The efficacy of a four-bed adsorption chiller has been studied experimentally with respect to a simple but yet effective passive heat and mass recovery schemes. It substantially improves the adsorption chiller COP by as much as 30% over a broad range of cycle time with a wide heat source, coolant and chilled water temperatures. Two schemes have been considered here: Firstly, only the mass recovery is achieved by pressure equalization between the concomitantly cooled adsorber and heated desorber, exploiting the intrinsic vapor-uptake potential by pressure swing that remains in the adsorbent at the end of a half-cycle. Secondly, when both the heat and mass recovery schemes are employed at a rating point of maximum cooling capacity, the chiller COP could increase further to as much as 48%. These improvements are performed without additional hardware changes to the adsorption chiller. (c) 2006 Elsevier Ltd. All rights reserved.