F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
F28F21/08—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal
F28F21/088—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal for domestic or space-heating systems