A multi-band air curtain forms a separation barrier at an interface between a first environment having a fluid at a first condition and a second environment having a fluid at a second condition. A first stream (55) of a fluid is directed along a first path (45) generally parallel to the interface between the first environment and the second environment. A second stream (65) of fluid is directed along a second path (75) generally outwardly at an angle of divergence with the first path (45). A third stream (65) of a fluid is directed along a third path (95) between the first path (45) and the second path (75) at a first interior angle with said first path (45) and at a second interior angle with said second path (75). A refrigerated merchandiser (10) is also disclosed having a display case having an interior defining a product display region (30) having an open front and first (34), second (70) and third (58) air outlets for directing first (55), second (65) and third air (85) streams, respectively, across the open front of the refrigerated merchandiser in a divergent manner.