CEN/TC 89/WG 1 - Thermal bridges and surface condensation

Part 2 of this standard sets out the specifications on a 2-D geometrical model of a linear thermal bridge for the numerical calculation of the linear thermal transmittance of the linear thermal bridge and the lower limit of the minimum surface temperatures.

Part 1 of this standard sets out the specifications on a 3-D and 2-D geometrical model of a thermal bridge for the numerical calculation of: - heat flows in order to assess the overall heat loss from a building; - minimum surface temperatures in order to assess the risk of surface condensation. These specifications include the geometrical boundaries and subdivisions of the model,the thermal boundary conditions and the thermal values and relationships to be used.

This standard deals with simplified methods for determining heat flows through discrete linear thermal bridges which occur at junctions of building elements. It is not applicable to thermal bridging associated with window and door frames or curtain walling. It specifies requirements relation to thermal bridges catalogues and manual calculation methods, and provides a limited number of tabulated default values of linear thermal transmittances.