Lithium-bromide systems can play a strategical role in the recovery of unused low exergy level energy source, in particular in the current context where the priority relationship between initial investment and running constraints (cost and electricity consumption reduction/deletion) have shifted. Despite this strategical interest and, among the low Coefficient of Performance, the systems are bulky and the investment cost is high compared to conventional system. To improve the performance of these system, the project proposes to study a new concept of generation of liquid films in the wall allowing to reduce considerably their thickness and to improve the performances of boiler by taking advantage of the boiling phenomenon which can occur there. The application targeted is a lithium-bromide absorption heat-pump of type II driven by a low exergetic level source (˜ 40°C). By the design of modular experimental channels, the development of a new laser-induced fluorescence methodology to access the volumetric mean temperature and LiBr concentration, complex phenomena occurring inside the experimental set-up will be analysed, characterised and modelized. In particular, the impact of the confinement of the fluid inside the channel, the working pressure and the wall superheat on the exchanger performances will be analysed and quantifyed. Novel asymptotic models to capture the drying dynamic of water and water-bromide solution, as well as the interplay between heat and mass transfer will be developed. Tools and performances maps developed in the context of this project will then be exploited to design a compact low-pressure water-based heat- exchangers and a rational design of a LiBr boiler will be proposed.