The latent heat recovery is calculated by multiplying the heat input by the latent heat fraction. This represents the additional heat recovered when water vapor in the flue gas condenses to liquid water, releasing its latent heat of vaporization.

\begin{equation}\label{eq:air-water-cooling-flue-latent-heat-recovery} Q_{latent} = Q_{in} \cdot f_{latent}\end{equation}

Symbols

\(Q_{latent}\)	Latent heat recovery \([\unit{ \mega\btu\per\hour}]\)
\(Q_{in}\)	Heat input \([\unit{ \mega\btu\per\hour}]\)
\(f_{latent}\)	Latent heat fraction \([\unit{ \unitless}]\)