Adsorption chiller technology is one of effective means to convert waste thermal energy into effective cooling, which substantially improves energy efficiency and lowers environmental pollution. This article develops an improved lump-parameter design model for multi-bed silica gel-water adsorption chillers. It is validated by experimental results stemming from a four-bed silica gel-water adsorption chiller at various operating conditions. We found that the performance predictions from this model compare favourably with experimental results. At rated conditions and over a wide range of cycle times, both the cooling capacity and COP can be predicted to within 10%. This indicates that the model can be used confidently as a design tool for multi-bed adsorption chillers.