In this work, we propose a numerical approach for modeling surface radiation coupled with heat transfer using an immersed volume method. Our method is inspired by the classical "surface-to-surface" approach, present and largely used in the most of commercial CFD softwares. The major novelty is that the surface-to-surface calculation involves interior faces of the finite element mesh used for flow and heat transfer calculations, whereas a classical surface-to-surface method only involves border faces. An algorithm to detect the faces suitable to take part in the surface radiation is presented first. The basics of surface radiation calculation are then briefly recalled. Finally, the method is tested on several natural convection-radiation benchmark problems. The consistency of the method is demonstrated, by using the proposed method to reproduce the results of a classical body fitted approach. (C) 2019 Elsevier Ltd. All rights reserved.