Caloric materials are considered as one of the most promising fields of solid state research when it comes to revolutionize cooling technologies. This challenge is important as we spend in Europe more than 15% of our energy to refrigerate food or cool down our houses. Therefore any new technology must be energy efficient. And it turns out that Electrocaloric (EC) materials – temperature change triggered by electric field – are particularly well suited to high efficiency. Consequently, the objective of CAMELHEAT is to identify the material parameters inducing high efficiency in EC systems. This objective raises three scientific questions. 1) What are the EC materials with the largest variation of temperature? 2) What are the EC materials with the highest materials efficiency? 3) How heat exchange occurs in EC materials?90% of the literature is focused on the first question, which means that the best materials have already been identified (relaxors and antiferroelectrics). On the contrary, the questions addressing energy efficiency and heat exchange in EC materials have been largely overlooked, though they are equally important when it comes to EC systems. We will focus on these two last questions in CAMELHEAT.Our approach consists in choosing three excellent EC materials (Pb(Sc,Ta)O3, PbZrO3 and Ba(Zr,Ti)O3) of different sizes, shapes and architectures (bulk, thick and thin films, multilayer capacitor structure). We will study their materials efficiency, which is the ratio of electrical work over the heat generated by the EC effect. We will also study how to extract heat from these EC materials either by conduction or convection. We will then combine our findings to identify the materials parameters enabling high efficiency in future EC systems, which is the ultimate goal of CAMELHEAT. The originality of this project is to address two important scientific questions on the roadmap towards EC systems, namely what are the EC materials with the highest materials efficiency and how heat exchange occurs in EC materials.