A no-draught and comfortably warmed up living and working environment is a condition for the satisfaction and health of humans. The thermal comfort is reached if humans feel well in the area. He feels thereby
a pleasant warmth, which surrounds him gently, without him having to deplore course features, the feeling of cold environment surfaces or of dry air. Only a large heat surface with a low surface temperature can produce this ideal condition. Floor and walls are suited for it. They function according to the principle of the radiant heat, which humans feel like mild sunbeams in spring as particularly pleasant.