FARM STORAGES FOR APPLES 



19 



Insulation 



No matter what type of building is used, it must be well insulated to make a 

 satisfactory storage. Frame buildings are commonly insulated with fill insula- 

 tion, as the space for the fill is partially provided in the normal construction of 

 the building The most common materials are ground cork, manufactured 

 fibrous materials, and shavings, all of which are good insulators provided they 

 remain dry. Every effort must be made to prevent the entrance of moisture, 

 and the common means for doing this is to line the surface enclosing the insula- 

 tion with waterproof paper. The chief source of moisture is from the air entering 

 the insulation through the outside walls. This moisture is deposited when warm 

 air comes in contact with the cold insulation. Continuous condensation from the 

 outside may eventually moisten the insulating material so much that it loses a 

 great deal of its insulating value. 



The heat transfer through a few types of building construction is given in 

 Table 4. The values under "C" give the number of British thermal units which 

 will pass through one square foot of area per hour per degree of temperature 

 difference. By using this coefficient, it is possible to determine heat leakage 

 for any set of assumed temperature conditions. The columns under "Tons" 

 indicate refrigeration load per 100 square feet for two storage temperatures, 

 with normal air and ground temperatures for New England at apple harvest time. 



Figure 10. Remodeled Structure. 



Basement storage ten feet or more higti obtained by raising old ceiling. Packing shed added on 

 side. Second story used for box storage. 



Regranulated cork and many other types of fill insulation when installed under 

 ideal conditions have as high insulating values as corkboard. In refrigeration 

 practice, however, it is customary to use two inches of fill insulation as equivalent 

 to one inch of corkboard. This is to allow for imperfect packing of the insulation 

 material, settling, and possible absorption of moisture. 



The standard floor construction for apple storages consists of a base of 3 

 inches of concrete on which 2 or 3 inches of corkboard is laid in asphalt. 

 The top of the cork is mopped with asphalt, and a 3-inch concrete wearing 

 floor is laid on top of the cork. 



