prBAS EN ISO 11855-8:2025

This document specifies procedures and conditions to enable the heat flux in electrical surface heating systems to be determined relative to the medium differential temperature for systems. The determination of thermal performance electrical surface heating systems and their conformity to this document is carried out by calculation in accordance with design documents and a model. This enables a uniform assessment and calculation surface heating systems. The surface temperature and the temperature uniformity of the heated surface, nominal heat flux density between electrical heated layer and space are given as the result. The ISO 11855 series is applicable to water based embedded surface heating and cooling systems in residential, commercial and industrial buildings[1]. The methods apply to systems integrated into the wall, floor or ceiling construction without any open-air gaps. It does not apply to ceiling mounted panel systems with open air gaps which are not integrated into the building structure. The ISO 11855 series also applies, as appropriate, to the use of fluids other than water as a heating or cooling medium. The ISO 11855 series is not applicable for testing of systems. The methods do not apply to heated or chilled ceiling panels or beams. [1]  ISO 11855-7 can also be used for electrical heated embedded systems.