The formula to calculate the latent heat of vaporization in a biomass furnace is:

\[ Q_l = m \cdot H_{fg} \]

Where:

• \(Q_l\) is the latent heat of vaporization in KCal/hr.
• \(m\) is the mass of material in kilograms (kg).
• \(H_{fg}\) is the heat of vaporization of material in KCal/kg.