Compact, low-power absorption cooling supports decentralized refrigeration needs and is positioned here as a sustainable approach within environmental technologies. This paper presents the design, fabrication, and experimental validation of a compact LiBr–H₂O evaporator–absorber, in which a low-energy fan assists in transporting refrigerant vapor from the evaporator to the absorber within a single vertical falling-film vessel. Twelve heat-load phases were tested with the fan OFF/ON, while temperatures, pressures, and flow rates were continuously monitored. The analysis focuses on temperature and pressure separation metrics, as well as a dimensionless separation index. Results show that fan assistance stabilizes thermal and pressure differentials and attenuates oscillations across grouped loads. The most significant benefits are observed at low to intermediate heat inputs, whereas the effect becomes marginal at higher loads, indicating the dominance of natural transport mechanisms. The compact unit remains thermally stable under all tested conditions. These findings indicate that a simple, low-power mechanical enhancement can improve controllability in an integrated evaporator–absorber without complex internal geometries. Protected under a Mexican utility model (IMPI, MX 4573 B), this prototype provides a replicable experimental basis for supporting compact, low-power solutions for sustainable, decentralized cooling in the field of environmental technologies.

This manuscript presents a patent-based engineering case study of a compact LiBr–H₂O evaporator–absorber unit, tracing its progression from conceptual embodiment to laboratory validation through contextualized technology-readiness assessment and bounded data-driven analysis. The study reconstructs three successive prototypes, applies the international Technology Readiness Level (TRL) framework together with the Mexican TRL guideline, and includes an exploratory artificial neural network (ANN) analysis of the validated Prototype III. The results show a maturation pathway: Prototype I corresponded to conceptual embodiment, Prototype II provided proof-of-concept evidence through observable cooling, and Prototype III was a protected, instrumented, and experimentally validated laboratory prototype, conservatively assigned to TRL 4 as the highest level supported by the evidence. The auxiliary ANN gave only a limited approximation of the thermal response (mean test R² = 0.41, dispersion ±0.32), consistent with a single-run laboratory-scale dataset rather than robust predictive modeling. Overall, the study integrates prototype trajectory, intellectual-property protection, TRL assessment, and bounded analysis into a rigorous evaluation of a protected pre-commercial thermal subsystem. Beyond this device, the framework offers inventors, designers, and research groups a transferable reference, letting them build on a documented pathway rather than restarting from the lowest readiness levels and identifying the evidence needed for each TRL transition.

This study reports the thermodynamic performance of a patented compact vertical evaporator–absorber unit for LiBr–H₂O absorption cooling, extending Part I by translating validated prototype data into a rigorous control-volume assessment of coupled transport. Coolant-side calorimetry was used to determine the absorption heat-transfer rate (Q_abs), while a mass–energy balance provided an estimate of the absorption mass-transfer rate (${∆\dot{m}}_{abs}$) across twelve manually imposed thermal-load phases with tagged fan-OFF/ON sub-intervals. Linear trend (slope) analysis was applied to quantify phase-resolved dynamic behavior. Fan assistance produced three load-dependent regimes: (i) stabilization of downward trends under low and zero loads, yielding slope-based relative improvements above 100% in the most critical weak-gradient phases; (ii) acceleration of recovery at intermediate loads; and (iii) moderation of strongly positive drifts at high loads. The global thermal resistance ($R_{th}$) decreased by more than 30% in passive and low-load phases, and Wilcoxon signed-rank tests confirmed statistically significant reductions in most intervals (p < 0.05). Uncertainty contributions and robustness were quantified through an uncertainty budget decomposition and sensitivity analyses, and a subsystem-level normalization (η_EA = Q_abs/Q_in) is reported to support comparisons across loads without invoking cycle COP. Overall, active vapor-flow management using a low-power internal fan widens the useful operating envelope of compact absorbers and provides a validated thermodynamic baseline with practical, regime-aware control guidelines for decentralized low-carbon cooling technologies.