Lambda is a value that expresses a material's ability to limit energy losses. The average lambda value is the parameter used for calculating the heat loss incurred in pipe networks used for transporting gases and liquids from one place to another, and for distribution.

Lambda values are calculated on the basis of a section of pipe with specific dimensions. However, they can also be used to calculate heat losses for pipe sections with other dimensions, if these are manufac-tured in the same way.