New type of energy efficient heat exchanger for indirectly cooled display cabinets.

In this study, a completely new type of air-to-liquid heat exchanger, adapted for obtaining good heat transfer performance even at a laminar flow regime on the liquid side has been evaluated in a display cabinet application. The heat exchanger consists of parallel plates, with liquid in every second passage and air in the other passages. Tests were performed with a traditional open vertical display cabinet, first with a traditional finned-tube coil and thereafter with the new type of heat exchanger placed in the bottom of the display cabinet. The results showed that the same cooling capacity and mean temperature of the “food packages” could be obtained with around 6 K higher inlet temperature of the liquid, -7°C with the traditional coil and -1°C with the new type of heat exchanger, which can lead to considerable energy savings.