Absorption Refrigeration Using Ammonia-Water: Design, Experimentand Comparative Evaluation

This paper proposes, designs, builds and experimentally evaluates a small-scale solar-driven absorption refrigerator that uses ammonia (NH3) as refrigerant and water (H2O) as absorbent. The experimental campaign compares three energy-supply configurations: (i) grid connection (CFE), (ii) an off-grid photovoltaic (PV) system, and (iii) a Fresnel-based photothermal concentrator. Key metrics (generator and evaporator temperatures, coeffcient of performance (COP), stability) are presented and discussed. Major conclusions and practical recommendations for rural vaccine/medicine storage applications are provided.