The work carried out in this thesis aims to contribute to the solution of the sustainability problems of new aircraft, dealing with the thermal control of the avionics that govern the operation of important on-board systems. Although the new electronic components tolerate operating temperatures that are decidedly higher than traditional ones, which, even using advanced design and production technologies, do not tolerate temperatures above 80°C, it is still necessary to dispose of quantities of heat in the order of 1000 – 2000 W to operate safely and reliably. The design of the thermal control system was therefore carried out, choosing what could be the most suitable solution, meeting various requirements: minimum power necessary for its operation, small size and weight, high reliability.