The air straighter characteristic plays a very important role on the performance of vertical and stand refrigerated display case. The transient temperature of the display case shelves was measured for studying the temperature variation and distribution in the vertical display case by changing the number and the velocity of air straighter. The result shows that it is necessary to keep three air straighters in a vertical open low temperature display case and the performance of the display case can be improved by selecting reasonable air straighter velocities.

PC honeycomb has excellent compressive strength act as air straighter in refrigerated display cases. Polycore provide air straighter has excellent properties:

1. Core uniformality, inside smoothness, cleanness, surface level off.

2. PC raw material is safe for using as air straighter in showcase.

3. Lower shrink rate when temperature drop to -30 degree. This is very important for durable life of air straighter and provide installation safety for showcase manufacturer and supermarket operator.