DIN EN ISO 11855-8:2026-05

DIN EN ISO 11855-8 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. 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. This document (EN ISO 11855-8:2023) has been prepared by Technical Committee ISO/TC 205 "Building environment design" in collaboration with Technical Committee CEN/TC 228 "Heating systems and water based cooling systems in buildings", the secretariat of which is held by DIN (Germany). Since November 2024 the EN ISO 11855 series of standards at CEN has been assigned to CEN/TC 130 "Space heating and/or cooling appliances without integral thermal sources", the secretariat of which is UNI (Italy). The responsible national standardization committee is Working Group NA 041-01-69-15 AK "Integrierte Flächenheizungen und -kühlungen (SpA CEN/TC 130/WG 9 und ISO/TC 205/WG 8)" ("Integrated surface heating and cooling (Mirror committee CEN/TC 130/WG 9 and ISO/TC 205/WG 8)") at DIN Standards Committee Heating and Ventilation Technology and their Safety (NHRS).