The increasing pressure of society to decrease energy consumption and to enhance
energetic efficiency has lead to search novel technologies to accomplish it. Notwithstanding the increasing electricity production of renewable energies, it is a fact that
the energy expenses can be drastically reduced in most areas. Among these areas,
cooling systems stand out for being energetically inefficient. Furthermore, both economical and energy cost of such systems are increasing due to the global warming,
which is aggravated by the energy production for them, making a loop that is increasingly damaging the environment.
A solution to this problem has emerged under the name of radiative cooling,
which is a physical phenomenon by which any terrestrial object losses heat in form
of radiation that is sent to outer space. This process can be explained by black body
radiation theory and the atmospheric window. The former states that any object at
some temperature above 0 K radiates energy at all wavelengths, with its radiation
peak and spectral location modulated by its temperature. The latter is a frequency
band in which the atmosphere is transparent to radiation, making possible for waves
at certain frequencies to cross freely. These phenomena allows a direct heat transmission between earth and space, which is cold and almost infinite, making a great
storage for excess warmth without wasting energy in the process.
In this work, it has been studied one of the main technologies that can implement radiative cooling in practice, metamaterials, with the aim to understand how
to improve its associated problems of manufacturing and design for radiative cooling applications. In Chapter 1, the fundamentals of radiative cooling are introduced
along with the state of the art. Then, Chapter 2 presents the materials used in the
literature and in this work to develop later analytical models for thin film multilayered metamaterials and a possible way to automatically design them. To better understand the analytical developments, two appendices introducing the underlying
theory and equations are included. Also, the software used in this work is presented.
Finally, the performance and analysis of three different radiative cooling devices is
exposed in Chapter 3, one of them using the materials and methods of Chapter 2.Máster Universitario en Ingeniería de Telecomunicación por la Universidad Pública de NavarraNafarroako Unibertsitate Publikoko Unibertsitate Masterra Telekomunikazio Ingeniaritza
