COLD STORAGE FOR APPLES AND PEARS 



51 



stacking. It is important to maintain an air space between rows at all 

 points. A uniform spacing of 2 to 3 inches between rows has been 

 found to be practically as effective in permitting cooling as spacing up 

 to 5 or 6 inches if there is sufficient headroom between boxes and ceiling. 

 Careless stacking, however, in which some boxes in one row touch or 

 approach those in another, restricts air movement and retards cooling. 

 A spacing of 2 to 3 inches is needed to release box trucks when trucking 

 fruit into rows, and convenience in trucking has regulated spacing in 

 most storage houses. 

 To overcome slight ir- 

 regularities in stack- 

 ing, 3 inches may be 

 considered a satisfac- 

 tory spacing for the 

 bottom boxes. The 

 rows should be so laid 

 out that the general 

 direction of air move- 

 ment is along the rows 

 instead of across them. 



Stacking packages 

 in contact with out- 

 side walls or floors 

 should be avoided, as 

 there is some heat 

 transfer through con- 

 duction that affects the 

 temperature of fruit 

 in outside or bottom 

 packages. When 

 boxes or cartons are 

 being stacked, spacing 

 between the walls and 

 the packages may be 

 insured by using side 

 rails, as illustrated in 

 figure 20 or by fasten- 

 ing 2- by 6-inch planks 

 to the floor around the 

 outside of the room. 

 On a ground floor 

 it is particularly de- 

 sirable to provide an air space beneath fruit by stacking on strips 

 or on a false floor. 



In large rooms warm fruit may be brought in over a long period ; 

 this means that fruit that has been in the room for some time and has 

 cooled is sometimes warmed up by incoming fruit. This effect is un- 

 avoidable in some rooms, but by judicious stacking it can be kept at 

 a minimum. In some cases it is possible to stack the first fruit brought 

 in nearest to the air-discharge ports so that after it is cooled it is not 

 exposed to air coming from warm fruit brought in later. In plants 

 that have two levels separated by a slotted floor it is good practice to 

 load the lower floor first so that as the fruit on the upper floor is cooled 

 it will not be affected by warm air rising from warmer fruit below. 



Figuee 20. — Side rails used in cold-storage rooms to 

 prevent stacking against the walls. 



