University of California Davis - Forced Air Cooling Test Report

The University of California Davis (UC Davis) conducted forced air cooling tests of the Fresh-Pakk TM Racks to measure the temperature change in field picked strawberries. The cooling times were reduced using the Freah-Pakk TM Racks as compared to cardboard and clam shell packed strawberries. The hard data is currently being put together by Professor James Thompson of the Biological & Agriculture Engineering Department at UC Davis. As soon as the report is completed it will be made available here.

UC Davis - Biological & Agriculture Engineering Department

Dear Chip Mandela;

We have finally finished the laboratory forced air cooling tests on your strawberry packaging system. We simulated a pallet load where the air flowed parallel to the 20 inch dimension of two trays and operated with a 0.37 inch of water column pressure drop across the the pallet. This is a standard procedure we use and simulates air flow often found in commercial coolers.

The Fresh-Pakk TM Racks without lids allowed 7/8 ths cooling in about 40 minutes, the same Fresh-Pakk TM Racks with lids allowed cooling in about 50 minutes.

About two years ago we tested more traditional clam shell containers in side-vented 16" x 20" trays and found the better designs to have 7/8 ths cooling times of about 70 minutes. Since that time there have been some new designs which may cool faster, but we have not tested these.

7/8 ths cooling produces berry temperatures in the mid 30?s. Many operations cool to lower temperatures and approach 15/16 ths cooling. To determine 15/16 cooling times multiply the 7/8 ths times above by 1.33. If you want more details on these cooling calculations you might want to order "Commercial Cooling of fruits vegetables and flowers" UC DANR publication 21567. Call (800) 994-8849 for ordering details.

I hope this information is helpful.


James F. Thompson

University of California Davis
Biological & Agriculture Engineering Department
One Shields Avenue
Davis, CA 95616-5294

Tel (530) 752-6167
Fax (530) 752-2640