Small size absorption refrigerators: a comparison among different solutions in solar feeding applications

Absorption refrigerating machines represent an interesting alternative to compression machines, especially when waste heat or heat produced by solar energy is available; the market is beginning to propose small-size absorption machines especially designed for air conditioning in residential buildings. A recognition of small size absorption refrigerators is reported, with particular emphasis on their performances in the case that the thermal source is constituted by solar energy. The examined machines cover different chilling powers (from 4 to 15 kW) and have different working principles. The study is conducted through the data supplied by manufacturers and collected in the experimental set-up available at the Labs of the University of Perugia; different refrigerators are compared taking into account the most significant parameters such as hot source and chilled water temperature, cooling circuit characteristics, coefficient of performance, weight and dimensions. Energy and environmental advantages deriving from the solar supply are also evaluated.