A high efficiency airflow management system can be used to reliably and consistently draw air through palletized product stacks with a minimum of energy expenditure. A racking system is provided with a grid of pallet bays separated from an air plenum/chamber by a wall having an airflow opening for each pallet bays. An air seal is formed at the periphery of each opening by resiliently flexible side seals and a top seal to form a highly airtight interface between the pallet assembly and the adjacent airflow opening. When a pressure differential is developed between the chamber and the pallet bay, air is efficiently drawn substantially exclusively through the pallet assemblies with minimal leakage. The flexible sealing arrangement accommodates pallet assemblies with unevenly stacked rows of cases without significant loss of system efficiency.