2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/19886A non-reciprocal phonon model for microwave or optical isolators is considered. It gives a simpler framework to further investigate the formerly argued possibility for a heat transfer between black bodies at common temperatures. While the non-dissipative device retains the Detailed Balance property, the presence of dissipation breaks it. This property allows a net transfer of heat between the two black bodies at common temperatures, whenever the absorptive elements are at lower temperatures than the one being common to the bodies.6 pages,3 figures, contribution sent to the I International Conference on Quantum Limits of the Second Law (29-31 July, 2002), University of San Diego, San Diego, CAStatistical MechanicsDisordered Systems and Neural NetworksMesoscale and Nanoscale Physicstext