Net Calorific Value, (NCV)
The heat generated by the complete combustion of a unit volume of gas in oxygen, excluding the heat which would be recovered by condensing the water vapour formed. Net Calorific Value is usually seen as a measure of the effective heat produced rather than the total heat in the gas. Also known as Lower Calorific Value or Lower Heating Value. For natural gas, typically 10% lower than the GHV or HHV. See also Gross Calorific Value.