The document specifies rules for the calculation of heat transfer ralated propterties of building equipment and industrial installations unter steady-state conditions, assuming one-dimensional hea flow. Within the limitations given, these methods can be applied to most types of industrial thermal insulation heat transfer problems. The document gives methods used for industrial thermal insulation caculations not covered by more specific standards. In applications where precise values of heat energy conservation of (insulated) surface temperature need not to be assured, or where critical temperatures for dew formation are either not approached or not a factor, these methods can be used to calculate heat flow rates.