48 CIRCULAR 740, U. S. DEPARTMENT OF AGRICULTURE 



COLD-STORAGE MANAGEMENT AND PLANT 

 OPERATION 



Many cold-storage plants are not utilized to best advantage, either 

 because of short-sightedness in management or failure to operate at 

 maximum efficiency. During the cooling period many plants take in 

 fruit faster than their equipment can cool it. As a result the fruit is 

 not cooled to the holding temperatures until ripening is well advanced. 

 Several managerial steps can be taken to improve conditions. Com- 

 pressors and auxiliary apparatus need to be in good shape. Condens- 

 ers must be clean and all available condenser surface used. Evaporat- 

 ing coils should be kept as free as possible from frost and the blowers 

 used should circulate the maximum volume of air. Good management 

 includes such handling of the fruit as will utilize the plant to best 

 advantage and such control over the operation of the plant and over the 

 care of the equipment as will keep both at top operating efficiency. 



Handling the Fruit 

 reducing the initial fruit temperature 



The quantity of heat that must be removed from a package of fruit 

 depends largely upon how warm it is when put into storage. If its 

 average temperature can be reduced before storage it will lessen the 

 load imposed on the plant by each box. Fruit picked in the afternoon 

 is ordinarily warmer than that picked in the morning. Picked fruit 

 left in boxes under the tree is considerably cooler in the morning than 

 at evening. In some districts fruit left under the trees overnight or 

 picked in the morning may be at a temperature of 55° F. as against 

 80° late in the afternoon. To cool 1 ton of fruit from 55° to 32° de- 

 mands the removal of 41,400 B. t. u. of field heat, as compared with 

 86,400 B. t. u. for the warmer fruit. The cooling capacity of the cold 

 storage would be more than doubled if the management could arrange 

 for the delivery of the cooler fruit. 



Leaving fruit out in the orchard to cool overnight frequently 

 results in its cooling faster than it would in a cold-storage plant that 

 is being crowded beyond its capacity. It also results in the fruit 

 already in storage having a chance to cool faster and represents an 

 exceptional situation where a few hours' delay in the orchard increases 

 its storage life. The advantages to be gained warrants the curtailing 

 of afternoon deliveries with such fruits as apples and pears and 

 correspondingly increasing early morning deliveries, especially in 

 plants of limited cooling capacity, even at the expense of some diffi- 

 culty and inconvenience in handling and hauling. 



SEGREGATION OF LONG-STORAGE FRUIT 



The Delicious variety causes the most serious storage problem 

 in western apple districts because of its storage-temperature require- 

 ments, its large tonnage, and its relatively short harvest period. If 

 the cooling capacity is sufficient to cool all these apples as fast as 

 harvested, it might be desirable to cool all the fruit as quickly as 

 possible. Since this is not usually the case, an attempt to cool all 



