【正文】 dification and summer “cooling” with the help of thermal mass. Paul Wallot, the architect of the building, responded as follows when asked how the arts of architecture, painting, sculpture are related: ”Today some have spoken of three ?sister arts?, architecture, painting, and sculpture. But in our time there is a fourth art which has joined theses, the art of engineering. A steam engine, in my opinion, is the highest artistic achievement in that purpose and means are bined to perfection. In any harmonious collaboration of all the arts, I would include the art of engineering. I propose a toast to a melting together of all four arts, to their unity.” Hydronic Radiant Heating Building Systems in History Thermal labyrinths, cavities and channels underneath useable floor space are known from the earliest structures of the Roman Empire. The bination of “forced” warm air and the thermal storage capacity of heavy mass structural building elements, such as brick and concrete tunnels, walls, floors, and ceilings is wellknown as “hypocausts”. These systems of thermal storage were used in the Roman bath, the “Thermae”. Bathing in Roman times was a lengthy and social event, lasting several hours and involving a trip through most of plex, including the “Caldarium”, (warm water application), and the “Frigidarium”(the cold water pools). The heated rooms were each warmed by one or more furnaces, and a sophisticated system of hypocausts supported their floors. The hypocausts were made of piers of stacked clay disks (approximately 0,30m in diameter) that were stacked oneandahalf meters high, and were covered with mortar, large square tiles, and cut marble slabs, forming the floor of these rooms. Furnaces heated the hypocaust channels under the floor slab, which were sufficiently warmed to heat up the entire room above. The furnace exhaust air escaped through numerous flues in the wall, providing additional heating for the whole room. In later Roman design, terracotta pipes for more control airflow were introduced. Similar simple technologies were used in traditional residential buildings in Korea for thousands of years. Radiant floors in modern times are sufficiently known as either closed, indirect or opendirect heating systems utilizing a high efficiency boiler for space and warm water heating. They are widely used throughout the building industry. In Europe the use of hydronic heating systems in residential and mercial applications is a mon technology and used costeffectively. After World War II, . GI?s brought the technology back from the campaigns in Germany to the western hemisphere were it was only used reluctantly. In Europe too, hydronic heating was more or less abandoned after some application in the late 50s. However, user plaints about allair systems changed the designers39。 attitude towards the technology, which led to new hydronic system designs with better control. The use of the same piping, typically manufactured of copper, synthetic rubber such as EPDM, and plastics such as polyethylene, polypropylene and polybutylene for the circulation of cold water is today still relatively unknown and faces certain resistance not only by clients but also the design munity. Radiant Cooling A corecooled ceiling is the cooling equivalent of a floor heating system. In the radiant cooling system, cold water is circulated through plastic piping. These pipes can be embedded into the slab either closer to the floor or at the ceiling level. If in bination with radiant, warm water piping, utilizing the same pipes, a location in the