Refrigerated containers an expensive option
Reefers are designed to be packed to the brim with produce, sealed and sent from point A to Point B, opened and emptied. When fully loaded the evaporator is designed to force air along the roof of the container down the front of the container and back through the floor channels hence maintain and even temperature for the duration of the trip.
Reefers are not designed to be opened on a regular basis and typically most users require that several different product be stored in the same container, this means the container is partial stock and has walk ways etc. So instead of having a nice level layer of produce to run over the air flow sinks way before reaching the front of the container leading to a short air cycle.
Several issues then present themselves, a build-up of ice at the base of the evaporator, inability to achieve temperature and uneven temperature throughout the container.
The problems don’t end there, refer containers for frozen goods are design to be able to run down to -40C with some specialist ones down to -60C, the average users only requires -18 to -22 C and the condenser are therefore massively oversized leading to higher running cost and short run cycles, increasing wear and tear.
What is seen as a simple solution ends up being a nightmare with of loss of stock and high running costs.