16 



RBDUCIN*; ENERGY COSTS IN CA STORAGE 



J. A. Bartsch 



Cornell University 



Agricultural Engineer 



Dedication 



This work is dedicated to Professor Robert M. Smock, who in 1938 

 published the results of his research on evaporator fan cycling to save energy. 

 We are grateful for his constant support and encouragement in this project and 

 in all fruit storage programs. Dr. Smock suffered a fatal heart attack on April 

 22, 1986 as he walked across the Cornell campus to his office in the Pomology 

 Department. 



Introduct ion 



The concept of reducing cold storage energy use through evaporator fan 

 cycling is not new. In 1938 R. M. Smock (2), a Pomologist at Cornell 

 University, wrote of his work, "Certainly no differences were indicated in this 

 study which would justify the extra power cost of continuous blower operation." 

 Smock's study indicated that fan operating time could be reduced by 45% with 

 no detrimental effect on fruit quality and condition. Thirty plus years have 

 elapsed, and now the merits of this original research are being discovered and 

 applied to modern CA storage in New York. 



Storage Technology 



Fruit storage technology has changed tremendously since the first cold 

 storages were built in New York State. The handling, cooling, and storage 

 milestones are highlighted in Table 1. 



Table 1. Commercial loading and cooling rates for apples. 



Year 



Loading 

 Period 



Cool ing 

 Time 



Room 

 Atmosphere 



Handling 

 Method 



1924 

 1938 

 1945 

 1965 

 1986 



2-3 weeks 

 2 weeks 

 1 week 

 1 week 

 5 days 



1 week 



1 week 

 3-4 days 

 2-3 days 

 "overnight" 



Air 

 Air 

 CA 

 CA 

 "Rapid" 



CA 



Barrels 



Bu. Box 



Bu. Box 



20 Bu. Bin 



20 Bu. Bin 



The industry began to use on-farm refrigeration for apples stored in 

 barrels around 1924. Professor Smock's study involved refrigerated air storage 

 of apples in bushel boxes in 1938. Around 1945, commercial CA storage was 

 begun, and by 1965, the importance of faster cooling was recognized and 20- 

 bushel pallet bins were in widespread use. Currently, commercial operations are 

 striving for overnight cooling and rapid CA. 



