SUMMARY Summer air conditioning represents a growing market in commercial and residential buildings. Solar energy is a very interesting energy source because of its advantages. Instead of a compressor system, which uses electricity, an absorption cooling system needs only heat produced by a solar collector plant. Furthermore, Reunion Island has a high solar energy potential. The yearly average solar-radiation and is 5.4 kWh/m²/day. This paper presents a solar-powered, single stage, absorption cooling system, using a water–lithium bromide solution. The first part of this work deals with the dynamic modeling of an evacuated tube collector used for the simulation of heat production. In a second part, simulation and optimization of the system has been investigated in order to determine the optimum of solar collector plant surface, storage tank volume and nominal capacity of the absorption chiller. A new building code was added under TRNSYS16, to have dynamic coupling between building loads and cooling production.