Furnace Heat Load Calculator
Furnace Heat Load Calculator: Determine Required Heating Duty
Sizing a furnace or process heater starts with knowing the heat load: the rate of energy required to raise a material or fluid stream from an inlet temperature to a target outlet temperature. This calculator computes that load directly from mass flow, specific heat, and temperature rise.
The Formula
Heat Load (kW) = Mass Flow(kg/hr) × Specific Heat(kJ/kg·K) × Temp Rise(K) / 3600
Worked Example
A process stream flows at 5,000 kg/hr with a specific heat of 4.18 kJ/kg·K and needs a 60°C temperature rise.
Heat Load = 5,000 × 4.18 × 60 / 3600 = 348.33 kW
How to Use This Calculator
- Enter the mass flow rate of the material or fluid in kg/hr.
- Enter its specific heat capacity in kJ/kg·K.
- Enter the required temperature rise in Kelvin (or °C, since the interval is equal).
- Click Calculate to see the furnace heat load in kW.
Related Calculations
Feed this result into the Furnace Volume Calculator and Furnace Efficiency Calculator to complete your furnace sizing.