How is feedwater heating duty calculated?

For a sensible-heating screen, duty equals feedwater mass flow multiplied by specific heat and the feedwater temperature rise.

Boiler Feedwater Heating Duty Calculator

Calculate sensible feedwater heating duty, annual thermal energy and steam-equivalent heating load.

Inputs

Feedwater flow (kg/h)Inlet temperature (°C)Outlet temperature (°C)Water Cp (kJ/kg·K)Hours/yearSteam latent heat (kJ/kg)

Results

Feedwater heating duty 697.67 kW

Steam-equivalent heating 1141.64 kg/h

Annual thermal energy 4186000.00 kWh

Temperature rise 60.00 °C

Method, assumptions & example

Duty = mass flow × Cp × temperature rise. A 10,000 kg/h feedwater stream heated from 30°C to 90°C needs about 698 kW sensible duty with Cp 4.186 kJ/kg·K. Steam equivalent is an energy screen; actual heaters require steam-table enthalpies and drain/subcooling checks.

FAQs

Is this a final design calculation?

No. Use it for transparent screening and verify equipment, controls and thermodynamic properties against site/OEM data.

What units are used?

The inputs state practical SI units explicitly and outputs are normalized to kW, kWh and kg/h where applicable.

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Last updated: 17 September 2026