ISO 11855-1:2012 specifies the basic definitions, symbols, and a comfort criteria for radiant heating and cooling systems.

ISO 11855-1:2012 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 panel systems with open air gaps which are not integrated into the building structure.

ISO 11855-1:2012 also applies, as appropriate, to the use of fluids other than water as a heating or cooling medium. ISO 11855-1:2012 is not applicable for testing of systems. The methods do not apply to heated or chilled ceiling panels or beams.