We propose an original method to reduce a radiation dominated heat transfer problem. To that end, the Amalgam Reduced Order Modal Model (AROMM) method, which preserves the integrity of the geometry, is coupled to the classical radiosity method. The treated application is a complex titanium piece heated by two radiant panels placed in a furnace. The AROMM method reduces by a factor 100 the computation time needed to obtain the solution, while keeping an average error below 0.1%. These very good performances open the way for control or identification procedure in a reasonable time for these kind of applications. (C) 2019 Elsevier Ltd. All rights reserved.