Gas
LPG / fuel mass consumption
- where
- fuel mass rate (kg/s; the calculator shows kg/h)
- heat / power rate (W; any unit you pick is converted)
- fuel calorific value on stated basis (J/kg; any unit you pick is converted)
Explain this equation
Works out how many kilograms of fuel an appliance burns per hour, typically LPG. Use it to estimate cylinder or bulk tank consumption from a known heat input.
P is the heat input rate. cv here is a mass-based calorific value: the energy released by burning one kilogram of the fuel, on a stated gross or net basis. ṁ is the mass of fuel used per second, shown per hour.
Dividing power by energy per kilogram leaves kilograms per second. MJ/kg and kW are converted to SI internally so the units cancel cleanly, then multiplied by 3600 for kg/h.
Sense check: 24 kW at 46 MJ/kg is about 1.9 kg/h, so a 47 kg propane cylinder would last roughly 25 hours at full fire. Double the load and the consumption doubles.
Watch out: use fuel data from the supplier and match the gross or net basis of the appliance input. This does not size cylinders, regulators or vaporisation capacity.
Enter your values to see the result.
Good to know
Enter the supplied fuel data. This does not size cylinders, regulators, vaporisation capacity or gas pipework.
Sources
Results are arithmetic only. Worked examples are not recommended design settings. This library does not provide automatic gas pipe selection, live gas tightness tests, purging procedures, combustion acceptance limits, installation approval or commissioning certification. Manufacturer data and the applicable current method remain essential.