Experimental characterization of airflow, heat and mass transfer in a cold room filled with food products

• Experimental investigation was performed in a cold room filled with 4 apple pallets.
• Results allow the interpretation of airflow, heat and water exchanges.
• Cooling rate and temperature heterogeneity were observed.
• The load can be divided in two zones, rear and front loads.
• High temperature and long cooling rate were measured in the front pallet.

Temperature and moisture heterogeneity, with non-uniform airflow in cold rooms was observed in several studies. This heterogeneity can lead to a deterioration of food quality and safety. Heat and mass transfer in cold rooms is a complex phenomenon because of the presence of the product (airflow modification, heat of respiration…) and the coupling between heat transfer and airflow. Temperature, velocity, humidity and heat transfer coefficient measurements were carried out in a ventilated cold room filled with four apple pallets. The front pallets near the cooling unit were submitted to higher air temperatures compared to the rear ones, leading to product cooling rate and temperature heterogeneity. The experimental results allow the understanding of mechanism of airflow as well as heat and water exchanges between product and air.