COLD STORAGE FOR APPLES AND PEARS 47 



cost by unduly limiting the cooling surface, the condenser capacity, 

 the sizes of fans or ducts, or the efficiency of the insulation. Savings 

 in these items will be small compared with reduced returns from 

 overripe fruit or added power costs projected over many years of 

 operation. When looking for possible economies in cold-storage con- 

 struction it is important not to lose sight of the following essentials : 



1. Sufficient refrigeration must be available to cool the fruit as fast 

 as it comes in. For long-period storage this should be done in the 

 shortest possible time; it is estimated that for each 1,000 boxes of 

 apples received into storage daily at 65° F., approximately 8 tons of 

 refrigeration is required. 



2. The air movement must be sufficient to distribute the refrigera- 

 tion efficiently. In blower-circulating systems there should be at least 

 1,000 cubic feet of air per minute for each ton of refrigeration. In 

 direct-expansion and brine-coil systems the air movement is most 

 satisfactory if the cooling pipes are well distributed over the ceiling 

 area. 



3. The return air must be taken from the room at the points of 

 highest temperature. In general, these are in the upper parts of the 

 room. 



Safety 



Managerial attention should be given to all measures for the safety 

 and health of workmen. Besides safety guards to cover exposed moving 

 parts and openings between floors, all due precautions should be pro- 

 vided against fire hazards and accidents recognized by industrial safety 

 rules, including well-lighted steps, substantial ladders or steps for use 

 in stacking, gas masks for ammonia fumes, and ammonia pressure re- 

 leases that are exhausted outdoors. Employees should not be required 

 to work in blasts of cold air for long periods without being adequately 

 protected by proper clothing. 



The engine room should have doors and windows opening to the 

 outside so that, in case of emergency, ventilation would be possible by 

 opening or breaking them. The outside doors should be kept locked, 

 however, if there is any possibility of children or other persons enter- 

 ing and exposing themselves to danger from the machinery. 



A high-pressure release valve should be installed in the refrigerating 

 equipment and connection made to the outside with a vent pipe so that 

 if the pressure release operates, the refrigerant will not be discharged 

 within the building. A gas mask designed for the refrigerant in use 

 should be hung just inside the outside door so that it can be reached 

 without entering the engine room. To be effective this mask must be 

 kept in operating condition, and employees must be familiar with its 

 use. 



The fire-insurance inspector should be consulted and the recom- 

 mendations for avoiding and fighting fire should be followed. The 

 electric installation should be made in accordance with prevailing 

 codes. If no legal code applies in the locality the insurance inspector 

 should be consulted about the appropriate provisions of the National 

 Electric Code that should be followed in making the installation. 



In order to avoid the possibility of persons being locked inside the 

 storage room, one or more doors or loading ports should be operable 

 from inside the room. 



