Energy
Waste Heat Recovery Calculator
Estimate recoverable sensible heat, annual energy recovery and cost savings from a hot gas or liquid stream.
Use a representative average value over the temperature range.
Uses the same temperature unit selected above.
Fraction of the available sensible heat that can actually be recovered for useful service.
Optional. Enter the cost of the energy source displaced by recovered heat.
Recoverable Heat
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Estimated useful sensible heat recoverable from the waste stream.
Available waste heat
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Recoverable heat
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Temperature reduction
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Mass flow rate
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Available heat per unit mass
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Annual available waste heat
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Annual heat recovered
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Annual cost savings
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Method:
Available sensible heat is calculated from:
Q =
ṁ × cp × ΔT
where:
ṁ = mass flow rate
cp = specific heat capacity
ΔT =
Waste Stream Temperature − Target Outlet Temperature
With mass flow in kg/s and specific heat in kJ/kg·K, the result is directly obtained in kW.
Recoverable heat is:
Qrecovered =
Qavailable × Heat Recovery Efficiency
Annual recovered energy is:
Energy Recovered =
Recoverable Heat × Operating Hours
Annual cost savings, when an energy cost is entered, are:
Cost Savings =
Recovered Energy × Energy Cost
This calculator considers sensible heat only.
It does not include latent heat from condensation, evaporation or other phase changes. It also does not account automatically for heat-exchanger pinch temperature, fouling, radiation losses, corrosion limits, dew-point constraints or variations in flow and temperature.
For gas streams, specific heat may change significantly with composition and temperature. Use a representative average specific heat or detailed property data for higher-accuracy calculations.