A refrigeration system includes a housing having a top, a bottom, first and second opposed sides, and containing an atmosphere; a conveyor apparatus including a self-stacking, self-supported, spiral conveyor belt and a drive mechanism, wherein the conveyor belt includes a plurality of tiers and is at least partially disposed within the housing such that the conveyor belt can travel within the housing from the bottom towards the top of the housing or from the top towards the bottom of the housing; and an atmosphere circulation apparatus having at least one blower in communication with the atmosphere for circulating at least a portion of the atmosphere within the housing from proximate the first opposed side to the second opposed side and back towards the first opposed side, wherein the portion of the atmosphere circulated passes over the conveyor belt in a crossflow manner at least once.