Abstract The formulation of a mathematical model that allows simulating the operation of chemisorption refrigeration systems that use medium and low temperature thermal sources such as waste heat and have the purpose of increasing the energy efficiency of industrial and/or residential applications, is a prerequisite to design and facilitate the use of these systems. Such model is described here and is intended to evaluate the heat transfer inside of chemisorption reactor for refrigeration system that can operate with a metallic salt (sorbent) mixed with expanded graphite and NH 3 as refrigerant fluid (adsorbate). The effectiveness of the model is validated through experimental results obtained for a SrCl 2 /NH 3 pair allowing to postulate, a kinetic and thermal model that can be adapted to sorbent/adsorbate pairs of the same type operating under various conditions and thus quantify how operational variables affect the performance parameters of these systems. To this end, the impact of the cycle time and reactor radius on the specific cooling power (SCP) and the coefficient of performance (COP) is measured, concluding that these operational variables exert effects of an opposite nature on the SCP and COP of the system.