reverberatory-type furnace in which metal is melted by heat from fuel burning at one end of the hearth, passing over the stack at the other end while heat is also reflected from the roof and sidewalls (see: reverberatory furnace), otsetoimeleekahi (kiirgusahi), milles metalli sulatus toimub kütuse põlemissoojuse toimel ahju ühes pooles ning samuti ahju pindadelt peegeldunud soojuse toimel (vt kiirgusahi)