Abstract: The invention relates to a recuperator having an improved core within the primary heat transfer surface. This core, by its unique construction, achieves a combination of reradiative and convective heat transfer which outperforms either of these separate modes while maintaining a low pressure loss. The core consists of a series of radial plates between which are a series of triangular baffles arranged at an angle with the horizontal of 45.degree. to 70.degree.. The baffles intercept the flow of flue gas and gently channel the flow of gas into a swirling pattern, thereby enhancing convective heat transfer while maintaining low pressure loss. The staggered triangular baffles also tend to reflect radiation that would otherwise be lost back to the primary heat transfer surface.