The functioning of extended defrost in Starcool’s new design: The (extended) defrosting of Starcool’s new designs of return air grid and evap. fans

In some frozen mode shipments the moisture load may be so high that frost accumulates in the reefer unit. This happens on components above the evaporator coil, the highest component being the return air grid. The extended defrost function, available in the current controller software, suffices to also defrost the return air grid. Now Starcool is considering the launch of a new design for the return air grid and a new design for the evaporator fan motor assembly. The aim of this test is to experimentally assess if the existing extended defrost function suffices to remove all frost in case of the new designs. To that end, a reefer container with a Starcool refrigeration unit is placed in a climate chamber. The unit is set at -20 °C and it is subjected to an extreme moisture load for multiple days. The results show that the existing extended defrost function suffices to remove all frost from the new designs for return air grid and the evaporator fan motor assembly. The areas with bigger openings in the new return air grid are even beneficial in the sense that they clog less quickly.