I have difficulty in understanding how can the relative humidity of a mixture of air and water can be 100%. I understand that places like where i live have high relative humidity, so the place is more humid (rain forest) than deserts, for exemple. But an evaporator, in an air conditioning system, removes the water from the air passing in and elevates the relative humidity of it. So why does a mixture containing, for example, 50% of relat. humidity can lose water mass from it and have a highier relat. humidity level?