Calculator inputs
Formula used
These equations cover phase change, heating, power, and energy loss. Use consistent units before applying any formula manually. The calculator performs every supported conversion before solving automatically.
How to use this calculator
- Select the calculation mode matching your unknown value.
- Choose a preset or enter custom property values.
- Enter the required mass, energy, or equipment data.
- Enable sensible heating when starting below boiling temperature.
- Check pressure, efficiency, and vaporized percentage carefully.
- Select Calculate and review steps, warnings, and conversions.
Editable presets make common calculations faster and easier. Custom inputs support unusual liquids and pressure-corrected data. Verify critical properties using trusted references before final decisions.
Example data
| Example | Mass | Latent heat | Vaporized portion | Phase-change energy |
|---|---|---|---|---|
| Water | 1 kg | 2256.4 kJ/kg | 100% | 2256.4 kJ |
| Ethanol | 0.5 kg | 841 kJ/kg | 100% | 420.5 kJ |
| Acetone | 2 kg | 518 kJ/kg | 25% | 259 kJ |
| Nitrogen | 10 kg | 199 kJ/kg | 80% | 1592 kJ |
| R134a | 3 kg | 216 kJ/kg | 40% | 259.2 kJ |
Common substance reference values
| Substance | Latent heat | Boiling point | Molar mass | Liquid specific heat |
|---|---|---|---|---|
| Water | 2,256.4 kJ/kg | 100 °C | 18.01528 g/mol | 4.186 kJ/(kg·K) |
| Ethanol | 841 kJ/kg | 78.37 °C | 46.06844 g/mol | 2.44 kJ/(kg·K) |
| Methanol | 1,100 kJ/kg | 64.7 °C | 32.04 g/mol | 2.53 kJ/(kg·K) |
| Acetone | 518 kJ/kg | 56.05 °C | 58.08 g/mol | 2.15 kJ/(kg·K) |
| Ammonia | 1,371 kJ/kg | -33.34 °C | 17.031 g/mol | 4.7 kJ/(kg·K) |
| Propane | 356 kJ/kg | -42.1 °C | 44.097 g/mol | 2.5 kJ/(kg·K) |
| Butane | 366 kJ/kg | -0.5 °C | 58.12 g/mol | 2.3 kJ/(kg·K) |
| Nitrogen | 199 kJ/kg | -195.79 °C | 28.0134 g/mol | 2.04 kJ/(kg·K) |
| Oxygen | 213 kJ/kg | -182.95 °C | 31.998 g/mol | 1.67 kJ/(kg·K) |
| Hydrogen | 446 kJ/kg | -252.87 °C | 2.016 g/mol | 9.5 kJ/(kg·K) |
| Mercury | 295 kJ/kg | 356.73 °C | 200.59 g/mol | 0.14 kJ/(kg·K) |
| Refrigerant R134a | 216 kJ/kg | -26.1 °C | 102.03 g/mol | 1.42 kJ/(kg·K) |
| Refrigerant R410A | 233 kJ/kg | -51.6 °C | 72.58 g/mol | 1.55 kJ/(kg·K) |
Reference values describe approximate conditions near normal boiling points. Real properties change with pressure, temperature, purity, and composition. Use verified datasets for safety-critical or regulated engineering work.
Understanding vaporization energy
What latent heat means
Latent heat changes a liquid into vapor without raising temperature. It is measured near a chosen pressure and boiling point. Latent heat drives boilers, condensers, refrigeration, and process design.
Evaporation and boiling
Evaporation occurs at a liquid surface below boiling temperature. Boiling occurs throughout liquid when vapor pressure matches surroundings. Both processes require energy to overcome molecular attractions completely.
Sensible and latent heat
Sensible heat changes temperature before the phase change begins. Latent heat changes phase while temperature stays nearly constant. Total heating often includes both energy contributions in practice.
Assumptions and limitations
Preset properties are approximate values at typical boiling conditions. Actual values change with pressure, purity, and measurement methods. Use verified property data for critical engineering calculations always.
Calculation history
Frequently asked questions
What is latent heat of vaporization?
Latent heat is energy required to vaporize unit mass. The temperature stays nearly constant during ideal phase change. Property values depend strongly on pressure and liquid composition.
How do specific and molar values differ?
Specific latent heat uses energy per unit mass. Molar enthalpy uses energy per mole of substance. Molar mass converts accurately between these two property bases.
Why does heating efficiency matter?
Efficiency accounts for heat lost outside the intended liquid. Lower efficiency increases required supplied energy and operating cost. Real systems lose heat through vessels, piping, and surroundings.
Does operating pressure change the answer?
Pressure changes the boiling temperature and vaporization property value. This calculator records pressure but uses entered property data. Select property values measured near your actual operating pressure.
Can this calculator handle partial vaporization?
The vaporized percentage controls how much liquid changes phase. Sensible heating still applies to the entered starting mass. Remaining liquid equals original mass minus calculated vaporized mass.
How is heating time estimated?
Heating time divides required input energy by heater power. The estimate assumes constant power throughout the heating process. Cycling controls and losses can extend real heating time.
Are the substance presets exact?
Presets provide convenient approximate values for common substances. They are not guaranteed for every temperature or pressure. Replace presets with trusted data for final engineering work.
What happens above the boiling temperature?
Temperature differences may be negative when liquid starts hotter. Sensible heating is then omitted and a warning appears. Cooling or condensation requires a different thermodynamic calculation model.
How is electricity cost calculated?
Electricity cost multiplies input kilowatt-hours by your entered rate. Currency symbols are displayed exactly as you provide them. Taxes and demand charges are not included automatically here.