Absorption experiments were conducted to investigate the influences of fin parameters such as winding pattern, height and pitch on heat and mass transfer characteristics in an absorber with a spirally finned tube. A double-stacked type tube showed better performance than a single-stacked type. In the single-stacked type, film heat transfer coefficient and mass transfer coefficient increased with increasing fin height, and an optimum fin pitch was found to exist. The fin winding pattern had a bigger effect on heat transfer rate than on absorption rate. From a practical standpoint, a comparative study was conducted on heat and mass transfer performance based on the weight of the finned tube. From absorption rate and heat transfer rate per tube weight, it was demonstrated that the single stacked fin with fin height of 8 man and fin pitch of 8.6 mm or 10.6 mm has the best performance. Boost temperature characteristics increased with increasing weight of the fir-finned tube, reaching 26 K for the double-stacked type and 23-25 K for the single-stacked type.