The present invention provides an air conditioning system that is capable of treating a conditioned space by treating outdoor air from outside the conditioned space and return air from inside the conditioned space, and mixing the outdoor air with the return air to form supply air for the conditioned space, the air conditioning system including an outdoor air latent cooling treatment stage configured to provide parallel airflow with a return air sensible cooling treatment stage, and a means for mixing outdoor air with return air to form conditioned space supply air, wherein the outdoor air latent cooling treatment stage includes at least a dehumidification heat exchanger, combination pre-cooling and heat reclaim heat exchangers, and a heat transfer pump, and the return air sensible cooling treatment stage includes at least a sensible cooling heat exchanger.