Sensible Heat Rate Calculator

Calculate steady fluid heating or cooling rate, heat-capacity rate and stated-period energy from mass flow, specific heat and temperature change.

This calculator is for sensible heating or cooling with no phase change. Use values at a consistent representative temperature.

Sensible heat-transfer rate83.72 kW285,664.528 Btu/h
Heat-capacity rate (ṁcₚ)4.186 kW/K7.935 Btu/(h·°F)
Energy over stated duration83.72 kWh285,664.528 Btu

Important: this does not account for phase change, heat loss to surroundings, pressure effects or a strongly temperature-dependent specific heat. The energy result assumes the entered flow, specific heat and temperature change persist for the stated duration. Use enthalpy data for steam, refrigerants, boiling, condensation or large property changes.

Method and variables

Sensible heat rate: Q̇ = ṁ × cp × ΔT. Heat-capacity rate: ṁcp.

  • ṁ — mass flow rate
  • cp — specific heat capacity at the representative operating condition
  • ΔT — temperature rise or drop through the stated process

Worked example

Water flowing at 1 kg/s with cp = 4.186 kJ/(kg·K) and a 20 K temperature rise requires 1 × 4.186 × 20 = 83.72 kW. At that same constant duty for one hour, the corresponding energy is 83.72 kWh.

Using the duration result

The duration field converts the calculated heat rate to energy only. It is a constant-condition scenario; it does not model ramp-up, storage, pipe loss, changing flow, plant cycling or billing tariffs.

Important limits

Use enthalpy rather than this relation for boiling, condensation, steam, refrigerants or another phase-change process. Check fluid properties at the expected operating condition if temperature or pressure varies substantially. This calculator does not account for heat loss to surroundings or pressure-drop effects.

Related tools

LMTD Heat Exchanger Calculator · Heat Energy Calculator · Heat Transfer Calculators

Frequently asked questions

What equation does the sensible heat rate calculator use?
For a fluid with no phase change, it uses Q̇ = ṁ × cp × ΔT: mass flow rate times specific heat capacity times temperature change.

When should I use enthalpy instead of cp times temperature change?
Use enthalpy data for phase change, steam, refrigerants, boiling, condensation or a process with substantial property variation. The simple sensible-heat relation is not a phase-change model.

What does the duration result represent?
It multiplies the calculated heat-transfer rate by the operating duration you enter. It assumes the flow, specific heat and temperature change remain constant throughout that period.