Design and construction of a low cost solar chiller, with calorimetric assessment of the adsorbent bed

This paper discusses the design and construction of a prototype refrigeration system that uses solar energy as a heat source to drive an adsorption refrigeration cycle. The system is designed to be low cost and provide cooling for food preservation in rural, off-grid locales. Materials and construction methods were selected for their low cost, availability and compatibility with the adsorbent and refrigerant. The adsorbent bed was designed to improve heat transfer, allowing the mass of adsorbent in the system to be reduced to less than one fifth of the mass in many "standard" solar refrigerators. This allows shorter cycle times, and makes the system more compact. To further reduce size, the solar absorber was also incorporated into the adsorbent section, allowing heat to be directly transferred to the adsorbent by thermal conduction. This paper also makes estimates of system performance based on data obtained using a previously developed calorimeter.