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Loading a Reefer to Optimize Quality

Do not run reefer with doors openWhen the ambient temperature is warmer than thecargo, operating the reefer with the rear doors openwill not cool down the cargo. The introduction of hotambient air will heat up the cargo instead.

When hot humid air enters the reefer, moisture con-denses on the cold cooling coil and turns to ice. Ethyleneentering the reefer from genset exhaust may causeripening of fresh produce. Exhaust odor may give prod-uct o� �avors. Cooled air escapes out the rear doorand the cycle continues.

Once loading is complete and the doors are closed,the reefer could run for hours with a partially iced upcooling coil, reducing its cooling e�ect and putting thecargo in danger until the unit completes a defrost cycle.

Packaging frozen & chilled non-live productsFrozen and most chilled non-live products do notrequire air holes in the top and bottom of the cartons.Air �owing around the load is su�cient to remove heatthat has penetrated into the container. The cartonsshould be stacked directly on top of each other to takeadvantage of their strength in the corners. If palletized,the corners of each carton should be supported directlyby the pallet (see Figure A).

Packaging chilled live fresh fruits, vegeta-bles and ornamentals

Cartons require air�ow holes on top and bottom sothat when stacked they align with adjacent cartons(see Figure A). The number, placement, size andshape of the air holes are determined by the productbeing packaged.

If transporting with humidity control, use waximpregnated cardboard or other materials that willnot lose strength in high humidity environments.The strength of a carton is in its corners. Stack car-tons directly on top of each other to minimize crush-ing of the carton below.

If loading cargo on palletsPlace cartons on the pallets so that air �ows up intothe cartons unrestricted.The corners of each carton should be supporteddirectly by the pallet.If wrapping pallets with plastic to provide stability, donot cover bottom or top of cartons.

Figure A: 1. Carton alignment for unrestricted air �ow.2. Strength of cartons in the corners.3. Corners of cartons supported.

Diagrams courtesy of Patrick E. Brecht,

P.E.B. Commodities, Inc .

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General Reefer CargoCheck List — DO:

Follow ”Frozen“ or ”Chilled“cargo speci�cs as required(below).Assure �oor and drains arefree of debris.Block stow entire load in register.Assure weight is distributedevenly in container for maxi-mum stability.Cover the entire �oor.If palletized, place dunnagein center channel between pallets.

Block and brace cargo as necessary.Ensure total weight of cargo, container, chassis, gensetand truck are within legal limits.Set unit at optimal carrying temperature.

Frozen Cargo Speci�cs — DO:Follow general reefer cargo check list (above).Prefreeze cargo before loading.Ensure fresh-air vent is CLOSED .

CHILLED Cargo Speci�cs — DO:Follow general reefer cargo check list (above).Precool cargo before loading.Set unit at carrying temperature, not lower (lower setpoint will not expedite cooling process and may dam-age cargo).Set fresh-air vent as required.

Avoid Cargo Damage — DO NOT:Do not leave open �oor space at front bulkhead orsidewalls (if pallets are placed at front bulkhead, besure to place cardboard under empty pallets).Do not run unit with rear doors open.

Do not load cargo beyond the end of the T-�oor.Do not plug channels at end of T-�oor.Do not load cargo above the red line.Do not set reefer set point at a temperature belowthat required by the cargo (this does not expedite thecooling process).

Refrigeration Unit Air Space Above Cargo Air Flow Rear Doors

SIDE 1 roolf-T fo dnEroolf-T

NO CARGOABOVE LINE

The DOs and DO NOTs of stu�ng air�ow reefers.

Diagrams courtesy of Patrick E. Brecht,

P.E.B. Commodities, Inc .

Loading a Reefer to Optimize Quality

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Loading a Reefer to Optimize Quality

Things “To Do”The SIDE 1 view above illustrates the correct wayto load a ”bottom-air“ reefer with chilled or frozen cargo.In the case of live chilled cargo, covering the entire �oorwith cargo forces the cool air to �ow through the cartonsand product throughout the container. When frozencargo is loaded in this manner, the cold air �ows aroundthe cargo, blanketing the cartons and removing any heatthat enters the reefer container through the walls.

Things “Not To Do”Air always takes the path of least resistance. To the rightare �ve examples that illustrate improperly loaded reefercargo. In three of these cases (SIDE 2-4) air tends to”short circuit“ or �ow past the cartons/product ratherthan through them. SIDE 5 and 6 illustrate restricted air�ow scenarios.

SIDE 2

SIDE 3

SIDE 4

SIDE 5

SIDE 6

Cold

Hot

Ice or Plastic

Air Flow

Diagrams courtesy of Patrick E. Brecht,

P.E.B. Commodities, Inc .

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Loading a Reefer to Optimize Quality

Optimal Loading — Top ViewIn order to force air up and through the cargo, theentire �oor should be covered. Cover the �oor fromthe front bulkhead to the end of the T-�oor. Where the cargo does not cover the �oor, some type of �ller(dunnage, cardboard, etc.) should be used. Do not load past the end of the T-�oor with cargo or �ller.

TOP 1

TOP 2

TOP 3

TOP 4

TOP 5

Refrigeration Unit

Filler

40” x 48” Pallet

Diagrams courtesy of Patrick E. Brecht,

P.E.B. Commodities, Inc .

Wood Bracing

Filler (dunnage or cardboard)

Rear View

Block and brace cargo as necessary using wood.Do not nail dunnage or wood to the container.

Cover �oor between pallets to help force airthrough cargo (as seen in the top view TOP 4above).

Cover the ends of the last two pallets in orderto force air up and through the cartons. Do notblock o� air�ow past the end of the T-�oor.

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Loading a Reefer to Optimize Quality

Blocking and Bracing

Diagrams courtesy of Patrick E. Brecht,

P.E.B. Commodities, Inc .