DA-88-17-4 — Design Criteria for Efficient and Cost Effective Forced Air Cooling Systems for Fruits and Vegetables

Numerous variables affect product cooling rate and/or overall cost of forced-air cooling systems for fruits and vegetables. These include: product size, shape and thermal properties; product configuration (whether in bulk or packed in shipping cartons); carton vent area; depth product load during cooling; initial product temperature; desired final product temperature; flow rate, temperature, and relative humidity, of the cooling air; ambient temperature; time of operation per year; unit costs of cooling space, heat exchangers, compressors, and fans; electric power cost; maintenance cost; labor cost; and interest rate. An engineering-economic model was used to study the influence of each of these variables as they affect cooling time and/or cooling cost. Interactions between some of these variables were also analyzed to determine the optimum values which can give a minimum cooling cost for certain specified conditions. Results, presented in the form of graphs and tables will be useful to designers of forced-air cooling systems for fruits and vegetables.