The Coefficient of Performance (COP) for a thermally driven cooling system is defined as the cooling output divided by the heat input.  For a liquid-desiccant air conditioner the heat input is closely tied to the amount of water that the desiccant has absorbed.  It is useful to compare the latent COP of different liquid-desiccant air conditioners, i.e., the amount of heat needed to remove water from the desiccant, rather than the overall COP.  When the liquid-desiccant air conditioner's water-cooled conditioner is supplied with water from a cooling tower, the overall COP will typically be higher than the latent COP when ambient wet-bulb temperatures are low, and lower when ambient wet-bulb temperatures are high.