- 20 - 



best results that have been observed for cooling apples . The performance at 

 the second test location was slower than any previously observed tests of 

 cooling unpacked apples in pallet loads of standard boxes. Therefore, the 

 results are not directly comparable. 



Table 3. — Half-cooling time and approach temperature for 9 types of pallet 

 boxes and for pallet loads of unpacked standard apple boxes 



Type of box 



: Half- 



-cooling 



Approach 





time 



1/ 



temperature 2/ 





Hours 





Index 3/ 



Degrees F. 



Test No. 1 











Standard apple box (loose). . . 



16.1 





100 



0.7 



Comm.-3 (fiberboard liners) . . 



29.8 





185 : 



.7 



Comm.-2 (1&" bottom slot). .. . 



: 26.7 





166 



.9 



Comm.-2M (no vents) ...... 



: 29.2 





181 



.9 



AMS-2 (spaced sides, solid 











bottom). ........... 



15.5 





96 



.8 



ARS-1 (solid sides, spaced 











bottom). ........... 



: 15.6 





97 



.8 



Test No. 2 











Standard apple box (loose). . . 



30.9 





100 



.7 



Comm.-l (fiberboard liners) . . 



33.0 





107 



.5 



AMS-1 (solid sides, spaced 













32.4 





105 



.5 



AMS-3 (spaced bottom, no 











pallet) o 



32.4 





105 



.6 



AMS-4 (spaced sides and 







10.0 





32 



.2 



1/ Half-cooling time is the time required to reduce the temperature of the 

 fruit one-half the way from the initial fruit temperature to cold storage 

 air temperature. 



2/ The approach temperature is the temperature difference between the 

 cooled commodity and the adjacent air after equilibrium is reached. 



Zj Time for standard apple box = 100. 



The first test shows that the 2 boxes with good ventilation — the box 

 with solid sides and spaced bottom, and the box with solid bottom and spaced 

 sides — cooled slightly faster than pallet loads of standard boxes. The other 

 boxes in this test, which had a low percentage of free area, took from 66 to 

 85 percent longer to cool than the standard apple boxes. 



The pallet box with spaced sides and spaced bottom, and with the 

 greatest free area of any box in the 2 tests, was far superior to all boxes 



