The total available heat fraction is calculated by adding the available heat fraction (sensible only) to the latent heat fraction. This represents the total fraction of input heat that can be recovered through the condensing heat exchanger, accounting for both cooling the flue gas and condensing water vapor.

\begin{equation}\label{eq:air-water-cooling-flue-total-available-heat} AH_{total} = AH + f_{latent}\end{equation}

Symbols

\(AH_{total}\)	Total available heat fraction (sensible + latent) \([\unit{ \unitless}]\)
\(AH\)	Available heat fraction (sensible only) \([\unit{ \unitless}]\)
\(f_{latent}\)	Latent heat fraction \([\unit{ \unitless}]\)

Note

This total available heat fraction is always greater than the standard available heat fraction because it includes the additional benefit of latent heat recovery from condensation.