A compact and energy efficient air conditioning system is operated with a desiccant material having a high differential adsorption capacity even at lower regeneration temperatures than those in the conventional system. The desiccant assisted air conditioning system comprises a process air path (A) for flowing process air to adsorb moisture from the process air by a desiccant member, and a regeneration air path (B) for flowing regeneration air heated by a heat source to desorb moisture from the desiccant member (103). The desiccant member is arranged so that the process air or the regeneration air flows alternatingly through the desiccant member. The desiccant member is arranged so that the process air or the regeneration air flows alternatingly through the desiccant member. The desiccant member comprises an organic polymer material, the organic polymer material comprising an amphoteric ion exchange polymer having an anion exchange group, a cation exchange group and bridging ligands, thereby exhibiting a high differential adsorption capacity.