A system for purifying and pre-conditioning intake air in an air conditioning unit comprises an energy exchange unit having an air inlet, an air outlet, a primary air flow running from the air inlet to the air outlet, and an active energy exchanging element or elements, and at least one spray washer having at least one nozzle, the spray washer positioned between the air inlet and the next active element, wherein the at least one spray washer is configured to dispense droplets of a fluid into the intake air from the at least one nozzle. A method for purifying and pre-conditioning intake air in an air conditioning unit is also described.